1
623012fc
LT6230/LT6230-10
LT6231/LT6232
Typical applicaTion
FeaTures DescripTion
215MHz, Rail-to-Rail Output,
1.1nV/Hz, 3.5mA Op Amp Family
The LT
®
6230/LT6231/LT6232 are single/dual/quad low
noise, rail-to-rail output unity-gain stable op amps that
feature 1.1nV/√Hz noise voltage and draw only 3.5mA of
supply current per amplifier. These amplifiers combine
very low noise and supply current with a 215MHz gain-
bandwidth product, a 70V/µs slew rate and are optimized
for low supply voltage signal conditioning systems. The
LT6230-10 is a single amplifier optimized for higher gain
applications resulting in higher gain bandwidth and slew
rate. The LT6230 and LT6230-10 include an enable pin
that can be used to reduce the supply current to less
than 10µA.
The amplifier family has an output that swings within 50mV
of either supply rail to maximize the signal dynamic range
in low supply applications and is specified on 3.3V, 5V and
±5V supplies. The en ISUPPLY product of 1.9 per amplifier
is among the most noise efficient of any op amp.
The LT6230/LT6230-10 are available in the 6-lead SOT-23
package and the LT6231 dual is available in the 8-pin SO
package with standard pinouts. For compact layouts,
the dual is also available in a tiny dual fine pitch leadless
package (DFN). The LT6232 is available in the 16-pin
SSOP package.
Low Noise Low Power Instrumentation Amplifier
applicaTions
n Low Noise Voltage: 1.1nV/√Hz
n Low Supply Current: 3.5mA/Amp Max
n Low Offset Voltage: 350µV Max
n Gain Bandwidth Product:
LT6230: 215MHz; AV ≥ 1
LT6230-10: 1450MHz; AV ≥ 10
n Wide Supply Range: 3V to 12.6V
n Output Swings Rail-to-Rail
n Common Mode Rejection Ratio: 115dB Typ
n Output Current: 30mA
n Operating Temperature Range: –40°C to 85°C
n LT6230 Shutdown to 10µA Maximum
n LT6230/LT6230-10 in a Low Profile (1mm)
ThinSOT™ Package
n Dual LT6231 in 8-Pin SO and Tiny DFN Packages
n LT6232 in a 16-Pin SSOP Package
n Ultrasound Amplifiers
n Low Noise, Low Power Signal Processing
n Active Filters
n Driving A/D Converters
n Rail-to-Rail Buffer Amplifiers
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. ThinSOT is a trademark of Linear Technology Corporation. All other
trademarks are the property of their respective owners.
+
R6
499Ω
LT6202
VS+
VOUT
IN+
IN+
1/2 LT6231
VS
VS+
+
1/2 LT6231
R7
499Ω
R4
499Ω
R2
196Ω
R1
10Ω
R3
196Ω R5
499Ω
623012 TA01a
AV = 40
BW = 5.1MHz
VS = ±1.5V to ±5V
IS = 10mA
EN = 5.8µVRMS INPUT REFERRED,
MEASUREMENT BW = 8MHz
VS
Noise Voltage and Unbalanced
Noise Current vs Frequency
FREQUENCY (Hz)
NOISE VOLTAGE (nV/√Hz)
6
5
4
3
2
1
010 1k 10k 100k
623012 TA01b
100
VS = ±2.5V
TA = 25°C
VCM = 0V
NOISE VOLTAGE
NOISE CURRENT
UNBALANCED NOISE CURRENT (pA/√Hz)
6
5
4
3
2
1
0
LT6230/LT6230-10
LT6231/LT6232
2
623012fc
absoluTe MaxiMuM raTings
Total Supply Voltage (V+ to V) .............................. 12.6V
Input Current (Note 2) ......................................... ±40mA
Output Short-Circuit Duration (Note 3) ............ Indenite
Operating Temperature Range (Note 4)....40°C to 85°C
Specified Temperature Range (Note 5) ....40°C to 85°C
Junction Temperature ........................................... 150°C
(Note 1)
6 V+
5 ENABLE
4 –IN
OUT 1
TOP VIEW
S6 PACKAGE
6-LEAD PLASTIC TSOT-23
V 2
+IN 3
TJMAX = 150°C, θJA = 250°C/W
TOP VIEW
DD PACKAGE
8-LEAD (3mm × 3mm) PLASTIC DFN
5
6
7
8
4
3
2
1OUT A
–IN A
+IN A
V
V+
OUT B
–IN B
+IN B
+
+
TJMAX = 125°C, θJA = 160°C/W
UNDERSIDE METAL CONNECTED TO V (PCB CONNECTION OPTIONAL)
TOP VIEW
V+
OUT B
–IN B
+IN B
OUT A
–IN A
+IN A
V
S8 PACKAGE
8-LEAD PLASTIC SO
1
2
3
4
8
7
6
5
+
+
TJMAX = 150°C, θJA = 200°C/W
TOP VIEW
GN PACKAGE
16-LEAD NARROW PLASTIC SSOP
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
OUT A
–IN A
+IN A
V+
+IN B
–IN B
OUT B
NC
OUT D
–IN D
+IN D
V
+IN C
–IN C
OUT C
NC
+
+
+
+
AD
B C
TJMAX = 150°C, θJA = 135°C/W
pin conFiguraTion
Junction Temperature (DD Package) .................... 125°C
Storage Temperature Range .................. 65°C to 150°C
Storage Temperature Range
(DD Package) ........................................ 65°C to 125°C
Lead Temperature (Soldering, 10 sec) ...................300°C
3
623012fc
LT6230/LT6230-10
LT6231/LT6232
elecTrical characTerisTics
TA = 25°C, VS = 5V, 0V; VS = 3.3V, 0V; VCM = VOUT = half supply,
ENABLE = 0V, unless otherwise noted.
orDer inForMaTion
LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION SPECIFIED TEMPERATURE RANGE
LT6230CS6#PBF LT6230CS6#TRPBF LTAFJ 6-Lead Plastic TS0T-23 0°C to 70°C
LT6230IS6#PBF LT6230IS6#TRPBF LTAFJ 6-Lead Plastic TS0T-23 –40°C to 85°C
LT6230CS6-10#PBF LT6230CS6-10#TRPBF LTAFK 6-Lead Plastic TS0T-23 0°C to 70°C
LT6230IS6-10#PBF LT6230IS6-10#TRPBF LTAFK 6-Lead Plastic TS0T-23 –40°C to 85°C
LT6231CS8#PBF LT6230CS8#TRPBF 6231 8-Lead Plastic SO 0°C to 70°C
LT6231IS8#PBF LT6230IS8#TRPBF 6231I 8-Lead Plastic SO –40°C to 85°C
LT6231CDD#PBF LT6231CDD#TRPBF LAEU 8-Lead (3mm × 3mm) Plastic DFN 0°C to 70°C
LT6231IDD#PBF LT6231IDD#TRPBF LAEU 8-Lead (3mm × 3mm) Plastic DFN –40°C to 85°C
LT6232CGN#PBF LT6232CGN#TRPBF 6232 16-Lead Narrow Plastic SSOP 0°C to 70°C
LT6232IGN#PBF LT6232IGN#TRPBF 6232I 16-Lead Narrow Plastic SSOP –40°C to 85°C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
Consult LTC Marketing for information on non-standard lead based finish parts.
For more information on lead free part marking, go to: http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
VOS Input Offset Voltage LT6230S6, LT6230S6-10
LT6231S8, LT6232GN
LT6231DD
100
50
75
500
350
450
µV
µV
µV
Input Offset Voltage Match
(Channel-to-Channel) (Note 6) 100 600 µV
IBInput Bias Current 5 10 µA
IB Match (Channel-to-Channel) (Note 6) 0.1 0.9 µA
IOS Input Offset Current 0.1 0.6 µA
Input Noise Voltage 0.1Hz to 10Hz 180 nVP-P
enInput Noise Voltage Density f = 10kHz, VS = 5V 1.1 1.7 nV/√Hz
in Input Noise Current Density, Balanced Source
Input Noise Current Density, Unbalanced Source f = 10kHz, VS = 5V, RS = 10k
f = 10kHz, VS = 5V, RS = 10k 1
2.4 pA/√Hz
pA/√Hz
Input Resistance Common Mode
Differential Mode 6.5
7.5
CIN Input Capacitance Common Mode
Differential Mode 2.9
7.7 pF
pF
AVOL Large-Signal Gain VS = 5V, VO = 0.5V to 4.5V, RL = 10k to VS/2
VS = 5V, VO = 0.5V to 4.5V, RL = 1k to VS/2
VS = 5V, VO = 1V to 4V, RL = 100Ω to VS/2
105
21
5.4
200
40
9
V/mV
V/mV
V/mV
VS = 3.3V, VO = 0.65V to 2.65V, RL = 10k to VS/2
VS = 3.3V, VO = 0.65V to 2.65V, RL = 1k to VS/2 90
16.5 175
32 V/mV
V/mV
VCM Input Voltage Range Guaranteed by CMRR, VS = 5V, 0V
Guaranteed by CMRR, VS = 3.3V, 0V 1.5
1.15 4
2.65 V
V
CMRR Common Mode Rejection Ratio VS = 5V, VCM = 1.5V to 4V
VS = 3.3V, VCM = 1.15V to 2.65V 90
90 115
115 dB
dB
CMRR Match (Channel-to-Channel) (Note 6) VS = 5V, VCM = 1.5V to 4V 84 120 dB
LT6230/LT6230-10
LT6231/LT6232
4
623012fc
elecTrical characTerisTics
TA = 25°C, VS = 5V, 0V; VS = 3.3V, 0V; VCM = VOUT = half supply,
ENABLE = 0V, unless otherwise noted.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
PSRR Power Supply Rejection Ratio VS = 3V to 10V 90 115 dB
PSRR Match (Channel-to-Channel) (Note 6) VS = 3V to 10V 84 115 dB
Minimum Supply Voltage (Note 7) 3 V
VOL Output Voltage Swing Low (Note 8) No Load
ISINK = 5mA
VS = 5V, ISINK = 20mA
VS = 3.3V, ISINK = 15mA
4
85
240
185
40
190
460
350
mV
mV
mV
mV
VOH Output Voltage Swing High (Note 8) No Load
ISOURCE = 5mA
VS = 5V, ISOURCE = 20mA
VS = 3.3V, ISOURCE = 15mA
5
90
325
250
50
200
600
400
mV
mV
mV
mV
ISC Short-Circuit Current VS = 5V
VS = 3.3V ±30
±25 ±45
±40 mA
mA
ISSupply Current per Amplifier
Disabled Supply Current per Amplifier
ENABLE = V+ – 0.35V 3.15
0.2 3.5
10 mA
µA
IENABLE ENABLE Pin Current ENABLE = 0.3V –25 –75 µA
VLENABLE Pin Input Voltage Low 0.3 V
VHENABLE Pin Input Voltage High V+ – 0.35V V
Output Leakage Current ENABLE = V+ – 0.35V, VO = 1.5V to 3.5V 0.2 10 µA
tON Turn-On Time ENABLE = 5V to 0V, RL = 1k, VS = 5V 300 ns
tOFF Turn-Off Time ENABLE = 0V to 5V, RL = 1k, VS = 5V 41 µs
GBW Gain-Bandwidth Product Frequency = 1MHz, VS = 5V
LT6230-10 200
1300 MHz
MHz
SR Slew Rate VS = 5V, A
V = –1, RL = 1k, VO = 1.5V to 3.5V 42 60 V/µs
LT6230-10, VS = 5V, AV = –10, RL = 1k,
VO = 1.5V to 3.5V 250 V/µs
FPBW Full-Power Bandwidth VS = 5V, VOUT = 3VP-P (Note 9) 4.8 6.3 MHz
LT6230-10, HD2 = HD3 = ≤1% 11 MHz
tSSettling Time (LT6230, LT6231, LT6232) 0.1%, VS = 5V, VSTEP = 2V, AV = –1, RL = 1k 55 ns
5
623012fc
LT6230/LT6230-10
LT6231/LT6232
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNIT
VOS Input Offset Voltage LT6230CS6, LT6230CS6-10
LT6231CS8, LT6232CGN
LT6231CDD
l
l
l
600
450
550
µV
µV
µV
Input Offset Voltage Match
(Channel-to-Channel) (Note 6)
l800 µV
VOS TC Input Offset Voltage Drift (Note 10) VCM = Half Supply l0.5 3 µV/°C
IBInput Bias Current l11 µA
IB Match (Channel-to-Channel) (Note 6) l1 µA
IOS Input Offset Current l0.7 µA
AVOL Large-Signal Gain VS = 5V, VO = 0.5V to 4.5V, RL = 10k to VS/2
VS = 5V, VO = 0.5V to 4.5V, RL = 1k to VS/2
VS = 5V, VO = 1V to 4V, RL = 100Ω to VS/2
l
l
l
78
17
4.1
V/mV
V/mV
V/mV
VS = 3.3V, VO = 0.65V to 2.65V, RL = 10k to VS/2
VS = 3.3V, VO = 0.65V to 2.65V, RL = 1k to VS/2
l
l
66
13 V/mV
V/mV
VCM Input Voltage Range Guaranteed by CMRR
VS = 5V, 0V
Vs = 3.3V, 0V
l
l
1.5
1.15
4
2.65
V
V
CMRR Common Mode Rejection Ratio VS = 5V, VCM = 1.5V to 4V
VS = 3.3V, VCM = 1.15V to 2.65V
l
l
90
85 dB
dB
CMRR Match (Channel-to-Channel) (Note 6) VS = 5V, VCM = 1.5V to 4V l84 dB
PSRR Power Supply Rejection Ratio VS = 3V to 10V l85 dB
PSRR Match (Channel-to-Channel) (Note 6) VS = 3V to 10V l79 dB
Minimum Supply Voltage (Note 7) l3 V
VOL Output Voltage Swing Low (Note 8) No Load
ISINK = 5mA
VS = 5V, ISINK = 20mA
VS = 3.3V, ISINK = 15mA
l
l
l
l
50
200
500
380
mV
mV
mV
mV
VOH Output Voltage Swing High (Note 8) No Load
ISOURCE = 5mA
VS = 5V, ISOURCE = 20mA
VS = 3.3V, ISOURCE = 15mA
l
l
l
l
60
215
650
430
mV
mV
mV
mV
ISC Short-Circuit Current VS = 5V
VS = 3.3V
l
l
±25
±20 mA
mA
ISSupply Current per Amplifier
Disabled Supply Current per Amplifier
ENABLE = V+ – 0.25V
l
l
14.2 mA
µA
IENABLE ENABLE Pin Current ENABLE = 0.3V l–85 µA
VLENABLE Pin Input Voltage Low l0.3 V
VHENABLE Pin Input Voltage High lV+ – 0.25V V
Output Leakage Current ENABLE = V+ – 0.25V, VO = 1.5V to 3.5V l1 µA
tON Turn-On Time ENABLE = 5V to 0V, RL = 1k, VS = 5V l300 ns
tOFF Turn-Off Time ENABLE = 0V to 5V, RL = 1k, VS = 5V l65 µs
SR Slew Rate VS = 5V, AV = –1, RL = 1k, VO = 1.5V to 3.5V l35 V/µs
LT6230-10, AV = –10, RL = 1k, VO = 1.5V to 3.5V l225 V/µs
FPBW Full-Power Bandwidth (Note 9) VS = 5V, VOUT = 3VP-P; LT6230C, LT6231C,
LT6232C
l3.7 MHz
elecTrical characTerisTics
The l denotes the specifications which apply over the 0°C < TA < 70°C
temperature range. VS = 5V, 0V; VS = 3.3V, 0V; VCM = VOUT = half supply, ENABLE = 0V, unless otherwise noted.
LT6230/LT6230-10
LT6231/LT6232
6
623012fc
elecTrical characTerisTics
The l denotes the specifications which apply over the –40°C < TA < 85°C
temperature range. VS = 5V, 0V; VS = 3.3V, 0V; VCM = VOUT = half supply, ENABLE = 0V, unless otherwise noted. (Note 5)
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
VOS Input Offset Voltage LT6230IS6, LT6230IS6-10
LT6231IS8, LT6232IGN
LT6231IDD
l
l
l
700
550
650
µV
µV
µV
Input Offset Voltage Match
(Channel-to-Channel) (Note 6)
l1000 µV
VOS TC Input Offset Voltage Drift (Note 10) VCM = Half Supply l0.5 3 µV/°C
IBInput Bias Current l12 µA
IB Match (Channel-to-Channel) (Note 6) l1.1 µA
IOS Input Offset Current l0.8 µA
AVOL Large-Signal Gain VS = 5V, VO = 0.5V to 4.5V, RL = 10k to VS/2
VS = 5V, VO = 0.5V to 4.5V, RL = 1k to VS/2
VS = 5V, VO = 1V to 4V, RL = 100Ω to VS/2
l
l
l
72
16
3.6
V/mV
V/mV
V/mV
VS = 3.3V, VO = 0.65V to 2.65V, RL = 10k to VS/2
VS = 3.3V, VO = 0.65V to 2.65V, RL = 1k to VS/2
l
l
60
12 V/mV
V/mV
VCM Input Voltage Range Guaranteed by CMRR
VS = 5V, 0V
VS = 3.3V, 0V
l
l
1.5
1.15
4
2.65
V
V
CMRR Common Mode Rejection Ratio VS = 5V, VCM = 1.5V to 4V
VS = 3.3V, VCM = 1.15V to 2.65V
l
l
90
85 dB
dB
CMRR Match (Channel-to-Channel) (Note 6) VS = 5V, VCM = 1.5V to 4V l84 dB
PSRR Power Supply Rejection Ratio VS = 3V to 10V l85 dB
PSRR Match (Channel-to-Channel) (Note 6) VS = 3V to 10V l79 dB
Minimum Supply Voltage (Note 7) l3 V
VOL Output Voltage Swing Low (Note 8) No Load
ISINK = 5mA
VS = 5V, ISINK = 15mA
VS = 3.3V, ISINK = 15mA
l
l
l
l
60
210
510
390
mV
mV
mV
mV
VOH Output Voltage Swing High (Note 6) No Load
ISOURCE = 5mA
VS = 5V, ISOURCE = 20mA
VS = 3.3V, ISOURCE = 15mA
l
l
l
l
70
220
675
440
mV
mV
mV
mV
ISC Short-Circuit Current VS = 5V
VS = 3.3V
l
l
±15
±15 mA
mA
ISSupply Current per Amplifier
Disabled Supply Current per Amplifier
ENABLE = V+ – 0.2V
l
l
14.4 mA
µA
IENABLE ENABLE Pin Current ENABLE = 0.3V l–100 µA
VLENABLE Pin Input Voltage Low l0.3 V
VHENABLE Pin Input Voltage High lV+ – 0.2V V
Output Leakage Current ENABLE = V+ – 0.2V, VO = 1.5V to 3.5V l1 µA
tON Turn-On Time ENABLE = 5V to 0V, RL = 1k, VS = 5V l300 ns
tOFF Turn-Off Time ENABLE = 0V to 5V, RL = 1k, VS = 5V l72 µs
SR Slew Rate VS = 5V, AV = –1, RL = 1k, VO = 1.5V to 3.5V l31 V/µs
LT6230-10, AV = –10, RL = 1k, VO = 1.5V to 3.5V l185 V/µs
FPBW Full-Power Bandwidth (Note 9) VS = 5V, VOUT = 3VP-P; LT6230I, LT6231I,
LT6232I
l3.3 MHz
7
623012fc
LT6230/LT6230-10
LT6231/LT6232
elecTrical characTerisTics
TA = 25°C, VS = ±5V, VCM = VOUT = 0V, ENABLE = 0V, unless otherwise noted.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
VOS Input Offset Voltage LT6230, LT6230-10
LT6231S8, LT6232GN
LT6231DD
100
50
75
500
350
450
µV
µV
µV
Input Offset Voltage Match
(Channel-to-Channel) (Note 6) 100 600 µV
IBInput Bias Current 5 10 µA
IB Match (Channel-to-Channel) (Note 6) 0.1 0.9 µA
IOS Input Offset Current 0.1 0.6 µA
Input Noise Voltage 0.1Hz to 10Hz 180 nVP-P
enInput Noise Voltage Density f = 10kHz 1.1 1.7 nV/√Hz
inInput Noise Current Density, Balanced Source
Input Noise Current Density, Unbalanced Source f = 10kHz, RS = 10k
f = 10kHz, RS = 10k 1
2.4 pA/√Hz
pA/√Hz
Input Resistance Common Mode
Differential Mode 6.5
7.5
CIN Input Capacitance Common Mode
Differential Mode 2.4
6.5 pF
pF
AVOL Large-Signal Gain VO = ±4.5V, RL = 10k
VO = ±4.5V, RL = 1k
VO = ±2V, RL = 100Ω
140
35
8.5
260
65
16
V/mV
V/mV
V/mV
VCM Input Voltage Range Guaranteed by CMRR –3 4 V
CMRR Common Mode Rejection Ratio VCM = –3V to 4V 95 120 dB
CMRR Match (Channel-to-Channel) (Note 6) VCM = –3V to 4V 89 125 dB
PSRR Power Supply Rejection Ratio VS = ±1.5V to ±5V 90 115 dB
PSRR Match (Channel-to-Channel) (Note 6) VS = ±1.5V to ±5V 84 115 dB
VOL Output Voltage Swing Low (Note 8) No Load
ISINK = 5mA
ISINK = 20mA
4
85
240
40
190
460
mV
mV
mV
VOH Output Voltage Swing High (Note 8) No Load
ISOURCE = 5mA
ISOURCE = 20mA
5
90
325
50
200
600
mV
mV
mV
ISC Short-Circuit Current ±30 mA
ISSupply Current per Amplifier
Disabled Supply Current per Amplifier
ENABLE = 4.65V 3.3
0.2 3.9 mA
µA
IENABLE ENABLE Pin Current ENABLE = 0.3V –35 –85 µA
VLENABLE Pin Input Voltage Low 0.3 V
VHENABLE Pin Input Voltage High 4.65 V
Output Leakage Current ENABLE = V+ – 4.65V, VO = ±1V 0.2 10 µA
tON Turn-On Time ENABLE = 5V to 0V, RL = 1k 300 ns
tOFF Turn-Off Time ENABLE = 0V to 5V, RL = 1k 62 µs
GBW Gain-Bandwidth Product Frequency = 1MHz
LT6230-10 150
1000 215
1450 MHz
MHz
SR Slew Rate AV = –1, RL = 1k, VO = –2V to 2V 50 70 V/µs
LT6230-10, AV = –10, RL = 1k, VO = –2V to 2V 320 V/µs
FPBW Full-Power Bandwidth VOUT = 3VP-P (Note 9) 5.3 7.4 MHz
LT6230-10, HD2 = HD3 ≤ 1% 11 MHz
tSSettling Time (LT6230, LT6231, LT6232) 0.1%, VSTEP = 2V, AV = –1, RL = 1k 50 ns
LT6230/LT6230-10
LT6231/LT6232
8
623012fc
elecTrical characTerisTics
The l denotes the specifications which apply over the 0°C < TA < 70°C
temperature range. VS = ±5V, VCM = VOUT = 0V, ENABLE = 0V, unless otherwise noted.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
VOS Input Offset Voltage LT6230CS6, LT6230CS6-10
LT6231CS8, LT6232CGN
LT6231CDD
l
l
l
600
450
550
µV
µV
µV
Input Offset Voltage Match
(Channel-to-Channel) (Note 6)
l800 µV
VOS TC Input Offset Voltage Drift (Note 10) l0.5 3 µV/°C
IBInput Bias Current l11 µA
IB Match (Channel-to-Channel) (Note 6) l1 µA
IOS Input Offset Current l0.7 µA
AVOL Large-Signal Gain VO = ±4.5V, RL = 10k
VO = ±4.5V, RL = 1k
VO = ±2V, RL = 100Ω
l
l
l
100
27
6
V/mV
V/mV
V/mV
VCM Input Voltage Range Guaranteed by CMRR l–3 4 V
CMRR Common Mode Rejection Ratio VCM = –3V to 4V l95 dB
CMRR Match (Channel-to-Channel) (Note 6) VCM = –3V to 4V l89 dB
PSRR Power Supply Rejection Ratio VS = ±1.5V to ±5V l85 dB
PSRR Match (Channel-to-Channel) (Note 6) VS = ±1.5V to ±5V l79 dB
VOL Output Voltage Swing Low (Note 8) No Load
ISINK = 5mA
ISINK = 20mA
l
l
l
50
200
500
mV
mV
mV
VOH Output Voltage Swing High (Note 8) No Load
ISOURCE = 5mA
ISOURCE = 20mA
l
l
l
60
215
650
mV
mV
mV
ISC Short-Circuit Current l±25 mA
ISSupply Current per Amplifier
Disabled Supply Current per Amplifier
ENABLE = 4.75V
l
l
14.6 mA
µA
IENABLE ENABLE Pin Current ENABLE = 0.3V l–95 µA
VLENABLE Pin Input Voltage Low l0.3 V
VHENABLE Pin Input Voltage High l4.75 V
Output Leakage Current ENABLE = 4.75V, VO = ±1V l1 µA
tON Turn-On Time ENABLE = 5V to 0V, RL = 1k l300 ns
tOFF Turn-Off Time ENABLE = 0V to 5V, RL = 1k l85 µs
SR Slew Rate AV = –1, RL = 1k, VO = –2V to 2V l44 V/µs
LT6230-10, AV = –10, RL = 1k, VO = –2V to 2V l315 V/µs
FPBW Full-Power Bandwidth VOUT = 3VP-P (Note 9) LT6230C, LT6231C,
LT6232C
l4.66 MHz
9
623012fc
LT6230/LT6230-10
LT6231/LT6232
elecTrical characTerisTics
The l denotes the specifications which apply over the –40°C < TA < 85°C
temperature range. VS = ±5V, VCM = VOUT = 0V, ENABLE = 0V, unless otherwise noted. (Note 5)
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
VOS Input Offset Voltage LT6230I, LT6230I-10
LT6231IS8, LT6232IGN
LT6231IDD
l
l
l
700
550
650
µV
µV
µV
Input Offset Voltage Match
(Channel-to-Channel) (Note 6)
l1000 µV
VOS TC Input Offset Voltage Drift (Note 10) l0.5 3 µV/°C
IBInput Bias Current l12 µA
IB Match (Channel-to-Channel) (Note 6) l1.1 µA
IOS Input Offset Current l0.8 µA
AVOL Large-Signal Gain VO = ±4.5V, RL = 10k
VO = ±4.5V, RL = 1k
VO = ±1.5V, RL = 100Ω
l
l
l
93
25
4.8
V/mV
V/mV
V/mV
VCM Input Voltage Range Guaranteed by CMRR l–3 4 V
CMRR Common Mode Rejection Ratio VCM = –3V to 4V l95 dB
CMRR Match (Channel-to-Channel) (Note 6) VCM = –3V to 4V l89 dB
PSRR Power Supply Rejection Ratio VS = ±1.5V to ±5V l85 dB
PSRR Match (Channel-to-Channel) (Note 6) VS = ±1.5V to ±5V l79 dB
VOL Output Voltage Swing Low (Note 8) No Load
ISINK = 5mA
ISINK = 15mA
l
l
l
60
210
510
mV
mV
mV
VOH Output Voltage Swing High (Note 8) No Load
ISOURCE = 5mA
ISOURCE = 20mA
l
l
l
70
220
675
mV
mV
mV
ISC Short-Circuit Current l±15 mA
ISSupply Current per Amplifier
Disabled Supply Current per Amplifier
ENABLE = 4.8V
l
l
14.85 mA
µA
IENABLE ENABLE Pin Current ENABLE = 0.3V l–110 µA
VLENABLE Pin Input Voltage Low l0.3 V
VHENABLE Pin Input Voltage High l4.8 V
Output Leakage Current ENABLE = 4.8V, VO = ±1V l1 µA
tON Turn-On Time ENABLE = 5V to 0V, RL = 1k l300 ns
tOFF Turn-Off Time ENABLE = 0V to 5V, RL = 1k l72 µs
SR Slew Rate AV = –1, RL = 1k, VO = –2V to 2V l37 V/µs
LT6230-10, AV = –10, RL = 1k, VO = –2V to 2V l260 V/µs
FPBW Full-Power Bandwidth (Note 9) VOUT = 3VP-P; LT6230I, LT6231I, LT6232I l3.9 MHz
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2: Inputs are protected by back-to-back diodes. If the differential
input voltage exceeds 0.7V, the input current must be limited to less than
40mA.
Note 3: A heat sink may be required to keep the junction temperature
below the absolute maximum rating when the output is shorted
indefinitely.
Note 4: The LT6230C/LT6230I the LT6231C/LT6231I, and LT6232C/LT6232I
are guaranteed functional over the temperature range of –40°C and 85°C.
Note 5: The LT6230C/LT6231C/LT6232C are guaranteed to meet specified
performance from 0°C to 70°C. The LT6230C/LT6231C/LT6232C are
designed, characterized and expected to meet specified performance from
–40°C to 85°C, but are not tested or QA sampled at these temperatures.
The LT6230I/LT6231I/LT6232I are guaranteed to meet specied
performance from –40°C to 85°C.
LT6230/LT6230-10
LT6231/LT6232
10
623012fc
Note 6: Matching parameters are the difference between the two amplifiers
A and D and between B and C of the LT6232; between the two amplifiers
of the LT6231. CMRR and PSRR match are defined as follows: CMRR and
PSRR are measured in µV/V on the matched amplifiers. The difference is
calculated between the matching sides in µV/V. The result is converted to
dB.
Note 7: Minimum supply voltage is guaranteed by power supply rejection
ratio test.
elecTrical characTerisTics
Note 8: Output voltage swings are measured between the output and
power supply rails.
Note 9: Full-power bandwidth is calculated from the slew rate:
FPBW = SR/2πVP
Note 10: This parameter is not 100% tested.
Typical perForMance characTerisTics
Input Bias Current
vs Common Mode Voltage Input Bias Current vs Temperature
Output Saturation Voltage
vs Load Current (Output Low)
VOS Distribution
Supply Current vs Supply Voltage
(Per Amplifier)
Offset Voltage vs Input Common
Mode Voltage
(LT6230/LT6231/LT6232)
INPUT OFFSET VOLTAGE (µV)
–200
0
NUMBER OF UNITS
10
20
30
40
–100 0 100 200
623012 GO1
50
100
90
80
70
60
–150 –50 50 150
VS = 5V, 0V
VCM = V+/2
S8
TOTAL SUPPLY VOLTAGE (V)
0
SUPPLY CURRENT (mA)
6
623012 GO2
2 4 8
6
5
4
3
2
1
010 12 14
TA = 125°C
TA = 25°C
TA = –55°C
INPUT COMMON MODE VOLTAGE (V)
0
OFFSET VOLTAGE (mV)
1.5
623012 GO3
0.5 1 2
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0 3 4 52.5 3.5 4.5
TA = –55°C
VS = 5V, 0V
TA = 25°C
TA = 125°C
COMMON MODE VOLTAGE (V)
–1
INPUT BIAS CURRENT (µA)
2
623012 GO4
0 1 3
14
12
10
8
6
4
2
–2
0
456
TA = 125°C
TA = –55°C
TA = 25°C
VS = 5V, 0V
TEMPERATURE (°C)
–50
INPUT BIAS CURRENT (µA)
25
623012 GO5
–25 0 50
10
9
8
7
6
5
4
375 100 125
VCM = 4V
VCM = 1.5V
VS = 5V, 0V
LOAD CURRENT (mA)
0.01 0.1
0.001
OUTPUT SATURATION VOLTAGE (V)
0.01
10
1 10010
623012 GO6
0.1
1
VS = 5V, 0V
TA = –55°C
TA = 125°C
TA = 25°C
11
623012fc
LT6230/LT6230-10
LT6231/LT6232
Typical perForMance characTerisTics
Open-Loop Gain Open-Loop Gain Open-Loop Gain
Offset Voltage vs Output Current Warm-Up Drift vs Time
Total Noise vs Total Source
Resistance
Output Saturation Voltage
vs Load Current (Output High) Minimum Supply Voltage
Output Short-Circuit Current
vs Power Supply Voltage
(LT6230/LT6231/LT6232)
LOAD CURRENT (mA)
OUTPUT SATURATION VOLTAGE (V)
623012 G07
0.01 0.1
0.01
10
1 10010
0.001
0.1
1
VS = 5V, 0V
TA = –55°C
TA = 125°C
TA = 25°C
TOTAL SUPPLY VOLTAGE (V)
0
OFFSET VOLTAGE (mV)
1.5
623012 G08
0.5 1 2
1.0
0.8
0.6
0.4
0.2
0
–0.2
–0.4
–0.6
–0.8
–1.0 3 4 52.5 3.5 4.5
TA = –55°C
TA = 125°C
TA = 25°C
VCM = VS/2
POWER SUPPLY VOLTAGE (±V)
1.5
OUTPUT SHORT-CIRCUIT CURRENT (mA)
3
623012 GO9
2 2.5 3.5
70
60
40
20
50
30
10
0
–20
–40
–70
–60
–10
–30
–50
4 4.5 5
TA = 125°C
TA = –55°C
TA = –55°C
TA = 25°C
SINKING
SOURCING
TA = 25°C
TA = 125°C
OUTPUT VOLTAGE (V)
0
INPUT VOLTAGE (mV)
1.5
623012 G10
0.5 1 2
2.5
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
–2.5 32.5
RL = 100Ω
RL = 1k
VS = 3V, 0V
TA = 25°C
OUTPUT VOLTAGE (V)
0
INPUT VOLTAGE (mV)
1.5
623012 G11
0.5 1 2
0
3 4 52.5 3.5 4.5
RL = 100Ω
RL = 1k
VS = 5V, 0V
TA = 25°C
2.5
2.0
1.5
1.0
0.5
–0.5
–1.0
–1.5
–2.0
–2.5
OUTPUT VOLTAGE (V)
–5
INPUT VOLTAGE (mV)
–2
623012 G12
–4 –3 –1
0
135024
RL = 100Ω
RL = 1k
VS = ±5V
TA = 25°C
2.5
2.0
1.5
1.0
0.5
–0.5
–1.0
–1.5
–2.0
–2.5
OUTPUT CURRENT (mA)
–75
OFFSET VOLTAGE (mV)
623012 G13
–45 –15
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0 0 30 7560–60 –30 15 45
TA = –55°C
TA = 125°C
VS = ±5V
TA = 25°C
TIME AFTER POWER-UP (s)
0
CHANGE IN OFFSET VOLTAGE (µV)
60
623012 G14
20 100
30
28
24
20
16
26
22
18
14
12
10 140
40 80 120 160
TA = 25°C
VS = ±5V
VS = ±2.5V
VS = ±1.5V
SOURCE RESISTANCE (Ω)
1
TOTAL NOISE (nV/√Hz)
10
10 1k 10k 100k
623012 G15
0.1 100
100 VS = ±2.5V
VCM = 0V
f = 100kHz
UNBALANCED
SOURCE
RESISTORS
TOTAL NOISE
RESISTOR NOISE
AMPLIFIER NOISE VOLTAGE
LT6230/LT6230-10
LT6231/LT6232
12
623012fc
Typical perForMance characTerisTics
Open-Loop Gain vs Frequency
Gain Bandwidth and Phase
Margin vs Supply Voltage Slew Rate vs Temperature
Output Impedance vs Frequency
Common Mode Rejection Ratio
vs Frequency Channel Separation vs Frequency
Noise Voltage and Unbalanced
Noise Current vs Frequency
0.1Hz to 10Hz Output Voltage
Noise
Gain Bandwidth and Phase
Margin vs Temperature
(LT6230/LT6231/LT6232)
FREQUENCY (Hz)
NOISE VOLTAGE (nV/√Hz)
6
5
4
3
2
1
010 1k 10k 100k
623012 G16
100
VS = ±2.5V
TA = 25°C
VCM = 0V
NOISE VOLTAGE
NOISE CURRENT
UNBALANCED NOISE CURRENT (pA/√Hz)
6
5
4
3
2
1
0
5s/DIV
623012 G17
100nV
100nV/DIV
–100nV
VS = ±2.5V
TEMPERATURE (°C)
–55
GAIN BANDWIDTH (MHz)
5
623012 G18
–25 35
240
220
200
180
140
160
PHASE MARGIN (DEG)
70
60
50
40
65 95 125
VS = ±5V
VS = 3V, 0V
VS = ±5V
VS = 3V, 0V
PHASE MARGIN
GAIN BANDWIDTH
CL = 5pF
RL = 1k
VCM = VS/2
FREQUENCY (Hz)
GAIN (dB)
80
70
50
30
0
–10
60
40
10
20
–20
PHASE (dB)
120
100
60
20
–60
80
40
–20
–40
0
–80
100k 10M 100M 1G
623012 G19
1M
CL = 5pF
RL = 1k
VCM = VS/2
PHASE
GAIN
VS = ±5V
VS = 3V, 0V
VS = ±5V
VS = 3V, 0V
TOTAL SUPPLY VOLTAGE (V)
0
GAIN BANDWIDTH (MHz)
6
623012 G20
2 4 8
220
240
200
180
140
160
PHASE MARGIN (DEG)
70
60
50
40
10 12 14
PHASE MARGIN
GAIN BANDWIDTH
TA = 25°C
CL = 5pF
RL = 1k
TEMPERATURE (°C)
–55
SLEW RATE (V/µs)
5
623012 G21
–35 –15 45
90
100
110
120
80
70
50
20
30
60
40
8525 65 105 125
VS = ±5V FALLING
VS = ±2.5V RISING
AV = –1
RF = RG = 1k
VS = ±5V RISING
VS = ±2.5V FALLING
FREQUENCY (Hz)
1
OUTPUT IMPEDANCE (Ω)
10
100k 10M 100M
623012 G22
0.01
0.1
1M
1k
100
VS = 5V, 0V
AV = 10
AV = 1
AV = 2
FREQUENCY (Hz)
20
COMMON MODE REJECTION RATIO (dB)
40
60
80
120
100
10k 100M100k 1G10M
623012 G23
01M
VS = 5V, 0V
VCM = VS/2
FREQUENCY (Hz)
100k
CHANNEL SEPARATION (dB)
–40
–50
–60
–70
–80
–90
–100
–110
–120
–130
–140
1M 10M 100M
623012 G24
AV = 1
TA = 25°C
VS = ±5V
13
623012fc
LT6230/LT6230-10
LT6231/LT6232
Typical perForMance characTerisTics
Settling Time vs Output Step
(Noninverting)
Settling Time vs Output Step
(Inverting)
Maximum Undistorted Output
Signal vs Frequency
Distortion vs Frequency Distortion vs Frequency Distortion vs Frequency
Power Supply Rejection Ratio
vs Frequency
Series Output Resistance and
Overshoot vs Capacitive Load
Series Output Resistance and
Overshoot vs Capacitive Load
(LT6230/LT6231/LT6232)
FREQUENCY (Hz)
20
POWER SUPPLY REJECTION RATIO (dB)
40
60
80
120
100
1k 10k 100M100k 10M
623012 G25
01M
VS = 5V, 0V
TA = 25°C
VCM = VS/2
NEGATIVE SUPPLY
POSITIVE SUPPLY
CAPACITIVE LOAD (pF)
10
OVERSHOOT (%)
50
45
40
35
30
25
20
15
10
5
0100 1000
623012 G26
VS = 5V, 0V
AV = 1
RS = 10Ω
RS = 20Ω
RS = 50Ω
RL = 50Ω
CAPACITIVE LOAD (pF)
10
OVERSHOOT (%)
50
45
40
35
30
25
20
15
10
5
0100 1000
623012 G27
VS = 5V, 0V
AV = 2
RS = 10Ω
RS = 20Ω
RS = 50Ω
RL = 50Ω
OUTPUT STEP (V)
–4
SETTLING TIME (ns)
0
623012 G28
–3 –2 –1 1
100
200
150
50
0234
1mV
10mV
1mV
10mV
VS = ±5V
TA = 25°C
AV = 1
+
500Ω
VOUT
VIN
OUTPUT STEP (V)
–4
SETTLING TIME (ns)
0
623012 G29
–3 –2 –1 1
200
150
0
50
100
234
1mV
10mV
1mV
10mV
VS = ±5V
TA = 25°C
AV = –1
+
500Ω
500Ω
VOUT
VIN
FREQUENCY (Hz)
10k
OUTPUT VOLTAGE SWING (VP-P)
10
9
8
7
6
5
4
3
2
100k 1M 10M
623012 G30
VS = ±5V
TA = 25°C
HD2, HD3 < –40dBc
AV = –1
AV = 2
FREQUENCY (Hz)
10k
DISTORTION (dBc)
–40
–50
–60
–70
–80
–90
–100
100k 1M 10M
623012 G31
VS = ±2.5V
AV = 1
VOUT = 2VP-P
RL = 100Ω, 3RD
RL = 1k, 3RD
RL = 100Ω, 2ND
RL = 1k, 2ND
FREQUENCY (Hz)
10k
DISTORTION (dBc)
–40
–50
–60
–70
–80
–90
–100
100k 1M 10M
623012 G32
VS = ±5V
AV = 1
VOUT = 2VP-P
RL = 100Ω, 3RD
RL = 1k, 3RD
RL = 1k, 2ND
RL = 100Ω, 2ND
FREQUENCY (Hz)
10k
DISTORTION (dBc)
–40
–50
–60
–70
–80
–90
–100
100k 1M 10M
623012 G33
VS = ±2.5V
AV = 2
VOUT = 2VP-P RL = 100Ω, 3RD
RL = 1k, 3RD
RL = 1k, 2ND
RL = 100Ω, 2ND
LT6230/LT6230-10
LT6231/LT6232
14
623012fc
Typical perForMance characTerisTics
Distortion vs Frequency Large-Signal Response Small-Signal Response
(LT6230/LT6231/LT6232)
FREQUENCY (Hz)
10k
DISTORTION (dBc)
–40
–50
–60
–70
–80
–90
–100
100k 1M 10M
623012 G34
VS = ±5V
AV = 2
VOUT = 2VP-P
RL = 100Ω, 3RD
RL = 1k, 2ND
RL = 100Ω, 2ND
RL = 1k, 3RD
2V
0V
–2V
200ns/DIV 623012 G35
VS = ±2.5V
AV = –1
RL = 1k
1V/DIV
0V
50mV/DIV
200ns/DIV 623012 G36
VS = ±2.5V
AV = 1
RL = 1k
Large-Signal Response Output Overdrive Recovery
0V
5V
–5V
2V/DIV
200ns/DIV 623012 G37
VS = ±5V
AV = 1
RL = 1k
0V
0V
VIN
1V/DIV
VOUT
2V/DIV
200ns/DIV 623012 G38
VS = ±2.5V
AV = 3
(LT6230) ENABLE Characteristics
Supply Current
vs ENABLE Pin Voltage
ENABLE Pin Current
vs ENABLE Pin Voltage ENABLE Pin Response Time
PIN VOLTAGE (V)
SUPPLY CURRENT (mA)
–1.0
623012 G39
–2.0 0
4.5
4.0
3.5
3.0
2.5
2.0
1.0
0.5
1.5
01.0 2.0
VS = ±2.5V
TA = 125°C
TA = 25°C
TA = –55°C
PIN VOLTAGE (V)
ENABLE PIN CURRENT (µA)
623012 G40
30
25
20
15
10
5
0
TA = 125°C
VS = ±2.5V
AV = 1
TA = 25°C
TA = –55°C
–1.0
–2.0 0 1.0 2.0
0.5V
0V
0V
5V
ENABLE PIN
VOUT
100µs/DIV 623012 G41
VS = ±2.5V
VIN = 0.5V
AV = 1
RL = 1k
15
623012fc
LT6230/LT6230-10
LT6231/LT6232
Typical perForMance characTerisTics
Open-Loop Gain and Phase
vs Frequency
Gain Bandwidth and Phase
Margin vs Supply Voltage Gain Bandwidth vs Resistor Load
Common Mode Rejection Ratio
vs Frequency
Maximum Undistorted Output
Signal vs Frequency
2nd and 3rd Harmonic Distortion
vs Frequency
Gain Bandwidth and Phase
Margin vs Temperature Slew Rate vs Temperature
Series Output Resistor and
Overshoot vs Capacitive Load
(LT6230-10)
TEMPERATURE (°C)
–50
GAIN BANDWIDTH (MHz)
25
623012 G42
–25 0 50
1700
1500
1300
1100
900
PHASE MARGIN (DEG)
70
80
60
50
40
75 100 125
VS = ±5V
VS = 3V, 0V
VS = ±5V
VS = 3V, 0V
PHASE MARGIN
GAIN BANDWIDTH
AV = 10
TEMPERATURE (°C)
–55
SLEW RATE (V/µs)
5
623012 G43
–35 –15 45
450
500
550
600
400
350
250
100
150
300
200
8525 65 105 125
VS = ±5V FALLING
VS = ±2.5V RISING
AV = –10
RF = 1k
RG = 100W
VS = ±5V RISING
VS = ±2.5V FALLING
CAPACITIVE LOAD (pF)
10
OVERSHOOT (%)
70
60
50
40
30
20
10
0
100 1000 10000
623012 G44
VS = 5V, 0V
AV = 10
RS = 10Ω
RS = 20Ω
RS = 50Ω
FREQUENCY (Hz)
GAIN (dB)
90
80
70
60
50
40
30
20
10
0
–10
PHASE (DEG)
120
100
80
60
40
20
0
–20
–40
–60
–80
100k 10M 100M 1G
623012 G45
1M
AV = 10
CL = 5pF
RL = 1k
VCM = VS/2
VS = 3V, 0V
VS = ±5V
PHASE
GAIN
VS = ±5V
VS = 3V, 0V
TOTAL SUPPLY VOLTAGE (V)
0
GAIN BANDWIDTH (MHz)
6
623012 G46
2 4 8
1700
1450
1200
950
PHASE MARGIN (DEG)
100
50
0
10 12
PHASE MARGIN
GAIN BANDWIDTH
TA = 25°C
AV = 10
CL = 5pF
RL = 1k
TOTAL RESISTOR LOAD (Ω)
(INCLUDES FEEDBACK R)
0
GAIN BANDWIDTH (MHz)
600
623012 G47
200 400 800
1600
1400
1200
800
600
400
200
0
1000
1000
AV = 10
VS = ±5V
TA = 25°C
RF = 1k
RG = 100
FREQUENCY (Hz)
20
COMMON MODE REJECTION RATIO (dB)
40
60
80
120
100
10k 1G100M100k 10M
623012 G48
01M
VS = 5V, 0V
VCM = VS/2
FREQUENCY (Hz)
10k
OUTPUT VOLTAGE SWING (VP-P)
10
9
8
7
6
5
4
3
2
1
0
100k 1M 100M10M
623012 G49
VS = ±5V
TA = 25°C
AV = 10
HD2 = HD3 ≤ 40dBc
FREQUENCY (Hz)
10k
DISTORTION (dBc)
–40
–50
–60
–70
–80
–90
–100
100k 1M 10M
623012 G50
VS = ±2.5V
AV = 10
VOUT = 2VP-P
RL = 100Ω, 3RD
RL = 100Ω, 2ND
RL = 1k, 3RD
RL = 1k, 2ND
LT6230/LT6230-10
LT6231/LT6232
16
623012fc
Typical perForMance characTerisTics
2nd and 3rd Harmonic Distortion
vs Frequency Large-Signal Response Output-Overload Recovery
(LT6230-10)
FREQUENCY (Hz)
10k
DISTORTION (dBc)
–40
–50
–60
–70
–80
–90
–100
100k 1M 10M
623012 G51
VS = ±5V
AV = 10
VOUT = 2VP-P
RL = 100Ω, 3RD
RL = 100Ω, 2ND
RL = 1k, 2ND
RL = 1k, 3RD
0V
VOUT
2V/DIV
100ns/DIV 623012 G52
VS = ±5V
AV = 10
RF = 900Ω
RG = 100Ω
0V
0V
VOUT
2V/DIV
VIN
0.5V/DIV
100ns/DIV 623012 G53
VS = 5V, 0V
AV = 10
RF = 900Ω
RG = 100Ω
Small-Signal Response
Input Referred High Frequency
Noise Spectrum
2.5V
VOUT
100mV/DIV
100ns/DIV 623012 G54
VS = 5V, 0V
AV = 10
RF = 900Ω
RG = 100Ω
10
0
1nV/√Hz/DIV
5MHz/DIV 623012 G55
100kHz 50MHz
17
623012fc
LT6230/LT6230-10
LT6231/LT6232
applicaTions inForMaTion
Amplifier Characteristics
Figure 1 is a simplified schematic of the LT6230/LT6231/
LT6232, which has a pair of low noise input transistors
Q1 and Q2. A simple current mirror, Q3/Q4, converts the
differential signal to a single-ended output, and these
transistors are degenerated to reduce their contribution
to the overall noise.
Capacitor C1 reduces the unity-cross frequency and im-
proves the frequency stability without degrading the gain
bandwidth of the amplifier. Capacitor CM sets the overall
amplifier gain bandwidth. The differential drive generator
supplies current to transistors Q5 and Q6 that swing the
output from rail-to-rail.
Input Protection
There are back-to-back diodes, D1 and D2 across the + and
– inputs of these amplifiers to limit the differential input
voltage to ±0.7V. The inputs of the LT6230/LT6231/LT6232
do not have internal resistors in series with the input tran-
sistors. This technique is often used to protect the input
devices from overvoltage that causes excessive current
to flow. The addition of these resistors would significantly
degrade the low noise voltage of these amplifiers. For
instance, a 100Ω resistor in series with each input would
generate 1.8nV/√Hz of noise, and the total amplifier noise
voltage would rise from 1.1nV/√Hz to 2.1nV/√Hz. Once
the input differential voltage exceeds ±0.7V, steady-state
current conducted through the protection diodes should
be limited to ±40mA. This implies 25Ω of protection re-
sistance is necessary per volt of overdrive beyond ±0.7V.
These input diodes are rugged enough to handle transient
currents due to amplifier slew rate overdrive and clipping
without protection resistors.
The photo of Figure 2 shows the output response to an
input overdrive with the amplifier connected as a voltage
follower. With the input signal low, current source I1 satu-
rates and the differential drive generator drives Q6 into
saturation so the output voltage swings all the way to V.
The input can swing positive until transistor Q2 saturates
into current mirror Q3/Q4. When saturation occurs, the
output tries to phase invert, but diode D2 conducts current
from the signal source to the output through the feedback
connection. The output is clamped a diode drop below the
input. In this photo, the input signal generator is limiting
at about 20mA.
ENABLE
DESD6
DESD5
–V
+V
+VIN
–VIN +V
623012 F01
BIAS
DIFFERENTIAL
DRIVE GENERATOR
VOUT
+V
CM
I1
–V
DESD3
–V
–V
DESD4
+V
DESD1
–V
DESD2
+V
D1
C1
D2
Q5
Q6
Q4
Q2
Q3
Q1
2.5V
0V
–2.5V
500µs/DIV 623012 F02
1V/DIV
Figure 1. Simplified Schematic
Figure 2. VS = ±2.5V, AV = 1 with Large Overdrive
LT6230/LT6230-10
LT6231/LT6232
18
623012fc
With the amplifier connected in a gain of AV ≥ 2, the output
can invert with very heavy overdrive. To avoid this inver-
sion, limit the input overdrive to 0.5V beyond the power
supply rails.
ESD
The LT6230/LT6231/LT6232 have reverse-biased ESD
protection diodes on all inputs and outputs as shown in
Figure 1. If these pins are forced beyond either supply,
unlimited current will ow through these diodes. If the
current is transient and limited to one hundred milliamps
or less, no damage to the device will occur.
Noise
The noise voltage of the LT6230/LT6231/LT6232 is equiva-
lent to that of a 75Ω resistor, and for the lowest possible
noise it is desirable to keep the source and feedback resis-
tance at or below this value, i.e., RS + RG||RFB ≤ 75Ω. With
RS + RG||RFB = 75Ω the total noise of the amplifier is:
eN=√(1.1nV)2+(1.1nV)2 = 1.55nV/√Hz
Below this resistance value, the amplifier dominates the
noise, but in the region between 75Ω and about 3k, the
noise is dominated by the resistor thermal noise. As the
total resistance is further increased beyond 3k, the amplifier
noise current multiplied by the total resistance eventually
dominates the noise.
The product of eN √ISUPPLY is an interesting way to
gauge low noise amplifiers. Most low noise amplifiers
with low eN have high ISUPPLY current. In applications that
require low noise voltage with the lowest possible supply
current, this product can prove to be enlightening. The
LT6230/LT6231/LT6232 have an eN • √ISUPPLY product of
only 1.9 per amplifier, yet it is common to see amplifiers
with similar noise specifications to have eN • √ISUPPLY as
high as 13.5.
For a complete discussion of amplifier noise, see the
LT1028 data sheet.
ENABLE Pin
The LT6230 includes an ENABLE pin that shuts down the
amplifier to 10µA maximum supply current. The ENABLE
pin must be driven low to operate the amplifier with normal
supply current. The ENABLE pin must be driven high to
within 0.35V of V+ to shut down the supply current. This
can be accomplished with simple gate logic; however
care must be taken if the logic and the LT6230 operate
from different supplies. If this is the case, then open-drain
logic can be used with a pull-up resistor to ensure that
the amplifier remains off. See the Typical Performance
Characteristics.
The output leakage current when disabled is very low;
however, current can flow into the input protection diodes
D1 and D2 if the output voltage exceeds the input voltage
by a diode drop.
applicaTions inForMaTion
19
623012fc
LT6230/LT6230-10
LT6231/LT6232
Typical applicaTions
Single Supply, Low Noise, Low Power, Bandpass Filter with Gain = 10
Frequency Response Plot of
Bandpass Filter
Low Noise, Low Power, Single Supply, Instrumentation Amplifier with Gain = 100
+
R2
732Ω
R4
10k
C3
0.1µF
EN
LT6230
f0 = 1 = 1MHz
C = √C1C2, R = R1 = R2
f0 =
(
732Ω
)
MHz, MAXIMUM f0 = 1MHz
f–3dB =
f0
AV = 20dB at f0
EN = 4µVRMS INPUT REFERRED
IS = 3.7mA FOR V+ = 5V
623012 F03
0.1µF
C2
47pF
C1
1000pF R3
10k
R1
732Ω
VOUT
V+
VIN
2πRC
R
2.5
FREQUENCY (Hz)
100k
GAIN (dB)
23
3
–7 1M 10M
623012 F04
+
R14
2k
EN
U3
LT6230
VOUT = 100 (VIN2 – VIN1)
GAIN =
(
R2 + 1
)
(
R10
)
INPUT RESISTANCE = R5 = R6
f–3dB = 310Hz TO 11MHz
EN = 20µVRMS INPUT REFERRED
IS = 10.5mA FOR VS = 5V, 0V 623012 F05
C8
68pF
C3
1µF
R13
2k
R10
511Ω
R15
88.7Ω
R16
88.7Ω
R4
511Ω
R3
30.9Ω
R1
30.9Ω
R2
511Ω
VOUT
VIN1
VIN2
V+
R1 R15
C9
68pF
R12
511Ω
+
EN
U2
LT6230-10
V+
C1
1µF
C2
2200pF
+
EN
U1
LT6230-10
V+
R5
511Ω
R6
511Ω
C4
10µF
R1 = R3
R2 = R4
R10 = R12
R15 = R16
LT6230/LT6230-10
LT6231/LT6232
20
623012fc
package DescripTion
S6 Package
6-Lead Plastic TSOT-23
(Reference LTC DWG # 05-08-1636)
1.50 – 1.75
(NOTE 4)
2.80 BSC
0.30 – 0.45
6 PLCS (NOTE 3)
DATUM ‘A
0.09 – 0.20
(NOTE 3) S6 TSOT-23 0302 REV B
2.90 BSC
(NOTE 4)
0.95 BSC
1.90 BSC
0.80 – 0.90
1.00 MAX 0.01 – 0.10
0.20 BSC
0.30 – 0.50 REF
PIN ONE ID
NOTE:
1. DIMENSIONS ARE IN MILLIMETERS
2. DRAWING NOT TO SCALE
3. DIMENSIONS ARE INCLUSIVE OF PLATING
4. DIMENSIONS ARE EXCLUSIVE OF MOLD FLASH AND METAL BURR
5. MOLD FLASH SHALL NOT EXCEED 0.254mm
6. JEDEC PACKAGE REFERENCE IS MO-193
3.85 MAX
0.62
MAX
0.95
REF
RECOMMENDED SOLDER PAD LAYOUT
PER IPC CALCULATOR
1.4 MIN
2.62 REF
1.22 REF
21
623012fc
LT6230/LT6230-10
LT6231/LT6232
package DescripTion
DD Package
8-Lead Plastic DFN (3mm × 3mm)
(Reference LTC DWG # 05-08-1698 Rev C)
3.00 ±0.10
(4 SIDES)
NOTE:
1. DRAWING TO BE MADE A JEDEC PACKAGE OUTLINE M0-229 VARIATION OF (WEED-1)
2. DRAWING NOT TO SCALE
3. ALL DIMENSIONS ARE IN MILLIMETERS
4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE
MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.15mm ON ANY SIDE
5. EXPOSED PAD SHALL BE SOLDER PLATED
6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION
ON TOP AND BOTTOM OF PACKAGE
0.40 ± 0.10
BOTTOM VIEW—EXPOSED PAD
1.65 ± 0.10
(2 SIDES)
0.75 ±0.05
R = 0.125
TYP
2.38 ±0.10
14
85
PIN 1
TOP MARK
(NOTE 6)
0.200 REF
0.00 – 0.05
(DD8) DFN 0509 REV C
0.25 ± 0.05
2.38 ±0.05
RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS
APPLY SOLDER MASK TO AREAS THAT ARE NOT SOLDERED
1.65 ±0.05
(2 SIDES)2.10 ±0.05
0.50
BSC
0.70 ±0.05
3.5 ±0.05
PACKAGE
OUTLINE
0.25 ± 0.05
0.50 BSC
LT6230/LT6230-10
LT6231/LT6232
22
623012fc
package DescripTion
S8 Package
8-Lead Plastic Small Outline (Narrow .150 Inch)
(Reference LTC DWG # 05-08-1610)
.016 – .050
(0.406 – 1.270)
.010 – .020
(0.254 – 0.508)× 45°
0°– 8° TYP
.008 – .010
(0.203 – 0.254)
SO8 0303
.053 – .069
(1.346 – 1.752)
.014 – .019
(0.355 – 0.483)
TYP
.004 – .010
(0.101 – 0.254)
.050
(1.270)
BSC
1234
.150 – .157
(3.810 – 3.988)
NOTE 3
8765
.189 – .197
(4.801 – 5.004)
NOTE 3
.228 – .244
(5.791 – 6.197)
.245
MIN .160 ±.005
RECOMMENDED SOLDER PAD LAYOUT
.045 ±.005
.050 BSC
.030 ±.005
TYP
INCHES
(MILLIMETERS)
NOTE:
1. DIMENSIONS IN
2. DRAWING NOT TO SCALE
3. THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .006" (0.15mm)
GN Package
16-Lead Plastic SSOP (Narrow .150 Inch)
(Reference LTC DWG # 05-08-1641)
GN16 (SSOP) 0204
1 2 345678
.229 – .244
(5.817 – 6.198)
.150 – .157**
(3.810 – 3.988)
16 15 14 13
.189 – .196*
(4.801 – 4.978)
12 11 10 9
.016 – .050
(0.406 – 1.270)
.015 ± .004
(0.38 ± 0.10) × 45°
0° – 8° TYP
.007 – .0098
(0.178 – 0.249)
.0532 – .0688
(1.35 – 1.75)
.008 – .012
(0.203 – 0.305)
TYP
.004 – .0098
(0.102 – 0.249)
.0250
(0.635)
BSC
.009
(0.229)
REF
.254 MIN
RECOMMENDED SOLDER PAD LAYOUT
.150 – .165
.0250 BSC.0165 ±.0015
.045 ±.005
* DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH
SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE
** DIMENSION DOES NOT INCLUDE INTERLEAD FLASH. INTERLEAD
FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE
INCHES
(MILLIMETERS)
NOTE:
1. CONTROLLING DIMENSION: INCHES
2. DIMENSIONS ARE IN
3. DRAWING NOT TO SCALE
23
623012fc
LT6230/LT6230-10
LT6231/LT6232
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa-
tion that the interconnection of its circuits as described herein will not infringe on existing patent rights.
revision hisTory
REV DATE DESCRIPTION PAGE NUMBER
C 1/11 Updated ENABLE Pin section in Applications Information 18
(Revision history begins at Rev C)
LT6230/LT6230-10
LT6231/LT6232
24
623012fc
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 FAX: (408) 434-0507 www.linear.com
LINEAR TECHNOLOGY CORPORATION 2003
LT 0111 REV C • PRINTED IN USA
relaTeD parTs
Typical applicaTions
The LT6230 is applied as a transimpedance amplifier with
an I-to-V conversion gain of 1.5kΩ set by R1. The LT6230
is ideally suited to this application because of its low
input offset voltage and current, and its low noise. This is
because the 1.5k resistor has an inherent thermal noise
of 5nV/√Hz or 3.4pA/√Hz at room temperature, while the
LT6230 contributes only 1.1nV and 2.4pA /√Hz. So, with
respect to both voltage and current noises, the LT6230 is
actually quieter than the gain resistor.
The circuit uses an avalanche photodiode with the cathode
biased to approximately 200V. When light is incident on
the photodiode, it induces a current IPD which flows into
the amplifier circuit. The amplifier output falls negative
to maintain balance at its inputs. The transfer function
is therefore VOUT = –IPD 1.5k. C1 ensures stability and
good settling characteristics. Output offset was measured
at 280µV, so low in part because R2 serves to cancel the
DC effects of bias current. Output noise was measured
at 1.1mVP-P on a 100MHz measurement bandwidth, with
C2 shunting R2’s thermal noise. As shown in the scope
photo, the rise time is 17ns, indicating a signal bandwidth
of 20MHz.
Low Power Avalanche Photodiode Transimpedance Amplifier
IS = 3.3mA
+
R1
1.5k
R2
1.5k
C2
0.1µF
5V
–5V
ENABLE
LT6230
≈200V BIAS
ADVANCED PHOTONIX
012-70-62-541
WWW.ADVANCEDPHOTONIX.COM
623012 TA02a
C1
4.7pF
OUTPUT OFFSET = 500µV TYPICAL
BANDWIDTH = 20MHz
OUTPUT NOISE = 1.1mVP-P (100MHz MEASUREMENT BW)
Photodiode Amplifier Time Domain Response
50ns/DIV 623012 TA02b
30mV/DIV
PART NUMBER DESCRIPTION COMMENTS
LT1028 Single, Ultralow Noise 50MHz Op Amp 0.85nV/√Hz
LT1677 Single, Low Noise Rail-to-Rail Amplifier 3V Operation, 2.5mA, 4.5nV/√Hz, 60µV Max VOS
LT1806/LT1807 Single/Dual, Low Noise 325MHz Rail-to-Rail Amplifier 2.5V Operation, 550µV Max VOS, 3.5nV/√Hz
LT6200/LT6201 Single/Dual, Low Noise 165MHz 0.95nV√Hz, Rail-to-Rail Input and Output
LT6202/LT6203/LT6204 Single/Dual/Quad, Low Noise, Rail-to-Rail Amplifier 1.9nV/√Hz, 3mA Max, 100MHz Gain Bandwidth