1/11February 2003
■ OUTPUT CURRENT UP TO 200mA
■LOW DROP O UT VOLTAGE (500mV MAX AT
IOUT=200mA)
■VERY LOW QUIESCENT CURRENT: 0.1µA
IN OFF MODE AND MAX 250µA IN ON
MODE AT IOUT=0mA
■LOW OUTPUT NOISE: TYP 30µV AT
IOUT= 60m A AND 10Hz<f<80KHz
■WIDE RANGE OF OUTPUT VO LTA GES
■INTERNAL CURRENT AND THERMAL LIMIT
■VOUT TOLERANCE ± 2% (AT 25°C)
DESCRIPTION
The L K1 12S is a low d ropout linear regul ato r with
a built in electroni c switch. The internal switch can
be controlled by TTL or CMOS logic levels. The
device is ON st ate when the control pi n is pulled to
a logic high level. An external capacitor can be
used connected to the noise bypass pin to lower
the output noise l evel to 30µVrms. An internal PNP
pass transistor is used to achieve a low dropout
voltage.
The LK112S has a very low quiescent current in
ON MODE while in OFF MODE the Iq is reduced
down to 100nA max. The internal thermal
shut down c ircuitry limits the juntion temperature to
below 150°C. The load current is internally
monitored and the device will shutdown in the
pres ence of a short circuit or over current condit ion
at t he output.
LK112S
SERIES
LOW NOISE LOW DROP VOLTAGE REGULATOR
WI TH S HU T D OWN FUNCTI ON
SCHEMATIC DIAGRAM
SOT23-5L
LK112S SERIES
2/11
ABSOLUTE MAXIMUM RATINGS
CONNECTION DIAGRAM (top view) PIN DESCRIPTION
ELECTRICAL CHARACTERISTICS FOR LK112 (Tj = 25°C, VIN=VOUT+1V (see Note 1), IOUT=0mA,
VSHDN=1.8V, CI = 1 µF, CO = 2 . 2µF, CBYPASS = 0.1µF unless otherwise specifie d)
Note 1: for version with output vo l t age less than 2V VIN=2.4V
Note 2: only fo r version with output voltage more than 2.1V
Symbol Parameter² Value Unit
VIDC Input Voltage 16 V
VSHDN Shutdown Input Voltage 16 V
IOOutput Current Internally limited
Tstg Storage Temperature Range -55 to +150 °C
Top Operating Junction Temperature Range -30 to +80 °C
SOT23-5L
Pin N° Symbol Name and Function
1 SHDN Shutdown Input: Disables the
regulator when is connected to GND
or to positive voltage less t han 0.6V
2 GND Ground Pin: Internally connected to
the die attach flag to decrease the
total thermal resistance and increase
the package ability to dissipate
power.
3 Bypass Bypass Pin: Bypass with 0.1µF to
improve the Vref thermal noise
performances.
4 OUT Output Port
5 IN Input Port
Symbol Parameter Test Conditions Min. Typ. Max. Unit
IdQuiescent Current ON MODE (except ISHDN) 175 250 µA
OFF MODE VI = 8V VSHDN = 0V 0 0.1 µA
VOOutput Voltage IO = 30mA (see table)
∆VOLine Regulation VI = VO+1V to VO+6V, VO ≤ 5.6V 0.7 20 mV
VI = VO+1V to VO+6V, VO > 5.6V 0.8 40 mV
∆VOLoad Regulation IO = 1 to 60mA 15 30 mV
IO = 1 to 200mA 30 90 mV
VdDropout Voltage IO = 60 mA (see Note 2) 0.17 0.24 V
IO = 200 mA (see Note 2) 0.35 0.5 V
ISC Short Circuit Current 200 mA
SVR Supply Voltage Rejection VI = VO+1.5V CBYP = 0.1µF
CO = 10µF f = 400Hz IO = 30mA 55 dB
eN Output Noise Voltage B= 10Hz to 80KHz CBYP = 0.1µF
CO = 10µFV
I
= VO+1.5V,IO = 60mA 30 µVrms
ISHDN Shutdown Input Current VSHDN = 1.8V Output ON 12 35 µA
VSHDN Shutdown Input Logic Output ON
Output OFF 1.8 0.6 V
V
∆VO/TjOutput Voltage
Temperature Coefficient IO = 10mA 0.09 mV/° C
LK112S SERIES
3/11
ORDERING NUMBERS AND OUTPUT VOLTAGE
(* ) A vailabl e o n request
Part Number Output Voltage VOUT Min VOUT Max Test Voltage
LK112SM13TR 1.3V 1.24V 1.36V 2.4V
LK112SM14TR (*) 1.4V 1.34V 1.46V 2.4V
LK112SM15TR 1.5V 1.44V 1.56V 2.4V
LK112SM16TR 1.6V 1.54V 1.66V 2.4V
LK112SM17TR (*) 1.7V 1.64V 1.76V 2.4V
LK112SM18TR 1.8V 1.74V 1.86V 2.4V
LK112SM19TR (*) 1.9V 1.84V 1.96V 2.4V
LK112SM20TR (*) 2.0V 1.94V 2.06V 3.0V
LK112SM21TR 2.1V 2.04V 2.16V 3.1V
LK112SM22TR (*) 2.2V 2.14V 2.26V 3.2V
LK112SM23TR (*) 2.3V 2.24V 2.36V 3.3V
LK112SM24TR (*) 2.4V 2.34V 2.46V 3.4V
LK112SM25TR 2.5V 2.44V 2.56V 3.5V
LK112SM26TR (*) 2.6V 2.54V 2.66V 3.6V
LK112SM27TR (*) 2.7V 2.64V 2.76V 3.7V
LK112SM28TR 2.8V 2.74V 2.86V 3.8V
LK112SM29TR (*) 2.9V 2.84V 2.96V 3.9V
LK112SM30TR 3.0V 2.94V 3.06V 4.0V
LK112SM31TR (*) 3.1V 3.04V 3.16V 4.1V
LK112SM32TR 3.2V 3.14V 3.26V 4.2V
LK112SM33TR 3.3V 3.24V 3.36V 4.3V
LK112SM34TR (*) 3.4V 3.335V 3.465V 4.4V
LK112SM35TR (*) 3.5V 3.435V 3.565V 4.5V
LK112SM36TR 3.6V 3.535V 3.655V 4.6V
LK112SM37TR (*) 3.7V 3.630V 3.770V 4.7V
LK112SM38TR 3.8V 3.725V 3.875V 4.8V
LK112SM39TR (*) 3.9V 3.825V 3.975V 4.9V
LK112SM40TR 4.0V 3.920V 4.080V 5.0V
LK112SM41TR (*) 4.1V 4.020V 4.180V 5.1V
LK112SM42TR (*) 4.2V 4.120V 4.280V 5.2V
LK112SM43TR (*) 4.3V 4.215V 4.385V 5.3V
LK112SM44TR (*) 4.4V 4.315V 4.485V 5.4V
LK112SM45TR (*) 4.5V 4.410V 4.590V 5.5V
LK112SM46TR (*) 4.6V 4.510V 4.690V 5.6V
LK112SM47TR 4.7V 4.605V 4.795V 5.7V
LK112SM48TR (*) 4.8V 4.705V 4.895V 5.8V
LK112SM49TR (*) 4.9V 4.800V 5.000V 5.9V
LK112SM50TR 5.0V 4.900V 5.100V 6.0V
LK112SM55TR (*) 5.5V 5.390V 5.610V 6.5V
LK112M60TR 6.0V 5.880V 6.120V 7.0V
LK112SM80TR 8.0V 7.840V 8.160V 9.0V
LK112S SERIES
4/11
TYPICAL CHARACTERI STICS (unless otherwise specified Tj = 25°C, CI=1µF, CO=2.2µF, CBYP=100nF)
Fi gure 1 : Output Voltage vs Temp erature
Fi gure 2 : Output Voltage vs Temp erature
Fi gure 3 : Line Regulation vs Temperature
Fi gure 4 : Load Regulation vs Temperature
Fi gure 5 : Dropout Voltage vs Temperature
Fi gure 6 : Short Circuit Currennt vs Dropout
Volt age
LK112S SERIES
5/11
Fi gure 7 : Output Voltage vs Input Voltage
Fi gure 8 : Shutdown Voltage vs Temperature
Fi gure 9 : Shutdown Current vs Shutdown
Volt age
Fi gure 10 : Supply Voltage Rejection vs
Temperature
Fi gure 11 : Supply Volt age Rej ection vs Output
Current
Fi gure 12 : Supply Voltage Rejection vs
Frequency
LK112S SERIES
6/11
Fi gure 13 : Supply Voltage Rejection vs
Temperature
Fi gure 14 : Quiescent Current vs Temperature
Fi gure 15 : Quiescent Current vs Input Voltage
Fi gure 16 : Quiescent Current vs Shutdown
Volt age
Fi gure 17 : Quiescent Current vs Output C urrent
Fi gure 18 : Reverse Current vs Reverse Voltage
LK112S SERIES
7/11
Fi gure 19 : Stability
Fi gure 20 : Spectrum Noi se
Fi gure 21 : Start-up Transient
Fi gure 22 : Start-up Transient
Fi gure 23 : Line Transient
Fi gure 24 : Line Transient
V
I=
3
.5
V
,
V
O=
2
.5
V
,
V
SHDN=
0
to
1
.
8V
,
R
L=
2
.5
K
Ω,
C
I=
1
µ
F
,
CO=4.7µF, CBY=10nF
V
I=
3
.5
V
,
V
O=
2
.5
V
,
V
SHDN=
0
to
1
.
8V
,
R
L=
68
Ω,
C
I=
1
µ
F
,
C
O=
4
.7µ
F
,
CBY=100nF
V
I=
3
.5 t o
4
.5
V
,
V
O=
2
.5
V
,
V
SHDN=
1
.
8V
,
I
O=
30
m
A
,
N
o
C
I,
C
O=
10
µ
F
,
CBY=100nF, t s=tf=2µs
V
I=
3
.5 t o
4
.5
V
,
V
O=
2
.5
V
,
V
SHDN=
1
.
8V
,
I
O=
30
m
A
,
N
o
C
I,
C
O=
10
µ
F
,
CBY=10nF, ts=tf=2µs
LK112S SERIES
8/11
Fi gure 25 : Line Transient
Fi gure 26 : Load Transient
Fi gure 27 : Load Transient
Fi gure 28 : Load Transient
V
I=
3
.5 to
4
.5
V
,
V
O=
2
.5
V
,
V
SHDN=
1
.
8V
,
I
O=
30
m
A
,
N
o
C
I,
C
O=
1
µ
F
,
CBY=1nF, t s=tf=2µs
V
I=
3
.
5
V
,
V
O=
2
.
5V
,
V
SHDN=
1
.
8V
,
I
O=
50
t
o
100
m
A
,
C
I=
1
µ
F
,
CO=2.2µF, CBY=10nF, ts=tf=250ns
V
I=
3
.5
V
,
V
O=
2
.5
V
,
V
SHDN=
1
.
8V
,
I
O=5
0
to
100
m
A
,
C
I
1
µ
F
,
CO=10µF, CBY=1 00nF, ts=tf=250ns
V
I=
4
.
8
V
,
V
O=
3
.
8V
,
V
SHDN=
1
.
8V
,
I
O=
50
t
o
100
m
A
,
C
I=
1
µ
F
,
CO=2.2µF, CBY=10nF, ts=tf=250ns
LK112S SERIES
9/11
DIM. mm. mils
MIN. TYP MAX. MIN. TYP. MAX.
A 0.90 1.45 35.4 57.1
A1 0.00 0.15 0.0 5.9
A2 0.90 1.30 35.4 51.2
b 0.35 0.50 13.7 19.7
C 0.09 0.20 3.5 7.8
D 2.80 3.00 110.2 118.1
E 2.60 3.00 102.3 118.1
E1 1.50 1.75 59.0 68.8
e.95 37.4
e1 1.9 74.8
L 0.35 0.55 13.7 21.6
SOT23-5L MECHANICAL DATA
0
LK112S SERIES
10/11
DIM. mm. inch
MIN. TYP MAX. MIN. TYP. MAX.
A 180 7.086
C 12.8 13.0 13.2 0.504 0.512 0.519
D 20.2 0.795
N 60 2.362
T 14.4 0.567
Ao 3.13 3.23 3.33 0.123 0.127 0.131
Bo 3.07 3.17 3.27 0.120 0.124 0.128
Ko 1.27 1.37 1.47 0.050 0.054 0.0.58
Po 3.9 4.0 4.1 0.153 0.157 0.161
P 3.9 4.0 4.1 0.153 0.157 0.161
Tape & Reel SOT23-xL MECHANICAL DATA
LK112S SERIES
11/11
Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the
conseq uences of u se of such inform ation nor for any in fring ement of p atents or o ther ri ghts of th ird p arties which may r esul t f rom
its use. No license is granted by implication or otherwise under any patent or patent rights of STMicroelectronics. Specifications
mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information
previously supplied. STMicroelectronics products are not authorized for use as critical components in life support devices or
systems without express written approval of STMicroelectronics.
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