EM6415
Copyright 2002, EM Microelectronic-Marin SA 1 www.emmicroelectronic.com
Sensor Signal Conditioner Circuit with 14 bits A/D Converter
Description
The EM6415 is a high resolution A/D converter in low
voltage CMOS technology intended to be used as a
programmable link between one to four resistive sensors
and a microcontroller.
There is no need of external components for calibration,
error curve compensation or offset and gain adjustment,
nor external amplifiers and sensor bridge drive circuits.
After exposure to a calibration signal/profile, all
conversion parameters and profile coefficients are self
calculated and stored in an external EEPROM.
In addition to a programmable dual slope 10/13/14 bit A/D
conversion, EM6415 allows individual compensation of
not only sensor offset and full scale errors, but also
temperature error compensation of the sensor zero point
and sensitivity, dynamically during the conversion
process. EM6415 also contains a programmable sensor
drive current source.
Features
Full sensor system on chip
Four sensor channel multiplexer
Programmable Dual slope A/D converter
Program selectable 10, 13 or 14 bit resolution
ADC resolves 1µV/Bit
Programmable sensor offset, gain and linearity
High flexibility in zero adjust and full scale adjust
Sensor error compensation performed by software
Parallel 4 bit microcontroller interface
Self calibration of conversion parameters and profile
coefficients
Ultra low noise differential input amplifier with mask
programmable gain
Excellent linearity over full transfer curve
Programmable current source for sensor supplies.
Low supply voltage range 2.2V – 3.6 V
Low operation current, 240 µA at 800 kHz, 3V
Ultra low power consumption (at standby or after
conversion down to less than 0.1 µA)
Small SSOP36-300mils package
Applications
Portable sensor instruments
Telemetry
Resistive sensor interfaces
Automotive sensors
Industrial process control
Consumer instruments
Typical Application
Fig. 1
EM MICROELECTRONIC - MARIN SA
EM6415
MICROCONTROLLER
STROBE
WR
RD
CE
EEPROM
DATA
LCD
VSSD VSSA VREF
D0-D3
CAZ CI
CINT
RINT10
RINT13_14
P3WAY
AZN
VDD
VDDDVDDA
RSEN1
RSEN2
Sensor1
TS1
CH1H
CH1L
Sensor4
TS4
CH4H
CH4L
TS2
CH2H
CH2L
TS3
CH3H
CH3L
Sensor2
Sensor3
CLKP
CLKSEL
VDD
CE
RD
WR
ALE
EM6415
Copyright 2002, EM Microelectronic-Marin SA 2 www.emmicroelectronic.com
Block Diagram
Fig. 2
Programmable
Current Source
RSEN1 RSEN2
Analog
Multiplexer
4- Power On
Reset
Detector
Microcontroller Interface
and Control Logic
CE ALE WR RD D3 D2 D1 D0
DC Bias
RC
Oscillator
10 / 13 / 14 Bit
Dual Slope
AD Converter
AZN P3WAY CINT
Fixed Gain Amplifier
8 Bit
D/A Converter
Offset + Full Scale
Calibration
CH1
CH2
CH3
CH4
RINT13_14VREF
Bandgap
Voltage
Reference
TS1
CH1H
CH1L
TS2
CH2H
CH2L
TS3
CH3H
CH3L
TS4
CH4H
CH4L
CLKSEL
CLKP
4-Bit D/A
Converter
EM6415
Copyright 2002, EM Microelectronic-Marin SA 3 www.emmicroelectronic.com
Absolute Maximum Ratings
Parameter Symbol Min Max Unit
Supply Voltage
Voltage at
remaining pins
Storage
temperature
Operating
temperature
Soldering
Temperature*Time
VDD
VPIN
Tstore
Top
TSMAX
-0.3
VSS-0.3
-55
-40
5.5
VDD+0.3
150
+85
25010
V
V
°C
°C
°Cs
Stresses above these listed maximum ratings may cause
permanent damages to the device. Exposure beyond
specified operating conditions may affect device reliability
or cause malfunction.
Handling Procedures
This device has built-in protection against high static
voltages or electric fields; however, anti-static precautions
must be taken as for any other CMOS component. Unless
otherwise specified, proper operation can only occur when
all terminal voltages are kept within the voltage range.
Unused inputs must always be tied to a defined logic
voltage level.
Electrical Characteristics
Operating Conditions (unless othewise specified)
Positive supply VDD =3.0V
Negative supply VSS =0V
Ambient temperature T = 25°C
Sensor resistance RSEN = 300 to 10K
Power Supply
Parameter Symbol Conditions Min. Typ. Max. Unit
Operating Voltage Range
Current Consumption
VDD
IDD1
IDD2
T = -20°C to 70°C
CE =VDD at standby
CE =VSS at A/D conversion
fADOSC=800kHz
2.2
100
3.0
0.2
240
3.6
1.0
300
V
µA
µA
Programmable Internal Oscillator
Parameter Symbol Conditions Min. Typ. Max. Unit
Frequency
Frequency Step Size
Stability Against Supply
Voltage Variations
Stability Against
Temperature Variations
fADOSC
fADOSC
f/f⋅∆VDD
f/T
D1,D0 = 00
2.2V< VDD <3.0V
-20°C<T<70°C
350
40
500
70
15
-300
800
120
kHz
kHz
kHz/V
Hz/°C
EM6415
Copyright 2002, EM Microelectronic-Marin SA 4 www.emmicroelectronic.com
Sensor
Parameter Symbol Conditions Min. Typ. Max. Unit
Sensor Drive Current ISDRV R RSEN1=1.0k , RSEN=4.0k,
Program step 0
Mode S
276 300 324 µA
RRSEN1=1.0k , RSEN=4.0k,
Program step 15
Mode S
468 510 552 µA
Sensor Drive Current per
Step
ISDRV /stp RRSEN1=1.0k , RSEN=4.0k10 15 20 µA/stp
Sensor Drive Current
vs Voltage Deviation
ISDRV/V RRSEN1=1.0k , RSEN=4.0k
2.2V < VDD < 3.0V
50 200 300 ppm
Sensor Bridge
Resistance1
RSEN1 RRSEN1=1.3k , ISDRV =200µA2.7 3.7 4.2 k
Sensor Bridge
Resistance2
RSEN2 RRSEN2=510 , ISDRV=500µA1.0 1.5 2.0 k
RSEN1 Resistance RRSEN1 0.3 2.5 k
RSEN2 Resistance RRSEN2 0.3 2.5 k
A/D Converter
Parameter Symbol Conditions Min. Typ. Max. Unit
Input Voltage Range FS
Resolution
Integral Nonlinearity
Differential Nonlinearity
Conversion Time
Offset Adjust Range
FS Fine Ajust Range
VSENS
RESADC
INLADC
DNLADC
TCONVAD
VOFFAD
VFSFAD
CH1,2,3,4H-CH1,2,3,4L
To resolve 14 bits ADC
fADOSC=800kHz
fADOSC=800kHz
fADOSC=800kHz
fADOSC=500kHz, 14bit
12 bit FS fine adjust
16
14
-60
-12.5
4
3
110
±40
200
+60
+12.5
mV
Bits
LSB
LSB
ms
mV
%FS
EM6415
Copyright 2002, EM Microelectronic-Marin SA 5 www.emmicroelectronic.com
DC Characteristics
Parameter Symbol Conditions Min. Typ. Max Unit
Input Low Voltage
Input High Voltage
Input Low Current
Input High Current
Output Low Voltage
Output High Voltage
VIL
VIH
IIL
IIH
VOL
VOH
ALE , RD , WR , CE , CLKP,
CLKSEL, D0-D3
ALE , RD , WR , CE , CLKP,
CLKSEL, D0-D3
ALE , RD , WR , CE , CLKP,
CLKSEL, D0-D3
ALE , RD , WR , CE , CLKP,
CLKSEL, D0 - D3
IOL = 2mA, D0 –D3
IOH = -1mA, D0 –D3
0.8VDD
-20
2.4
1
1
0.1
2.95
0.2 VDD
20
0.4
V
V
nA
nA
V
V
Timing Characteristics
Data Write cycle
VDD = 3.0V, VSS = 0V, T = 25 °C, VOH = 0.8VDD, VOL = 0.2VDD
Item Symbol Min. Typ. Max. Unit
Address Set-up Time Twas 20 25 - ns
Address Hold Time Twah 30 35 - ns
Data Set-up Time Twds 20 25 - ns
Data Hold Time Twdh 30 35 - ns
ALE Pulse Width Twap 60 65 - ns
WR Pulse Width Twwp 60 65 - ns
twap
VOH
VOL
VOH
VOL
WR
D0-D3
twas twah
VOH
VOL
twdp
twds twdh
VOH
VOL
Address Data
ALE
Fig. 3
EM6415
Copyright 2002, EM Microelectronic-Marin SA 6 www.emmicroelectronic.com
Data Read cycle
VDD = 3.0V, VSS = 0V, T = 25 °C, VOH = 0.8VDD, VOL = 0.2VDD
Item Symbol Min. Typ. Max. Unit
Address Set-up Time Tras 100 - ns
Address Hold Time Trah 40 45 - ns
Data Set-up Time Trds 20 25 - ns
Data Hold Time Trdh 20 25 - ns
ALE Pulse Width Trap 60 65 - ns
RD Pulse Width Trrp 60 65 - ns
Timing Waveforms
VOH
VOL
VOH
VOL
ALE
RD
D0-D3
tras trah
VOH
VOL
trdp
trds trdh
VOH
VOL
Address Data
VOH
VOL
Fig. 4
EM6415
Copyright 2002, EM Microelectronic-Marin SA 7 www.emmicroelectronic.com
Functional Description
EM6415 comprises a four channel analog multiplexer followed by a fixed gain amplifier followed by the integrator of the dual
slope converter, a bandgap voltage reference, RC oscillator, power on/off detector.
The sensor is supplied directly by a programmable current source.
In order to minimize noise, the analog and digital circuits internal to EM6415 use separate power supplies. These power
buses are brought out to separate pins and should be tied together as close as possible to the device.
In addition, the output of the internal bandgap voltage reference is brought to the pin VREF, which could allow the
connection of an external capacitor to VSS, if the output stability is not enough to resolve 1µV/bit ADC.
Programming Procedure
Nibble organization and Bit order:
Bit 3210
Order high →→low
Latch Address (LAD) and Functions
LAD Function Bits D0-D3 WR/RD Note
0 FS fine adjust 0-3 WR
1 FS fine adjust 4-7 WR
2 FS fine adjust 8-11 WR
3 OS rough adjust 0-3 WR
4 OS rough adjust 4-7 WR
5 FS rough adjust 0-3 WR
6 FS rough adjust 4-7 WR
7 Bridge current 0-3 WR
8 ADC status & ADC output AD0, AD1 0-3 RD (note 1)
9 ADC output AD2-AD5 2-5 RD (note 2)
10 ADC output AD6-AD9 & T0-T3 6-9 RD (note 2)
11 ADC output AD10-AD13 & T4-T7 10-13 RD (note 2)
12 ADC resolution (10, 13, 14) 0-3 WR (note 3)
13 Perform ADC conversion (T, R, S, P) 0-3 WR (note 4)
14 Select Sensor-Port (1,2,3,4) & RSEN (1,2) 0-3 WR (note 5)
15 don’t use -
Note 1: ADC Status & AD0, AD1 (LAD=8)
Bit Function Note
D0 CC Conversion complete = 1
D1 COVFL Conversion overflow = 1
D2 AD0 ADC Bit 0
D3 AD1 ADC Bit 1
Note 2: ADC read out
Latch Address 11 10 9 8
Buffer Bit 3210 3 2 1 0321032
ADC Bits
Sensor AD-14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Sensor AD-13 12 11 10 9 8 7 6 5 4 3 2 1 0 -
Sens/Pow AD10 9876 5 4 3 210----
Top of B AD10 98765 4 3 210----
EM6415
Copyright 2002, EM Microelectronic-Marin SA 8 www.emmicroelectronic.com
Note 3: ADC resolution & frequency select (LAD 12)
Bit Select Function
D1, D0 00 clock 500kHz
01 clock 600kHz
10 clock 700kHz
11 clock 800kHz
D3, D2 00 10 Bit ADC
01 13 Bit ADC
10 13 Bit ADC
11 14 Bit ADC
Note 4: ADC conversion select (LAD=13)
Bit Select Function Note
D1, D0 - don’t use
D3, D2 00 (T) top of sensor bridge with ISDRV /2 (note 6)
01 (R) A/D ramp height (note 7)
10 (S) sensor bridge signal ISDRV (note 8)
11 (P) power supply voltage (note 9)
Note 5: ADC conversion select (LAD=14)
Bit Select Function
D0 0 RSENS1
1 RSENS2
D2, D1 00 Sensor 1 on TS1
01 Sensor 2 on TS2
10 Sensor 3 on TS3
11 Sensor 4 on TS4
D3 - Don’t use
Note 6: Top of sensor bridge, e.g. temperature (ToB – VSSA)
Note 7: Select ramp height if CC=0, ramp height > 1.5V
For lowest ADC jitter, chose ramp height > 1.5V. To do so, run A/D ramp height conversion and read CC
(conversion complete, LAD8, Bit0). Lower the clock frequency until CC=0.
Note 8: Sensor bridge signal, e.g. pressure (CH1L – CH1H)
Note 9: Power supply voltage of EM6415 circuit
EM6415
Copyright 2002, EM Microelectronic-Marin SA 9 www.emmicroelectronic.com
Integrator
This signal can be seen on pin CINT
t1 t2 t3
A
A D
D
min. 1.5V for 14Bit at
OFFSET ROUGH ADJUST FS ROUGH ADJUST
A
D
FS FINE ADJUST
14Bit ADC OUTPUT
3V power supply
12Bit
8Bit 8Bit
0.720V dV1
dV2
Fig. 5 Integrator ramp
Time Phase Execution
t1 Autozero phase Set up of integrator starting point
t 2 FS fine adjust Signal integration with preprogrammed counter time length t2
t 3 FS rough adjust De-integration with preprogrammed reference voltage, time length of
t3 = ADC output counts
dV1 is the Offset Rough Adjust
dV2 is the Integrator Ramp Length
Offsets and other system mismatch such as the zero drift of operational amplifiers, long term instabilities or supply
voltage fluctuations are cancelled during the Autozero phase.
Sensitivity and full-scale range adjustments are done during rampup and rampdown of the dual slope integrator.
EM6415
Copyright 2002, EM Microelectronic-Marin SA 10 www.emmicroelectronic.com
Pad Description & Pin Assignment in SSOP36
PIN Nr Name I/O Description
10 TS1 Top of sensor1 bridge connection pin
11 CH1H Sensor1 channel high signal in
12 CH1L Sensor1 channel low signal in
13 TS2 Top of sensor2 bridge connection pin
14 CH2H Sensor2 channel high signal in
15 CH2L Sensor2 channel low signal in
16 TS3 Top of sensor3 bridge connection pin
17 CH3H Sensor3 channel high signal in
18 CH3L Sensor3 channel low signal in
19 TS4 Top of sensor4 bridge connection pin
20 CH4H Sensor4 channel high signal in
21 CH4L Sensor4 channel low signal in
2 D0P I/O Microprocessor Port Data 0
1 D1P I/O Microprocessor Port Data 1
36 D2P I/O Microprocessor Port Data 2
35 D3P I/O Microprocessor Port Data 3
31 RD I Read strobe for BUS read (active low)
32 ALE I Address latch enable (active low)
33 CE I Chip enable (active low)
34 WR I Write strobe for BUS write (active low)
22 CINT Connection to integrator capacitor
23 AZN Connection to auto-zero capacitor
24 P3WAY 3 way connection for integrator
25 RINT13_14 Connection of resistor for integrator
26 RINT10 Connection of resistor for integrator when 10 bit conversion used
8 RSEN1 Resistor to select sensor bridge1 maximum drive current
9 RSEN2 Resistor to select sensor bridge2 maximum drive current
3 CLKP I External clock input
5 CLKSEL I Internal/external clock select
6 VDDD Positive supply voltage of digital part
7 VDDA Positive supply voltage of analog part
29 VSSA Negative supply voltage of analog part
30 VSSD Negative supply voltage of digital part
27 VREF O Reference voltage
4, 28 NC Not connected
I: Input O: Output
EM6415
Copyright 2002, EM Microelectronic-Marin SA 11 www.emmicroelectronic.com
Package Information
SSOP36 – 300 mils
Symbol Common dimensions (inches) Note Symbol Common dimensions (mm) Note
Min Nom Max Min. Nom Max
A 0.097 0.101 0.104 A 2.46 2.56 2.64
A1 0.0050 0.009 0.0115 A1 0.127 0.22 0.29
A2 0.090 0.092 0.094 A2 2.29 2.34 2.39
B 0.012 0.014 0.017 B 0.31 0.36 0.43
C 0.0091 0.010 0.0125 C 0.23 0.25 0.32
D 0.602 0.607 0.612 D 15.29 15.42 15.54
E 0.292 0.296 0.299 E 7.42 7.52 7.59
e 0.0315
BSC
e0.80
BSC
H 0.400 0.406 0.410 H 10.16 10.31 10.41
h 0.010 0.013 0.016 h 0.25 0.33 0.41
L 0.024 0.032 0.040 L 0.61 0.81 1.02
X 0.085 0.093 0.100 X 2.16 2.36 2.54
α α
EM6415
Copyright 2002, EM Microelectronic-Marin SA 12 www.emmicroelectronic.com
Ordering Information
The EM6415 has metal mask options for the Gain of the Input Amplifier (between 1 and 150 max) and for the Offset Adjust
Range. Contact EM Microelectronic for availability of different options not shown in table below. Please make sure to order
the exact Part Number when ordering.
Part Number Version
Input
Amplifier
Gain
OS/FS Rough Adjust
(note 1)
Offset Adjust
Range Delivery Form
EM6415V1WS11 Sawn wafer, 11 mils thickness
EM6415V1SS36A V1 5 Separate Registers -40mV to +40mV 36-pin SSOP, Stick
EM6415V1SS36B for each sensor 36 pin SSOP, Tape & Reel
EM6415V2WS11 Sawn wafer, 11 mils thickness
EM6415V2SS36A V2 5 Common Registers -40mV to +40mV 36-pin SSOP, Stick
EM6415V2SS36B for the 4 sensors 36 pin SSOP, Tape & Reel
EM6415V3WS11 Sawn wafer, 11 mils thickness
EM6415V3SS36A V3 150 Separate Registers -40mV to +40mV 36-pin SSOP, Stick
EM6415V3SS36B for each sensor 36 pin SSOP, Tape & Reel
EM6415V%WS11 Sawn wafer, 11 mils thickness
EM6415V%SS36A V% custom custom custom 36-pin SSOP, Stick
EM6415V%SS36B 36 pin SSOP, Tape & Reel
Note 1: LAD 3, 4, 5, 6
For die size information and pad location diagram, please contact EM Microelectronic-Marin SA.
© EM Microelectronic-Marin SA, 11/02, Rev. B
EM Microelectronic-Marin SA cannot assume responsibility for use of any circuitry described other than circuitry
entirely embodied in an EM Microelectronic-Marin SA product. EM Microelectronic-Marin SA reserves the right to
change the circuitry and specifications without notice at any time. You are strongly urged to ensure that the
information given has not been superseded by a more up-to-date version.