19-0196; Rev 0; 10/93 |
|
|
KIT |
MANUAL |
|
|
SHEET |
|
EVALUATION |
|
|
DATA |
|
|
FOLLOWS |
|
|
+5V, Low-Power, 12-Bit Serial ADCs
__________________General Description
The MAX187/MAX189 serial 12-bit analog-to-digital converters (ADCs) operate from a single +5V supply and accept a 0V to 5V analog input. Both parts feature an 8.5µs successive-approximation ADC, a fast track/hold (1.5µs), an on-chip clock, and a high-speed 3-wire serial interface.
The MAX187/MAX189 digitize signals at a 75ksps throughput rate. An external clock accesses data from the interface, which communicates without external hardware to most digital signal processors and microcontrollers. The interface is compatible with SPI™, QSPI™, and Microwire™.
The MAX187 has an on-chip buffered reference, and the MAX189 requires an external reference. Both the MAX187 and MAX189 save space with 8-pin DIP and 16-pin SO packages. Power consumption is 7.5mW and reduces to only 10µW in shutdown.
Excellent AC characteristics and very low power consumption combined with ease of use and small package size make these converters ideal for remote DSP and sensor applications, or for circuits where power consumption and space are crucial.
___________________________Applications
Portable Data Logging
Remote Digital Signal Processing
Isolated Data Acquisition
High-Accuracy Process Control
________________Functional Diagram
________________________________Features
♦12-Bit Resolution
♦± 1⁄2 LSB Integral Nonlinearity (MAX187A/MAX189A)
♦Internal Track/Hold, 75kHz Sampling Rate
♦Single +5V Operation
♦Low Power: 2µA Shutdown Current
1.5mA Operating Current
♦Internal 4.096V Buffered Reference (MAX187)
♦3-Wire Serial Interface, Compatible with SPI, QSPI, and Microwire
♦Small-Footprint 8-Pin DIP and 16-Pin SO
_________________Ordering Information
PART |
TEMP. RANGE PIN-PACKAGE |
ERROR |
||
|
|
|
(LSB) |
|
MAX187ACPA |
0°C to +70°C |
8 Plastic DIP |
±1⁄2 |
|
MAX187BCPA |
0°C to +70°C |
8 Plastic DIP |
±1 |
|
|
|
|
|
|
MAX187CCPA |
0°C to +70°C |
8 Plastic DIP |
±2 |
|
|
|
|
|
|
MAX187ACWE |
0°C to +70°C |
16 Wide SO |
±1⁄2 |
|
MAX187BCWE |
0°C to +70°C |
16 Wide SO |
±1 |
|
|
|
|
|
|
MAX187CCWE |
0°C to +70°C |
16 Wide SO |
±2 |
|
|
|
|
|
|
MAX187BC/D |
0°C to +70°C |
Dice* |
±1 |
|
|
|
|
|
|
Ordering Information continued on last page.
*Dice are specified at TA = +25°C, DC parameters only.
**Contact factory for availability and processing to MIL-STD-883.
_________________Pin Configurations
|
|
|
|
|
|
6 |
TOP VIEW |
|
|
|
|
GND5 |
|
|
|
OUTPUT |
8 DOUT |
|
|
|
|
|
|
|
|
REF- |
SHIFT |
SCLK |
|
|
|
|
|
||
|
|
|
AV = 1.638 |
DAC |
REGISTER |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
||
|
|
10k |
|
|
|
|
|
|
|
|
|
|
|
|
(4.096V) |
|
|
VDD |
1 |
|
8 |
SCLK |
|
|
|
+2.5V |
|
|
|
|
|||||
|
|
BANDGAP |
|
REF+ |
|
|
|
|
|
|
|
|
|
|
|
|
|
AIN |
2 |
|
7 |
CS |
|
|
|
REFERENCE |
|
|
12-BIT |
|
MAX187 |
||||
|
4 |
(MAX187 ONLY) |
|
|
|
SHDN |
3 |
6 |
DOUT |
||
REF |
|
|
SAR |
|
MAX189 |
||||||
|
|
|
|
|
|||||||
|
|
|
|
|
|
REF |
4 |
|
5 |
GND |
|
AIN2 |
|
|
|
|
|
|
|||||
T/H |
|
|
|
|
|
|
|
|
|
||
|
|
|
|
COMPARATOR |
7 |
|
|
DIP |
|
|
|
|
|
MAX187 |
|
|
|
|
|
|
|
||
|
|
BUFFER ENABLE/DISABLE |
CONTROL |
CS |
|
|
|
|
|
||
|
|
MAX189 |
|
|
|
|
|
|
|||
|
|
|
|
AND |
3 |
|
|
|
|
|
|
|
1 |
|
|
|
|
|
|
|
|
||
VDD |
|
|
|
TIMING |
|
|
|
|
|
||
|
|
|
|
|
SHDN |
|
|
|
|
|
NOTE: PIN NUMBERS SHOWN ARE FOR 8-PIN DIPs ONLY. |
Pin Configurations continued on last page. |
™ SPI and QSPI are trademarks of Motorola. Microwire is a trademark of National Semiconductor.
________________________________________________________________ Maxim Integrated Products 1
MAX187/MAX189
Call toll free 1-800-998-8800 for free samples or literature.
+5V, Low-Power, 12-Bit Serial ADCs
MAX187/MAX189
ABSOLUTE MAXIMUM RATINGS
VDD to GND ............................................................. |
-0.3V to +6V |
AIN to GND................................................ |
-0.3V to (VDD + 0.3V) |
REF to GND ............................................... |
-0.3V to (VDD + 0.3V) |
Digital Inputs to GND................................. |
-0.3V to (VDD + 0.3V) |
Digital Outputs to GND.............................. |
-0.3V to (VDD + 0.3V) |
SHDN to GND............................................. |
-0.3V to (VDD + 0.3V) |
REF Load Current (MAX187) ......................... |
4.0mA Continuous |
REF Short-Circuit Duration (MAX187)................................ |
20sec |
DOUT Current.................................................................. |
±20mA |
Continuous Power Dissipation (TA = +70°C) |
|
|
8-Pin Plastic DIP (derate 9.09mW/°C above +70°C) |
..500mW |
|
16-Pin Wide SO (derate 8.70mW/°C above +70°C) ... |
478mW |
|
8-Pin CERDIP (derate 8.00mW/°C above +70°C) ...... |
440mW |
|
Operating Temperature Ranges: |
|
|
MAX187_C_ _/MAX189_C_ _............................. |
0°C to +70°C |
|
MAX187_E_ _/MAX189_E_ _ .......................... |
-40°C to +85°C |
|
MAX187_MJA/MAX189_MJA ....................... |
-55°C to +125°C |
|
Storage Temperature Range............................ |
-60°C to +150°C |
|
Lead Temperature (soldering, 10sec)............................ |
|
+300°C |
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(VDD = +5V ±5%; GND = 0V; unipolar input mode; 75ksps, fCLK = 4.0MHz, external clock (50% duty cycle); MAX187—internal reference: VREF = 4.096V, 4.7µF capacitor at REF pin, or MAX189—external reference: VREF = 4.096V applied to REF pin, 4.7µF capacitor at REF pin; TA = TMIN to TMAX; unless otherwise noted.)
PARAMETER |
SYMBOL |
CONDITIONS |
MIN |
TYP |
MAX |
UNITS |
|
|
|
|
|
|
|
DC ACCURACY (Note 1) |
|
|
|
|
|
|
|
|
|
|
|
|
|
Resolution |
|
|
|
|
12 |
Bits |
|
|
|
|
|
|
|
|
|
MAX18_A |
|
|
±1⁄2 |
|
Relative Accuracy (Note 2) |
|
MAX18_B |
|
|
±1 |
LSB |
|
|
|
|
|
|
|
|
|
MAX18_C |
|
|
±2 |
|
|
|
|
|
|
|
|
Differential Nonlinearity |
DNL |
No missing codes over temperature |
|
|
±1 |
LSB |
|
|
|
|
|
|
|
Offset Error |
|
MAX18_A |
|
|
±11⁄2 |
LSB |
|
MAX18_B/C |
|
|
±3 |
||
|
|
|
|
|
||
|
|
|
|
|
|
|
|
|
MAX187 |
|
|
±3 |
|
Gain Error (Note 3) |
|
|
|
|
|
LSB |
|
MAX189A |
|
|
±1 |
||
|
|
|
|
|
|
|
|
|
MAX189B/C |
|
|
±3 |
|
|
|
|
|
|
|
|
Gain Temperature Coefficient |
|
External reference, 4.096V |
|
±0.8 |
|
ppm/°C |
|
|
|
|
|
|
|
DYNAMIC SPECIFICATIONS (10kHz sine wave input, 0V to 4.096Vp-p, 75ksps) |
|
|
|
|
||
Signal-to-Noise plus |
SINAD |
|
70 |
|
|
dB |
Distortion Ratio |
|
|
|
|||
|
|
|
|
|
|
|
Total Harmonic Distortion |
THD |
|
|
|
-80 |
dB |
(up to the 5th harmonic) |
|
|
|
|||
|
|
|
|
|
|
|
Spurious-Free Dynamic Range |
SFDR |
|
80 |
|
|
dB |
|
|
|
|
|
|
|
Small-Signal Bandwidth |
|
Rolloff -3dB |
|
4.5 |
|
MHz |
|
|
|
|
|
|
|
Full-Power Bandwidth |
|
|
|
0.8 |
|
MHz |
|
|
|
|
|
|
|
2 _______________________________________________________________________________________
+5V, Low-Power, 12-Bit Serial ADCs
ELECTRICAL CHARACTERISTICS (continued)
(VDD = +5V ±5%; GND = 0V; unipolar input mode; 75ksps, fCLK = 4.0MHz, external clock (50% duty cycle); MAX187—internal reference: VREF = 4.096V, 4.7µF capacitor at REF pin, or MAX189—external reference: VREF = 4.096V applied to REF pin, 4.7µF capacitor at REF pin; TA = TMIN to TMAX; unless otherwise noted.)
PARAMETER |
SYMBOL |
CONDITIONS |
MIN |
TYP |
MAX |
UNITS |
||
|
|
|
|
|
|
|
|
|
CONVERSION RATE |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Conversion Time |
tCONV |
|
|
|
5.5 |
|
8.5 |
µs |
Track/Hold Acquisition Time |
tACQ |
|
|
|
1.5 |
|
|
µs |
Throughput Rate |
|
External clock, 4MHz, 13 clocks |
|
|
75 |
ksps |
||
|
|
|
|
|
|
|
|
|
Aperture Delay |
tAPR |
|
|
|
|
10 |
|
ns |
Aperture Jitter |
|
|
|
|
|
<50 |
|
ps |
|
|
|
|
|
|
|
|
|
ANALOG INPUT |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Input Voltage Range |
|
|
|
|
|
|
0 to VREF |
V |
Input Capacitance (Note 4) |
|
|
|
|
|
16 |
|
pF |
|
|
|
|
|
|
|
|
|
INTERNAL REFERENCE (MAX187 only, reference buffer enabled) |
|
|
|
|
|
|||
|
|
|
|
|
|
|
|
|
|
|
TA = +25°C |
|
|
4.076 |
4.096 |
4.116 |
|
REF Output Voltage |
VREF |
|
|
MAX187_C |
4.060 |
|
4.132 |
|
|
|
|
|
|
|
V |
||
TA = TMIN to TMAX |
|
MAX187_E |
4.050 |
|
4.140 |
|||
|
|
|
|
|||||
|
|
|
|
|
||||
|
|
|
|
MAX187_M |
4.040 |
|
4.150 |
|
REF Short-Circuit Current |
|
|
|
|
|
|
30 |
mA |
|
|
|
|
|
|
|
|
|
|
|
MAX187AC/BC |
|
|
±30 |
±50 |
|
|
|
|
|
|
|
|
|
|
|
REF Tempco |
|
MAX187AE/BE |
|
|
±30 |
±60 |
ppm/°C |
|
|
|
|
|
|
|
|
||
|
MAX187AM/BM |
|
|
±30 |
±80 |
|||
|
|
|
|
|
||||
|
|
|
|
|
|
|
|
|
|
|
MAX187C |
|
|
±30 |
|
|
|
|
|
|
|
|
|
|
|
|
Load Regulation (Note 5) |
|
0mA to 0.6mA output load |
|
|
1 |
|
mV |
|
|
|
|
|
|
|
|
|
|
EXTERNAL REFERENCE AT REF (Buffer disabled, VREF = 4.096V) |
|
|
|
|
|
|||
Input Voltage Range |
|
|
|
|
2.50 |
|
VDD + 50mV |
V |
Input Current |
|
|
|
|
|
200 |
350 |
µA |
|
|
|
|
|
|
|
|
|
Input Resistance |
|
|
|
|
12 |
20 |
|
kΩ |
|
|
|
|
|
|
|
|
|
Shutdown REF Input Current |
|
|
|
|
|
1.5 |
10 |
µA |
|
|
|
|
|
|
|
|
|
MAX187/MAX189
_______________________________________________________________________________________ 3
+5V, Low-Power, 12-Bit Serial ADCs
MAX187/MAX189
ELECTRICAL CHARACTERISTICS (continued)
(VDD = +5V ±5%; GND = 0V; unipolar input mode; 75ksps, fCLK = 4.0MHz, external clock (50% duty cycle); MAX187—internal reference: VREF = 4.096V, 4.7µF capacitor at REF pin, or MAX189—external reference: VREF = 4.096V applied to REF pin, 4.7µF capacitor at REF pin; TA = TMIN to TMAX; unless otherwise noted.)
PARAMETER |
SYMBOL |
CONDITIONS |
MIN |
TYP |
MAX |
UNITS |
|
|
|
|
|
|
|
|
|
DIGITAL INPUTS (SCLK, , |
) |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
SCLK, CS Input High Voltage |
VINH |
|
|
2.4 |
|
|
V |
SCLK, CS Input Low Voltage |
VINL |
|
|
|
|
0.8 |
V |
SCLK, CS Input Hysteresis |
VHYST |
|
|
|
0.15 |
|
V |
SCLK, CS Input Leakage |
IIN |
VIN = 0V or VDD |
|
|
±1 |
µA |
|
SCLK, CS Input Capacitance |
CIN |
(Note 4) |
|
|
15 |
pF |
|
SHDN Input High Voltage |
VINSH |
|
|
VDD - 0.5 |
|
|
V |
SHDN Input Low Voltage |
VINSL |
|
|
|
|
0.5 |
V |
SHDN Input Current |
IINS |
SHDN = VDD or 0V |
|
|
±4.0 |
µA |
|
SHDN Input Mid Voltage |
VIM |
|
|
1.5 |
|
VDD -1.5 |
V |
SHDN Voltage, Floating |
VFLT |
SHDN = open |
|
2.75 |
|
V |
|
SHDN Maximum Allowed |
|
SHDN = open |
-100 |
|
100 |
nA |
|
Leakage, Mid Input |
|
|
|||||
|
|
|
|
|
|
|
|
DIGITAL OUTPUT (DOUT) |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Output Voltage Low |
VOL |
ISINK = 5mA |
|
|
0.4 |
V |
|
ISINK = 16mA |
|
0.3 |
|
||||
Output Voltage High |
VOH |
ISOURCE = 1mA |
4 |
|
|
V |
|
Three-State Leakage Current |
IL |
CS = 5V |
|
|
±10 |
µA |
|
Three-State Output |
COUT |
CS = 5V (Note 4) |
|
|
15 |
pF |
|
Capacitance |
|
|
|||||
POWER REQUIREMENTS |
|
|
|
|
|
|
|
Supply Voltage |
VDD |
|
|
4.75 |
|
5.25 |
V |
|
|
Operating mode |
MAX187 |
|
1.5 |
2.5 |
mA |
|
|
|
|
|
|
||
Supply Current |
IDD |
MAX189 |
|
1.0 |
2.0 |
||
|
|
|
|||||
|
|
Power-down mode |
|
2 |
10 |
µA |
|
|
|
|
|
|
|
|
|
Power-Supply Rejection |
PSR |
VDD = +5V, ±5%; external reference, 4.096V; |
|
±0.06 |
±0.5 |
mV |
|
|
|
full-scale input (Note 6) |
|
|
|
|
|
|
|
|
|
|
|
|
|
4 _______________________________________________________________________________________
+5V, Low-Power, 12-Bit Serial ADCs
TIMING CHARACTERISTICS
(VDD = +5.0V ±5%, TA = TMIN to TMAX, unless otherwise noted.)
PARAMETER |
SYMBOL |
|
|
CONDITIONS |
MIN |
TYP |
MAX |
UNITS |
||
|
|
|
|
|
|
|
|
|
||
Track/Hold Acquisition Time |
tACQ |
CS = high (Note 7) |
1.5 |
|
|
µs |
||||
SCLK Fall to Output Data Valid |
t |
C |
LOAD |
= 100pF |
|
MAX18_ _C/E |
20 |
|
150 |
ns |
|
DO |
|
|
|
MAX18_ _M |
20 |
|
200 |
|
|
|
|
|
|
|
|
|
|
|||
|
|
|
|
|
|
|
|
|||
CS Fall to Output Enable |
tDV |
CLOAD = 100pF |
|
|
100 |
ns |
||||
CS Rise to Output Disable |
tTR |
CLOAD = 100pF |
|
|
100 |
ns |
||||
SCLK Clock Frequency |
fSCLK |
|
|
|
|
|
|
|
5 |
MHz |
SCLK Pulse Width High |
tCH |
|
|
|
|
|
100 |
|
|
ns |
SCLK Pulse Width Low |
tCL |
|
|
|
|
|
100 |
|
|
ns |
SCLK Low to CS Fall |
tCSO |
|
|
|
|
|
50 |
|
|
ns |
Setup Time |
|
|
|
|
|
|
|
|
|
|
CS Pulse Width |
tCS |
|
|
|
|
|
500 |
|
|
ns |
Note 1: Tested at VDD = +5V.
Note 2: Relative accuracy is the deviation of the analog value at any code from its theoretical value after the full-scale range has been calibrated.
Note 3: MAX187—internal reference, offset nulled; MAX189–external +4.096V reference, offset nulled. Excludes reference errors. Note 4: Guaranteed by design. Not subject to production testing.
Note 5: External load should not change during conversion for specified ADC accuracy. Note 6: DC test, measured at 4.75V and 5.25V only.
Note 7: To guarantee acquisition time, tACQ is the maximum time the device takes to acquire the signal, and is also the minimum time needed for the signal to be acquired.
MAX187/MAX189
_______________________________________________________________________________________ 5
+5V, Low-Power, 12-Bit Serial ADCs
MAX187/MAX189
________________________________________________Typical Operating Characteristics
POWER-SUPPLY REJECTION vs.
TEMPERATURE
|
0.16 |
|
(mV) |
0.14 |
|
0.12 |
||
REJECTION |
||
0.10 |
||
|
||
SUPPLY |
0.08 |
|
0.06 |
||
- |
|
|
POWER |
0.04 |
|
|
||
|
0.02 |
|
|
0 |
-60 |
-20 |
20 |
60 |
100 |
140 |
|
|
TEMPERATURE (°C) |
|
|
SUPPLY CURRENT vs. TEMPERATURE
(mA) |
2.2 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
||
|
|
|
|
|
|
|
|
|
|
|
|
|
||
1.8 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
CURRENT |
1.4 |
|
|
|
|
|
|
|
MAX187 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|||||
|
|
|
|
|
|
|
|
|
|
|
|
|
||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
SUPPLY |
1.0 |
|
|
|
|
|
|
|
MAX189 |
|
|
|
|
|
|
0.6 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
0.2 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
-60 |
-20 |
20 |
|
60 |
|
100 |
140 |
||||||
|
|
|
|
|
TEMPERATURE (°C) |
|
|
|
|
VREF vs. TEMPERATURE
|
4.090 |
|
(V) |
4.089 |
|
4.088 |
||
VOLTAGE |
||
4.087 |
||
|
||
REFERENCE |
4.086 |
|
4.085 |
||
|
||
INTERNAL |
4.084 |
|
4.083 |
||
|
4.082
4.081
4.080
-60 |
-20 |
20 |
60 |
100 |
140 |
TEMPERATURE (°C)
SHUTDOWN SUPPLY CURRENT vs.
TEMPERATURE
|
7 |
A) |
6 |
(μ |
|
CURRENT |
5 |
|
|
SUPPLY |
4 |
3 |
|
SHUTDOWN |
2 |
|
|
|
1 |
|
0 |
-60 |
-20 |
20 |
60 |
100 |
140 |
TEMPERATURE (°C)
6 _______________________________________________________________________________________