MAX187 Datasheet, PDF (1/20 Pages) Maxim Integrated Products – +5V, Low-Power, 12-Bit Serial ADCs

19-0196; Rev 0; 10/93
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+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 micro-
controllers. 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 con-
sumption combined with ease of use and small pack-
age 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
o 12-Bit Resolution
o ±¹â„2 LSB Integral Nonlinearity (MAX187A/MAX189A)
o Internal Track/Hold, 75kHz Sampling Rate
o Single +5V Operation
o Low Power: 2µA Shutdown Current
1.5mA Operating Current
o Internal 4.096V Buffered Reference (MAX187)
o 3-Wire Serial Interface, Compatible with SPI,
QSPI, and Microwire
o Small-Footprint 8-Pin DIP and 16-Pin SO
_________________Ordering Information
PART
MAX187ACPA
MAX187BCPA
MAX187CCPA
MAX187ACWE
MAX187BCWE
MAX187CCWE
MAX187BC/D
TEMP. RANGE
PIN-PACKAGE
ERROR
(LSB)
0°C to +70°C 8 Plastic DIP ±¹â„2
0°C to +70°C 8 Plastic DIP ±1
0°C to +70°C
0°C to +70°C
8 Plastic DIP ±2
16 Wide SO
±¹â„2
0°C to +70°C 16 Wide SO
±1
0°C to +70°C 16 Wide SO
±2
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
5
GND
REF ⁴
2
AIN
1
VDD
+2.5V
BANDGAP
REF-
AV = 1.638
DAC
10k
(4.096V)
REF+
REFERENCE
(MAX187 ONLY)
OUTPUT
SHIFT
REGISTER
12-BIT
SAR
T/H
MAX187
MAX189
COMPARATOR
BUFFER ENABLE/DISABLE ^CONTROL
AND
TIMING
6
DOUT
8
SCLK
7
CS
3
SHDN
NOTE: PIN NUMBERS SHOWN ARE FOR 8-PIN DIPs ONLY.
TOP VIEW
VDD ₁
AIN 2
SHDN 3
REF 4
MAX187
MAX189
8 SCLK
7 CS
6 DOUT
5 GND
DIP
Pin Configurations continued on last page.
™ SPI and QSPI are trademarks of Motorola. Microwire is a trademark of National Semiconductor.
________________________________________________________________ Maxim Integrated Products 1
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