19-1231; Rev 2; 4/11
+5V, Low-Power, Multi-Channel,
Serial 8-Bit ADCs
General Description
____________________________Features
The MAX1112/MAX1113 low-power, 8-bit, 8-channel
analog-to-digital converters (ADCs) feature an internal
track/hold, voltage reference, clock, and serial inter-
face. They operate from a single 4.5V to 5.5V supply
and consume only 135µA while sampling at rates up to
50ksps. The MAX1112’s 8 analog inputs and the
MAX1113’s 4 analog inputs are software-configurable,
allowing unipolar/bipolar and single-ended/differential
operation.
♦ 4.5V to 5.5V Single Supply
♦ Low Power: 135µA at 50ksps
13µA at 1ksps
♦ 8-Channel Single-Ended or 4-Channel Differential
Inputs (MAX1112)
♦ 4-Channel Single-Ended or 2-Channel Differential
Inputs (MAX1113)
Successive-approximation conversions are performed
using either the internal clock or an external serial-inter-
face clock. The full-scale analog input range is deter-
mined by the 4.096V internal reference, or by an
♦ Internal Track/Hold; 50kHz Sampling Rate
♦ Internal 4.096V Reference
♦ SPI/QSPI/MICROWIRE-Compatible Serial Interface
♦ Software-Configurable Unipolar or Bipolar Inputs
externally applied reference ranging from 1V to V
.
DD
The 4-wire serial interface is compatible with the SPI™,
QSPI™, and MICROWIRE™ serial-interface standards.
A serial-strobe output provides the end-of-conversion
signal for interrupt-driven processors.
♦ Total Unadjusted Error: 1 LSB (max)
0.3 LSB (typ)
The MAX1112/MAX1113 have a software-program-
mable, 2µA automatic power-down mode to minimize
power consumption. Using power-down, the supply
current is reduced to 13µA at 1ksps, and only 82µA at
10ksps. Power-down can also be controlled using the
SHDN input pin. Accessing the serial interface automat-
ically powers up the device.
Ordering Information continued at end of data sheet.
Functional Diagram
CS
SCLK
The MAX1112 is available in a 20-pin SSOP package.
The MAX1113 is available in a small 16-pin QSOP
package.
INPUT
INT
SHIFT
REGISTER
DIN
CLOCK
CONTROL
LOGIC
SHDN
________________________Applications
Portable Data Logging
CH0
CH1
CH2
OUTPUT
SHIFT
REGISTER
DOUT
SSTRB
ANALOG
INPUT
MUX
Hand-Held Measurement Devices
Medical Instruments
CH3
T/H
CH4*
CH5*
CH6*
CH7*
CLOCK
IN
8-BIT
SAR ADC
OUT
System Diagnostics
REF
V
DD
COM
Solar-Powered Remote Systems
DGND
AGND
+4.096V
REFERENCE
REFOUT
MAX1112
MAX1113
4mA to 20mA-Powered Remote
Data-Acquisition Systems
REFIN
*MAX1112 ONLY
Pin Configurations appear at end of data sheet.
SPI and QSPI are trademarks of Motorola, Inc.
MICROWIRE is a trademark of National Semiconductor Corp.
________________________________________________________________ Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.