General Description

The MAX1112/MAX1113 are low-power, 8-bit, 8-channel analog-to-digital converters (ADCs) that feature an internal track/hold, voltage reference, clock, and serial interface. 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.

Successive-approximation conversions are performed using either the internal clock or an external serial-interface clock. The full-scale analog input range is determined by the 4.096V internal reference, or by an externally applied reference ranging from 1V to VDD. 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.

The MAX1112/MAX1113 have a software-programmable, 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 automatically powers up the device.

The MAX1112 is available in 20-pin SSOP and DIP packages. The MAX1113 is available in small 16-pin QSOP and DIP packages.

Features

♦ +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)

♦ Internal Track/Hold; 50kHz Sampling Rate

♦ Internal 4.096V Reference

♦ SPI/QSPI/MICROWIRE-Compatible Serial Interface

♦ Software-Configurable Unipolar or Bipolar Inputs

♦ Total Unadjusted Error: ±1LSB (max) ±0.3LSB (typ)

Applications

   Portable Data Logging

   Hand-Held Measurement Devices

   Medical Instruments

   System Diagnostics

   Solar-Powered Remote Systems

   4–20mA-Powered Remote

      Data-Acquisition Systems