General Description

The MAX1291/MAX1293 low-power, 12-bit analog-to-digital converters (ADCs) feature a successive-approximation ADC, automatic power-down, fast wake-up (2µs), an on-chip clock, +2.5V internal reference, and a high speed, byte-wide parallel interface. They operate with a single +3V analog supply and feature a VLOGIC pin that allows them to interface directly with a +1.8V to +5.5V digital supply.

Power consumption is only 5.7mW (VDD = VLOGIC) at the maximum sampling rate of 250ksps. Two software-selectable power-down modes enable the MAX1291/MAX1293 to be shut down between conversions; accessing the parallel interface returns them to normal operation. Powering down between conversions can cut supply current to under 10µA at reduced sampling rates.

Both devices offer software-configurable analog inputs for unipolar/bipolar and single-ended/pseudo-differential operation. In single-ended mode, the MAX1291 has eight input channels and the MAX1293 has four input channels (four and two input channels, respectively, when in pseudo-differential mode).

Excellent dynamic performance and low power, combined with ease of use and small package size, make these converters ideal for battery-powered and data acquisition applications or for other circuits with demanding power consumption and space requirements.

The MAX1291/MAX1293 tri-states INT when CS goes high. Refer to MAX1261/MAX1263 if tri-stating INT is not desired.

The MAX1291 is available in a 28-pin QSOP package, while the MAX1293 is available in a 24-pin QSOP. For pin-compatible +5V, 12-bit versions, refer to the MAX1290/MAX1292 data sheet.

Features

♦ 12-Bit Resolution, ±0.5 LSB Linearity

♦ +3V Single Operation

♦ User-Adjustable Logic Level (+1.8V to +3.6V)

♦ Internal +2.5V Reference

♦ Software-Configurable, Analog Input Multiplexer

   8-Channel Single-Ended/

   4-Channel Pseudo-Differential (MAX1291)

   4-Channel Single-Ended/

   2-Channel Pseudo-Differential (MAX1293)

♦ Software-Configurable, Unipolar/Bipolar Inputs

♦ Low Power: 1.9mA (250ksps)

   1.0mA (100ksps)

   400µA (10ksps)

   2µA (Shutdown)

♦ Internal 3MHz Full-Power Bandwidth Track/Hold

♦ Byte-Wide Parallel (8 + 4) Interface

♦ Small Footprint:

   28-Pin QSOP (MAX1291)

   24-Pin QSOP (MAX1293)

Applications

   Industrial Control Systems

   Data Logging

   Energy Management

   Patient Monitoring

   Data-Acquisition Systems

   Touch Screens