3 Volt Single Chip 12-Bit Data Acquisition System

The LTC1289 is a 3V data acquisition component which contains a serial I/O successive approximation A/D converter. The device specifications are guaranteed at a supply voltage of 2.7V. It uses LTCMOS™ switched capacitor technology to perform a 12-bit unipolar, or 11-bit plus sign bipolar A/D conversion. The 8 channel input multiplexer can be configured for either single-ended or differential inputs (or combinations thereof). An on-chip sample and hold is included for all single-ended input channels. When the LTC1289 is idle it can be powered down in applications where low power consumption is desired.

The serial I/O is designed to be compatible with industry standard full duplex serial interfaces. It allows either MSB- or LSB- first data and automatically provides 2’s complement output coding in the bipolar mode. The output data word can be programmed for a length of 8, 12 or 16 bits. This allows easy interface to shift registers and a variety of processors.

Applications

* Minimum Guaranteed Supply Voltage: 2.7V

* Resolution: 12 Bits

* Fast Conversion Time: 26µs Max Over Temp

* Low Supply Currents: 1.0mA

* Single Supply 3.3V or ±3.3V Operation

* Software Programmable Features

* Unipolar/Bipolar Conversions

* 4 Differential/8 Single-Ended Inputs

* Variable Data Word Length

* Power Shutdown

* Built-In Sample-and-Hold

* Direct 4-Wire Interface to Most MPU Serial Ports and all MPU Parallel Ports

* 25kHz Maximum Throughput Rate

* Available in 20-Lead PDIP and 20-Lead SW Packages