Features

• Software Programmable Features
• Unipolar/Bipolar Conversions
• 4 Differential/8 Single Ended Inputs
• MSB or LSB First Data Sequence
• Variable Data Word Length
• Built in Sample and Hold
• Single Supply 5V, 10V or ±5V Operation
• Direct 4 Wire Interface to Most MPU Serial Ports and All MPU Parallel Ports
• 30kHz Maximum Throughput Rate

Typical Application

Description

The LTC™1090 is a data acquisition component which contains a serial I/O successive approximation A/D converter. It uses LTCMOS® switched capacitor technology to perform either 10-bit unipolar, or 9-bit plus sign bipolar A/D conversions. 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.

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, 10, 12 or 16 bits. This allows easy interface to shift registers and a variety of processors.

The LTC1090A is specified with total unadjusted error (including the effects of offset, linearity and gain errors) less than �0.5LSB.

The LTC1090 is specified with offset and linearity less than �0.5LSB but with a gain error limit of �2LSB for applications where gain is adjustable or less critical.