1

LTC1289

1289fb

3 Volt Single Chip 12-Bit

Data Acquisition System

■

Single Supply 3.3V or

±3.3V Operation

Unipolar/Bipolar Conversions

4 Differential/8 Single-Ended Inputs

Variable Data Word Length

Power Shutdown

■

Built-In Sample-and-Hold

and All MPU Parallel Ports

■

25kHz Maximum Throughput Rate

Single Cell 3V 12-Bit Data Acquisition System

µs Max Over Temp

The LTC

contains a serial I/O successive approximation A/D con-

verter. The device specifications are guaranteed at a

supply voltage of 2.7V. It uses LTCMOS

pacitor 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 comple-

ment 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.

LTC1289 TA01

LTC1289

1N4148

10

µF

–

+

10

Ω

1/4 LTC1079

+3V

–3V

TO AND

FROM

MPU

+

22

µF

TANTALUM

1N4148

10k

+

LT1004-1.2

0.1

µF

22

µF

1N5817

CH0

CH1

CH2

CH3

CH4

CH5

CH6

CH7

COM

DGND

ACLK

SCLK

CS

AGND

BOOST

GND

OSC

LV

LTC1044

10

µF

+

22

µF

–3V

3V

LITHIUM

FOR OVERVOLTAGE PROTECTION ON

ONLY ONE CHANNEL LIMIT THE INPUT

CURRENT TO 15mA. FOR MORE THAN

ONE CHANNEL LIMIT THE INPUT

CURRENT TO 7mA PER CHANNEL AND

28mA FOR ALL CHANNELS.

CONVERSION RESULTS ARE NOT VALID

WHEN THE SELECTED OR ANY OTHER

–

DESCRIPTIO

FEATURES

TYPICAL APPLICATIO

, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.

LTCMOS is a trademark of Linear Technology Corporation. All other trademarks are the

property of their respective owners.

APPLICATIO S