1

LTC1290

1290fe

, LTC and LT 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. Protected by U.S. Patents, including 5287525.

DESCRIPTIO

KEY SPECIFICATIO S

FEATURES

Single Chip 12-Bit Data

Acquisition System

12-Bit 8-Channel Sampling Data Acquisition System

CH0

CH1

CH2

CH3

CH4

CH5

CH6

CH7

COM

DGND

ACLK

SCLK

CS

AGND

LTC1290

DIFFERENTIAL INPUT (+)

±5V COMMON MODE RANGE (–)

•

•

•

•

•

•

1k

SINGLE-ENDED INPUT

0V TO 5V OR

±5V

±15V OVERVOLTAGE RANGE*

TO AND FROM

MICROPROCESSOR

0.1

µF

1N5817

–5V

22

µF

TANTALUM

1N5817

1N4148

4.7

µF

TANTALUM

1

µF

LT

5V

8V TO 40V

* FOR OVERVOLTAGE PROTECTION ON ONLY ONE CHANNEL LIMIT THE INPUT CURRENT TO 15mA. FOR OVERVOLTAGE PROTECTION

ON MORE THAN ONE CHANNEL LIMIT THE INPUT CURRENT TO 7mA PER CHANNEL AND 28mA FOR ALL CHANNELS. (SEE SECTION ON

OVERVOLTAGE PROTECTION IN THE APPLICATIONS INFORMATION SECTION.) CONVERSION RESULTS ARE NOT VALID WHEN THE SELECTED

1290 • TA01

+

+

The LTC

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

verter. It uses LTCMOS

to perform either 12-bit unipolar or 11-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. When the

LTC1290 is idle it can be powered down with a serial word

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.

– Unipolar/Bipolar Conversion

– Four Differential/Eight Single-Ended Inputs

– MSB- or LSB-First Data Sequence

– Variable Data Word Length

– Power Shutdown

■

Single Supply 5V or

±5V Operation

and All MPU Parallel Ports

■

50kHz Maximum Throughput Rate

µs Max Over Temp

TYPICAL APPLICATIO