LTC1287 Datasheet, PDF (1/16 Pages) Linear Technology – 3V Single Chip 12-Bit Data Acquisition System

LTC1287
3V Single Chip 12-Bit
Data Acquisition System
FEATURES
s _{Single Supply 3.3V or ±3.3V Operation}
s _{Built-In Sample-and-Hold}
s _{Direct 3-Wire Interface to Most MPU Serial Ports and}
All MPU Parallel Ports
s _{30kHz Maximum Throughput Rate}
KEY SPECIFICATIO S
s _{Minimum Guaranteed Supply Voltage: 2.7V}
s _{Resolution: 12 Bits}
s _{Fast Conversion Time: 24µs Max Over Temp.}
s _{Low Supply Current: 1.0mA}
TYPICAL APPLICATI
s _{Battery-Powered Instruments}
s _{Data Logger}
s _{Data Acquisition Modules}
DESCRIPTIO
The LTC1287 is a 3V data acquisition component which
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^TM switched ca-
pacitor technology to perform a 12-bit unipolar, A/D
conversion. The differential input has an on-chip sample-
and-hold on the (+) input.
The serial I/O is designed to communicate without external
hardware to most MPU serial ports and all MPU parallel
I/O ports allowing data to be transmitted and received over
three wires. The low voltage operating capability and the
low power consumption of this device make it ideally
suited for battery applications. Given the ease of use, small
package size and the minimum number of interconnects
for I/O, the LTC1287 can be used for remote sensing
applications.
LTCMOS is a trademark of Linear Technology Corporation
3V Differential Input Data Acquisition System
22µF TANTALUM
INL with V_REF = 1.2V
1.0
DIFFERENTIAL INPUTS ₊
COMMON MODE RANGE
0V TO V_CC* _–
CS
V_CC
+IN
CLK
LTC1287
–IN
D_OUT
GND
V_REF
22µF ⁺
TANTALUM
3V
10k
LITHIUM
0.5
0
LT1004-1.2
–0.5
TO AND FROM MPU
* FOR OVERVOLTAGE PROTECTION, LIMIT THE INPUT CURRENT TO 15mA
PER PIN OR CLAMP THE INPUTS TO V_CC AND GND WITH 1N4148 DIODES.
CONVERSION RESULTS ARE NOT VALID WHEN THE SELECTED CHANNEL OR
OTHER CHANNEL IS OVERVOLTAGED (V_IN < GND OR V_IN > V_CC). SEE SECTION
ON OVERVOLTAGE PROTECTION IN THE APPLICATIONS INFORMATION.
1287 TA01
–1.0
0
512 1024 1536 2048 2560 3072 3584 4096
CODE
LTC1287 TA02
1