LTC1094_15 Datasheet, PDF (1/32 Pages) Linear Technology – 1-, 2-, 6- and 8-Channel, 10-Bit Serial I/O Data Acquisition Systems

LTC1091/LTC1092
LTC1093/LTC1094
1-, 2-, 6- and 8-Channel, 10-Bit
Serial I/O Data Acquisition Systems
FEATURES
s _{Programmable Features}
– Unipolar/Bipolar Conversions
– Differential/Single-Ended Multiplexer
Configurations
s _{Sample-and-Holds}
s _{Single Supply 5V, 10V or ±5V Operation}
s _{Direct 3- or 4-Wire Interface to Most MPU Serial}
Ports and All MPU Parallel I/O Ports
s _{Analog Inputs Common Mode to Supply Rails}
s _{Resolution: 10 Bits}
s _{Total Unadjusted Error (A Grade): ±1LSB Over Temp}
s _{Fast Conversion Time: 20µs}
s _{Low Supply Current}
LTC1091: 3.5mA Max, 1.5mA Typ
LTC1092/LTC1093/LTC1094: 2.5mA Max, 1mA Typ
DESCRIPTIO
The LTC^®1091/LTC1092/LTC1093/LTC1094 10-bit data
acquisition systems are designed to provide complete
function, excellent accuracy and ease of use when digitiz-
ing analog data from a wide variety of signal sources and
transducers. Built around a 10-bit, switched capacitor,
successive approximation A/D core, these devices include
software configurable analog multiplexers and bipolar and
unipolar conversion modes as well as on-chip sample-
and-holds. On-chip serial ports allow efficient data trans-
fer to a wide range of microprocessors and microcontrol-
lers. These circuits can provide a complete data acquisi-
tion system in ratiometric applications or can be used with
an external reference in others.
The high impedance analog inputs and the ability to
operate with reduced spans (below 1V full scale) allow
direct connection to sensors and transducers in many
applications, eliminating the need for gain stages.
An efficient serial port communicates without external
hardware to most MPU serial ports and all MPU parallel
I/O ports allowing eight channels of data to be transmitted
over as few as three wires. This, coupled with low power
consumption, makes remote location possible and facili-
tates transmitting data through isolation barriers.
Temperature drift of offset, linearity and full-scale error
are all extremely low (1ppm/°C typically) allowing all
grades to be specified with offset and linearity errors of
±0.5LSB maximum over temperature. In addition, the A
grade devices are specified with full-scale error and total
unadjusted error (including the effects of offset, linearity
and full-scale errors) of ±1LSB maximum over tempera-
ture. The lower grade has a full-scale specification of
±2LSB for applications where full scale is adjustable or
less critical.
, LTC and LT are registered trademarks of Linear Technology Corporation.
TYPICAL APPLICATION
5V 4.7µF
ANALOG INPUT #1
0V TO 5V RANGE
ANALOG INPUT #2
0V TO 5V RANGE
1
CS
2
CH0
V_CC 8
(V_REF)
7
CLK
3
LTC1091
6
CH1
D_OUT
4
GND
5
D_IN
MPU
(e.g., 8051)
P1.4
P1.3
P1.2
SERIAL DATA LINK
1091 TA01
FOR 8051 CODE SEE
APPLICATIONS INFORMATION
SECTION
1.25
V_CC = 5V
1.00
0.75
0.50
0.25
0
0
1
2
3
4
5
REFERENCE VOLTAGE (V)
1091 TA02
1