D Zero Reading for 0-V Input
D Precision Null Detection With True Polarity
D 1-pA Typical Input Current
D True Differential Input
D Multiplexed Binary-Coded-Decimal (BCD)
D Low Rollover Error: ± 1 Count Max
D Control Signals Allow Interfacing With
UARTs or Microprocessors
D Autoranging Capability With Over- and
D TTL-Compatible Outputs
D Second Source to Teledyne TSC7135,
Intersil ICL7135, Maxim ICL7135, and
D CMOS Technology
4 1/2ĆDIGIT PRECISION
SLAS074D − DECEMBER 1986 − REVISED SEPTEMBER 2003
DW OR N PACKAGE
VCC − 1
ANLG COMMON 3
INT OUT 4
AUTO ZERO 5
BUFF OUT 6
Cref − 7
Cref + 8
IN − 9
IN + 10
VCC + 11
28 UNDER RANGE
27 OVER RANGE
24 DGTL GND
The ICL7135C and TLC7135C converters are manufactured with Texas Instruments highly efficient CMOS
technology. These 4 1/2-digit, dual-slope-integrating, analog-to-digital converters (ADCs) are designed to
provide interfaces to both a microprocessor and a visual display. The digit-drive outputs D1 through D4 and
multiplexed binary-coded-decimal outputs B1, B2, B4, and B8 provide an interface for LED or LCD
decoder/drivers as well as microprocessors.
The ICL7135C and TLC7135C offer 50-ppm (one part in 20,000) resolution with a maximum linearity error of
one count. The zero error is less than 10 µV and zero drift is less than 0.5 µV/°C. Source-impedance errors are
minimized by low input current (less than 10 pA). Rollover error is limited to ± 1 count.
The BUSY, STROBE, RUN/HOLD, OVER RANGE, and UNDER RANGE control signals support
microprocessor-based measurement systems. The control signals also can support remote data acquisition
systems with data transfer through universal asynchronous receiver transmitters (UARTs).
The ICL7135C and TLC7135C are characterized for operation from 0°C to 70°C.
0°C to 70°C
Caution. These devices have limited built-in protection. The leads should be shorted together or the device placed in conductive foam
during storage or handlilng to prevent electrostatic damage to the MOS gates.
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
Copyright 1999−2003, Texas Instruments Incorporated
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