2002-2012 Microchip Technology Inc. DS21456D-page 1
TC7109/A
Features:
• Zero Integrator Cycle for Fast Recovery from
Input Overloads
• Eliminates Cross-Talk in Multiplexed Systems
• 12-Bit Plus Sign Integrating A/D Converter with
Over Range Indication
• Sign Magnitude Coding Format
• True Differential Signal Input and Differential
Reference Input
• Low Noise: 15V
P-P
Typ.
• Input Current: 1pA Typ.
• No Zero Adjustment needed
• TTL Compatible, Byte Organized Tri-State
Outputs
• UART Handshake Mode for simple Serial Data
Transmissions
Device Selection Table
*The “A” version has a higher I
OUT
on the digital lines.
General Description:
The TC7109A is a 12-bit plus sign, CMOS low power
Analog-to-Digital Converter (ADC). Only eight passive
components and a crystal are required to form a
complete dual slope integrating ADC.
The improved V
OH
source current and other TC7109A
features make it an attractive per-channel alternative to
analog multiplexing for many data acquisition applica-
tions. These features include typical input bias current
of 1pA, drift of less than 1V/°C, input noise typically
15V
P-P
, and auto-zero. True differential input and ref-
erence allow measurement of bridge type transducers,
such as load cells, strain gauges and temperature
transducers.
The TC7109A provides a versatile digital interface. In
the Direct mode, Chip Select and HIGH
/LOW byte
enable control parallel bus interface. In the Handshake
mode, the TC7109A will operate with industry standard
UARTs in controlling serial data transmission – ideal for
remote data logging. Control and monitoring of conver-
sion timing is provided by the RUN/HOLD
input and
Status output.
For applications requiring more resolution, see the
TC500, 15-bit plus sign ADC data sheet. The TC7109A
has improved over range recovery performance and
higher output drive capability than the original TC7109.
All new (or existing) designs should specify the
TC7109A wherever possible.
Part Number
(TC7109X)*
Package
Temperature
Range
TC7109CKW 44-Pin PQFP 0°C to +70°C
TC7109CLW 44-Pin PLCC 0°C to +70°C
TC7109CPL 40-Pin PDIP 0°C to +70°C
TC7109IJL 40-Pin CERDIP -25°C to +85°C
12-Bit A-Compatible Analog-to-Digital Converters
