TC7109/A
12-Bit
μA-Compatible
Analog-to-Digital Converters
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: 15μV
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
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 1μV/°C, input noise typically
15μV
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.
Device Selection Table
Part Number
(TC7109X)*
TC7109CKW
TC7109CLW
TC7109CPL
TC7109IJL
Package
44-Pin PQFP
44-Pin PLCC
40-Pin PDIP
40-Pin CERDIP
Temperature
Range
0°C to +70°C
0°C to +70°C
0°C to +70°C
-25°C to +85°C
*The “A” version has a higher I
OUT
on the digital lines.
©
2006 Microchip Technology Inc.
DS21456C-page 1
MICROCHIP [ MICROCHIP TECHNOLOGY ]
