TC7109A

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 Overrange Indication
Sign Magnitude Coding Format
True Differential Signal Input and Differential Reference Input
Low Noise ............................................ 15 mVP-P Typ
Input Current .............................................. 1 pA Typ
No Zero Adjustment Needed
TTL-Compatible, Byte-Organized Tri-State Outputs
UART Handshake Mode for Simple Serial Data Transmission




Pinout






Specifications

Positive Supply Voltage (GND to V+) ..................... +6.2V
Negative Supply voltage (GND to V) ....................... 9V
Analog Input Voltage (Low to High) (Note 1) ....... V+ to V
Reference Input Voltage (Low to High (Note 1) .. V+ to V
Digital Input Voltage (Pins 227) (Note 2) .. GND 0.3V
Power Dissipation, TA < 70°C, (Note 3)
CerDIP .................................................................. 2.29W
Plastic DIP ............................................................. 1.23W
PLCC ...................................................................... 1.23W
PQFP ...................................................................... 1.00W
Operating Temperature Range
Plastic Package (C) ....................................0°C to +70°C
Ceramic Package (I) ...........................  25°C to +85°C
(M) ...................  55°C to +125°C
Storage Temperature Range .......... ... 65°C to +150°C
Lead Temperature (Soldering, 10 sec) ................ +300°C

Parameter Name	Value
Input Voltage Range (V)	Vss + 1.5 to Vdd - 1.5
Sampling Rate	2 to 10
Programmable resolution/conversion time	No
Input Range	Yes
Input Channels	1
Charge pump (-V) output pin	No
Resolution	12 bits plus sign bit
Sampling Rate (Conv/sec)	2 to 10
Interface	Serial Port
Supply Voltage Max (V)	5.5

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 VOH source current TC7109A has features that make it an attractive per-channel alternative to analog multiplexing for many data acquisition applications. These features include typical input bias current of 1pA drift of less than 1mV/°C, input noise typically 15mVP-P, and auto-zero. True differential input and reference allow measurement of bridge-type transducers such as load cells, strain gauges, and temperature transducers.

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 VOH source current TC7109A has features that make it an attractive per-channel alternative to analog multiplexing for many data acquisition applications. These features include typical input bias current of 1pA, drift of less than 1 V/°C, input noise typically 15 VPP,and auto-zero. True differential input and reference 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 enables 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 conversion 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 overrange recovery performance and higher output drive capability than the original TC7109.All new (or existing)designs should specify the TC7109A wherever possible.