GENERAL DESCRIPTION
The TC7126A is a 3-1/2 digit CMOS analog-to-digital
converter (ADC) containing all the active components nec
essary to construct a 0.05% resolution measurement sys
tem. Seven-segment decoders, digit and polarity drivers,
voltage reference, and clock circuit are integrated on-chip.
The TC7126A directly drives a liquid crystal display (LCD),
and includes a backplane driver.
A low-cost, high-resolution indicating meter requires
only a display, four resistors, and four capacitors. The
TC7126A's extremely low power drain and 9V battery
operation make it ideal for portable applications.

FEATURES
■ Low Temperature Drift Internal Reference
    TC7126 ....................................... 80 ppm/°C Typ
    TC7126A ..................................... 35 ppm/°C Typ
■ Guaranteed Zero Reading With Zero Input
■ Low Noise .................................................... 15 µVP-P
■ High Resolution .............................................. 0.05%
■ Low Input Leakage Current ...................... 1 pA Typ
                                                      10 pA Max
■ Precision Null Detectors With True Polarity at Zero
■ High-Impedance Differential Input
■ Convenient 9V Battery Operation With
    Low Power Dissipation ........................ 500 µW Typ
                                                  900 µW Max

TYPICAL APPLICATIONS
■ Thermometry
■ Bridge Readouts: Strain Gauges, Load Cells, Null Detectors
■ Digital Meters and Panel Meters
    — Voltage/Current/Ohms/Power, pH
■ Digital Scales, Process Monitors