TC7126 Datasheet | TelCom

1 TC7126 TC7126A 3-1/2 DIGIT ANALOG-TO-DIGITAL CONVERTERS Features s 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 2 3 4 5 6 7 GENERAL DESCRIPTION The TC7126A is a 3-1/2 digit CMOS analog-to-digital converter (ADC) containing all the active ponents necessary to construct a 0.05% resolution measurement system. 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. The TC7126A reduces linearity error to less than 1 count. Roll-over error (the difference in readings for equal magnitude but opposite polarity input signals) is below ±1 count. High-impedance differential inputs offer 1 pA leakage current and a 1012Ω input impedance. The 15 µVP-P noise performance guarantees a "rock solid" reading, and the auto-zero cycle guarantees a zero display reading with a 0V input. The TC7126A Features a precision, low-drift internal voltage reference and is functionally...