General Description

The TC7106A and TC7107A 3-1/2 digit direct display drive analog-to-digital converters allow existing 7106/ 7107 based systems to be upgraded. Each device has a precision reference with a 20ppm/°C max temperature coefficient. This represents a 4 to 7 times improvement over similar 3-1/2 digit converters. Existing 7106 and 7107 based systems may be upgraded without changing external passive component values. The TC7107A drives common anode light emitting diode (LED) displays directly with 8mA per segment. A low cost, high resolution indicating meter requires only a display, four resistors, and four capacitors.The TC7106A low power drain and 9V battery operation make it suitable for portable applications.

The TC7106A/TC7107A reduces linearity error to less than 1 count. Rollover error – the difference in readings for equal magnitude, but opposite polarity input signals, is below ±1 count. High impedance differential inputs offer 1pA leakage current and a 1012Ω input impedance. The differential reference input allows ratiometric measurements for ohms or bridge transducer measurements. The 15µVP–P noise performance ensures a “rock solid” reading. The auto-zero cycle ensures a zero display reading with a zero volts input. 

Features 

• Internal Reference with Low Temperature Drift - TC7106/7: 80ppm/°C Typical - TC7106A/7A: 20ppm/°C Typical 

• Drives LCD (TC7106) or LED (TC7107) Display Directly 

• Zero Reading with Zero Input 

• Low Noise for Stable Display 

• Auto-Zero Cycle Eliminates Need for Zero Adjustment 

• True Polarity Indication for Precision Null Applications 

• Convenient 9V Battery Operation (TC7106A) 

• High Impedance CMOS Differential Inputs: 1012Ω 

• Differential Reference Inputs Simplify Ratiometric Measurements 

• Low Power Operation: 10mW 

Applications 

• Thermometry 

• Bridge Readouts: Strain Gauges, Load Cells, Null Detectors 

• Digital Meters: Voltage/Current/Ohms/Power, pH 

• Digital Scales, Process Monitors 

• Portable Instrumentation

Feature