The TC7107A 3½ digit LED direct-display drive analog-to-digital converters allow existing TC7107 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 3½ digit converters. Existing TC7107 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 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 10¹² Ohm input impedance. The differential reference input allows ratiometric measurements for ohms or bridge transducer measurements. The 15µVp-p noise performance guarantees a great reading. The auto-zero cycle guarantees a zero display reading with a zero-volts input.