Microchip TC7136CPL: A 3-1/2 Digit Single-Chip A/D Converter with Display Drivers

The Microchip TC7136CPL is a highly integrated, high-performance analog-to-digital (A/D) converter designed specifically for precision measurement applications. As a member of the renowned 71xx family, this IC combines a complete A/D converter, reference, clock, and display drivers into a single 40-pin package, making it an ideal solution for building accurate digital panel meters, multimeters, and other instrumentation.

At its core, the device employs a dual-slope integration conversion method. This technique is celebrated for its exceptional ability to reject both 50Hz and 60Hz power line noise, ensuring stable and accurate readings even in electrically noisy environments. The integration process inherently averages out random noise, providing reliable performance critical for sensitive measurements.

A key feature of the TC7136CPL is its ability to directly drive liquid crystal displays (LCDs). It includes on-chip segment and backplane drivers, significantly reducing the need for external components and simplifying the overall design. The output is formatted for a standard 3-1/2 digit display, offering a maximum readout of ±1999 counts with automatic polarity and overrange indication.

The device operates with auto-zeroing, which minimizes offset drift errors over time and temperature, guaranteeing long-term measurement stability. Its design requires only a handful of passive components—a precision integrating capacitor, resistor, and a reference capacitor—to form a fully functional digital voltmeter. The on-chip voltage reference is typically set at 3.0V, but can be easily adjusted for different input ranges.

Engineers value the TC7136CPL for its low power consumption, a trait that makes it exceptionally well-suited for portable, battery-operated equipment. Its robustness, ease of use, and high level of integration have cemented its status as a classic and enduring solution in the world of data acquisition and digital display.

ICGOODFIND: The Microchip TC7136CPL remains a cornerstone IC for embedded measurement systems, offering a complete, low-noise, and easy-to-implement analog-to-digital conversion solution with direct LCD drive capabilities.

Keywords:

Analog-to-Digital Converter (ADC)

Dual-Slope Integration

LCD Display Drivers

Noise Rejection

Low Power Consumption