ICL7137CMH+D

ADCs/DACs - Special Purpose Overview

The ICL7137CMH+D is a low-power, 3½-digit analog-to-digital converter (ADC) manufactured by Analog Devices Inc./Maxim Integrated. It integrates a dual-slope integrating ADC with a direct LCD driver interface, eliminating the need for external multiplexers or decoders. The device operates on a single supply voltage and features an internal clock and reference. Key electrical parameters include a resolution of 3½ digits (2000 counts), a typical conversion rate of 3 conversions per second, and a maximum input voltage range of ±2V. It is housed in a 44-lead MQFP surface-mount package.

ADCs/DACs - Special Purpose Feature Summary

• Integrates 3½-digit dual-slope ADC with direct LCD segment driver outputs
• Requires only one external capacitor for full-scale calibration
• Operates from a single power supply (typically +5V)
• Includes internal clock oscillator and precision voltage reference

ADCs/DACs - Special Purpose Applications

• Digital panel meters
• Battery-powered instrumentation
• Portable test equipment
• Industrial process control displays

ADCs/DACs - Special Purpose Procurement Notes

Verify the specific suffix '+D' against the manufacturer's current datasheet to confirm pinout compatibility and RoHS status. Ensure the 44-MQFP package dimensions match the PCB footprint design. Check for moisture sensitivity level (MSL) requirements if the component has been stored for extended periods prior to reflow soldering.

ADCs/DACs - Special Purpose Selection Notes

Select this component when a complete ADC solution with integrated display driving is required to minimize board space and component count. Compare with the ICL7136 if LED display driving is needed instead of LCD. Verify that the single-supply operation aligns with the system power architecture and that the 3½-digit resolution meets the measurement accuracy requirements.

ADCs/DACs - Special Purpose Part Context

This part belongs to the ICL713x family of integrating ADCs, widely used in digital multimeters and industrial controls. The ICL7137 variant specifically targets LCD applications with its built-in driver capability, distinguishing it from the ICL7135/7136 which require external drivers for LEDs or other displays. It represents a mature CMOS technology designed for low-cost, high-reliability measurements.

ADCs/DACs - Special Purpose Replacement Considerations

Direct substitutes include the TC7137 series from Microchip/TelCom. Cross-reference pinouts carefully as some compatible parts may have different pin assignments for the LCD segments. Verify that alternative sources offer the same 44-MQFP package and electrical specifications.