ICL7139CM44

ADCs/DACs - Special Purpose Overview

The ICL7139CM44 is a low-power, 3½-digit analog-to-digital converter (ADC) manufactured by Harris Corporation. It features an integrated multiplexed input stage and a built-in LED display driver, eliminating the need for external scanning circuitry. The device operates on a single supply voltage and includes a high-impedance differential input amplifier with programmable gain. Key electrical characteristics include a typical conversion rate of 2 conversions per second and a power supply current of approximately 60 µA. It is housed in a 44-pin plastic DIP package.

ADCs/DACs - Special Purpose Feature Summary

• Integrated 3½-digit ADC with internal clock and reference
• Built-in LED display driver for direct segment driving
• Single-supply operation with low power consumption
• High-impedance differential input amplifier

ADCs/DACs - Special Purpose Applications

• Digital panel meters
• Industrial process control instrumentation
• Portable battery-powered measurement devices

ADCs/DACs - Special Purpose Procurement Notes

Verify the manufacturer origin, as the ICL7139 series was originally developed by Intersil and later acquired by Harris Semiconductor, which was subsequently acquired by Renesas Electronics. Confirm that the 'Harris' branding aligns with legacy inventory or specific contract manufacturing agreements. Ensure the CM44 suffix corresponds to the correct 44-pin plastic DIP package variant.

ADCs/DACs - Special Purpose Selection Notes

Select this component when a complete 3½-digit digitizing solution with direct LED output is required to minimize board space and component count. Compare against modern sigma-delta ADCs if higher resolution or digital interfaces are needed. Verify that the single-supply voltage range matches the system's power architecture and that the 2 Hz update rate meets application timing requirements.

ADCs/DACs - Special Purpose Part Context

The ICL7139 belongs to the broader family of 3½-digit ADCs, sharing architectural similarities with the ICL7106 and ICL7135 but adding integrated display drivers. This integration simplifies design for standalone indicator applications. The part represents a legacy technology node from the era of dedicated mixed-signal ASICs before microcontrollers became sufficiently powerful and cost-effective for such tasks.

ADCs/DACs - Special Purpose Replacement Considerations

Direct pin-compatible replacements may be limited due to the proprietary display driver integration. Consider the ICL7135 if external display scanning is acceptable, or modern microcontroller-based solutions for flexibility. Verify package compatibility and thermal characteristics when substituting.