Analog Devices Inc./Maxim Integrated ICL7665EPA

Overview

ICL7665EPA from Maxim Integrated is a dual over/undervoltage monitor IC for microprocessor supervision, featuring two independently programmable voltage detectors with 1.3V internal reference, 3µA typical supply current, ±5mV trip voltage difference between SET1 and SET2, and operation from 1.6V to 16V supply across –40°C to +85°C. It enables battery-backed memory protection in portable instrumentation.

For engineers reviewing the ICL7665EPA datasheet, ICL7665EPA pinout, ICL7665EPA application, or ICL7665EPA equivalent, this device supports precision low-power voltage monitoring in battery-powered systems, power-fail detection, brownout warning, and dual-threshold alarm generation without external reference components.

Technical Context

The ICL7665EPA integrates a 1.3V bandgap reference, two high-impedance comparators (input bias <10nA), open-drain N-channel OUT1/OUT2 outputs, and open-drain P-channel HYS1/HYS2 hysteresis outputs - all in monolithic CMOS. Its comparator trip point is set when VSET = 1.3V, enabling resistor-programmed thresholds above 1.3V.

Each detector supports externally adjustable hysteresis via dedicated HYSTx terminals; hysteresis only affects the lower trip point, with upper/lower thresholds determined by resistor divider ratios. Propagation delay is typically 75µs, and output saturation voltages are specified at 0.10V (V+ = 5V, IOUT = 2mA) for OUT1 and –0.43V (V+ = 5V, IHYST = –0.2mA) for HYST2.

Key Specifications

Pinout & Package

ICL7665EPA is housed in an 8-pin plastic DIP (dual in-line package) with 0.3-inch width, RoHS-compliant lead finish, and through-hole mounting. Pin 1 is OUT1; pin numbering follows standard DIP convention with notch orientation as shown in Maxim's top-view diagram.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-threshold voltage monitoring applications.

Compared with TLV809E and MAX6326, the ICL7665EPA uniquely supports fully independent, resistor-programmed over/undervoltage thresholds with integrated hysteresis control - essential for adaptive power monitoring in variable-voltage or multi-supply systems.

Availability

ICL7665EPA is available at Aetrix Electronics and suitable for industrial PLCs, portable medical devices, and battery-backed data loggers requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for ICL7665EPA includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Maxim Integrated (now part of Analog Devices) designs precision analog and mixed-signal ICs for power management, sensing, and interface applications, with emphasis on low-power, high-reliability solutions.

The ICL7665EPA belongs to Maxim's microprocessor supervisory product line, engineered specifically for robust voltage monitoring in battery-constrained and industrial environments where programmability, low quiescent current, and wide supply range are mandatory.

FAQ

What is the operating temperature range of the ICL7665EPA?

The ICL7665EPA is rated for operation from –40°C to +85°C, making it suitable for industrial control, automotive body electronics, and outdoor instrumentation where ambient conditions exceed commercial-grade limits. This rating is confirmed in Maxim's Ordering Information table and applies specifically to the "E" grade suffix in ICL7665EPA.

How does the ICL7665EPA achieve programmable voltage thresholds?

The ICL7665EPA uses its internal 1.3V reference as a comparator trip anchor: when the voltage at SET1 or SET2 equals 1.3V, the corresponding output toggles. External resistor dividers scale the monitored voltage down to 1.3V at the desired trip point - e.g., a 5.0V rail uses R1/R2 = 2.85:1 to yield 1.3V at SET1. The ICL7665EPA's <10nA input bias ensures minimal divider error.

Can the ICL7665EPA monitor voltages higher than its 16V supply rail?

Yes - the ICL7665EPA can monitor input voltages up to several hundred volts using high-value resistor dividers at SET1/SET2, while operating from a separate 1.6V–16V V+ supply. The absolute maximum rating for SET1/SET2 is (GND – 0.3V) to (V+ + 0.3V), so external protection (e.g., clamping diodes or series resistors limiting current to ≤500µA) is required when inputs exceed V+.

What is the purpose of the HYST1 and HYST2 pins on the ICL7665EPA?

HYST1 and HYST2 are open-drain P-channel outputs that source current from V+ when their respective comparator trips. They enable active hysteresis: connecting HYST1 to the SET1 divider network raises the effective lower trip point, preventing output oscillation near threshold due to noise. Unlike passive RC hysteresis, this method provides precise, temperature-stable hysteresis control without additional components.

Is the ICL7665EPA pin-compatible with the ICL7665CPA or ICL7665ACSA?

No - while all ICL7665 variants share identical pinout and functionality, the ICL7665EPA (–40°C to +85°C, plastic DIP) is not pin-compatible with SO-package versions like ICL7665ACSA due to different physical packages. Within the DIP family (e.g., ICL7665CPA, ICL7665EPA), pinout is identical, but temperature grade and threshold accuracy differ: ICL7665EPA has ±50mV VSET tolerance vs. ±25mV for ICL7665A-grade parts.