Analog Devices Inc./Maxim Integrated ICL7665ACPA+

Overview

ICL7665ACPA+ from Maxim Integrated is a dual over/undervoltage microprocessor supervisor IC featuring two independently programmable voltage detectors, 2% VSET1 threshold accuracy at +25°C, 3µA typical quiescent current, and operation from 2.0V to 16V supply. It monitors voltages ≥1.3V using external resistor dividers and delivers open-drain N-channel OUT1/OUT2 and open-drain P-channel HYS1/HYS2 outputs for battery-powered µP reset and power-fail warning in portable instrumentation.

For engineers reviewing the ICL7665ACPA+ datasheet, ICL7665ACPA+ pinout, ICL7665ACPA+ application, or ICL7665ACPA+ equivalent, key selection criteria include its guaranteed 2% VSET1 accuracy over temperature, dual independent hysteresis control via HYST1/HYST2, low 3µA supply current enabling multi-year battery life, and compatibility with high-impedance resistor networks for precise trip-point programming without potentiometers.

Technical Context

The ICL7665ACPA+ integrates a precision 1.3V bandgap reference with two matched comparators and on-chip hysteresis control circuitry. Its dual comparator architecture enables simultaneous overvoltage (OUT1) and undervoltage (OUT2) detection with independent SET1/SET2 inputs and dedicated HYST1/HYST2 current-source outputs that actively pull toward V+ to set lower trip thresholds.

Each detector uses the same internal 1.3V reference but supports externally adjustable trip points via resistor dividers; hysteresis is implemented by feeding back HYSTx output current into the divider network, shifting the lower threshold while preserving upper threshold stability - a design optimized for noise immunity in brownout and power-fail monitoring.

Key Specifications

Pinout & Package

ICL7665ACPA+ is housed in an 8-pin plastic DIP package (0.300" width), RoHS-compliant and lead-free. Pin spacing follows JEDEC MS-001 standard with 0.100" pitch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLV809E33DBZR and MAX6326UT29D3+, the ICL7665ACPA+ uniquely delivers two fully independent, resistor-programmable voltage detectors with integrated hysteresis control outputs - a capability absent in both alternatives and essential for compact, low-power dual-rail supervision.

Availability

ICL7665ACPA+ is available at Aetrix Electronics and suitable for microprocessor voltage monitoring, battery backup switchover, and multi-rail power-fail warning requiring stable component supply across commercial temperature grades.

Supply support for ICL7665ACPA+ 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) is a fabless semiconductor company specializing in high-performance analog and mixed-signal ICs for power, sensing, and interface applications.

The ICL7665ACPA+ belongs to Maxim's legacy voltage supervisor product line, designed specifically for ultra-low-power, dual-threshold monitoring in battery-critical and industrial embedded systems where precision, simplicity, and long-term reliability are paramount.

FAQ

What is the guaranteed VSET1 threshold accuracy of the ICL7665ACPA+ over temperature?

The ICL7665ACPA+ guarantees ±2.5% VSET1 threshold accuracy across its full operating temperature range of 0°C to +70°C. This specification includes both initial tolerance and temperature drift (100ppm/°C typical), making it suitable for applications where calibrated trip points are required without external trimming. The ICL7665ACPA+ achieves this via laser-trimmed internal reference and matched comparator offsets - a key differentiator from standard-grade ICL7665C variants.

Can the ICL7665ACPA+ monitor voltages higher than its V+ supply?

Yes, the ICL7665ACPA+ can monitor input voltages significantly higher than its V+ supply using external resistor dividers on SET1 and SET2 pins. The device's input structure tolerates voltages up to (V+ + 0.3V) on SET pins, but the divider network isolates the IC from high-voltage rails. For example, a 24V rail can be safely monitored with a 10:1 divider, presenting only 2.4V to SET1 - well within the (GND – 0.3V) to (V+ + 0.3V) absolute maximum rating.

How does the HYST1 and HYST2 functionality work in the ICL7665ACPA+?

HYST1 and HYST2 are open-drain P-channel outputs referenced to V+. When their corresponding comparator trips (e.g., VSET1 > 1.3V), HYST1 sources current into the external resistor network, lowering the effective threshold for subsequent release - creating hysteresis. This eliminates external components like Schmitt triggers. The amount of hysteresis is set by resistor ratios (e.g., R31 in Figure 4), and HYST1/HYST2 allow independent hysteresis tuning per channel - a feature critical for noise-immune brownout detection in the ICL7665ACPA+.

What is the minimum supply voltage required for reliable operation of the ICL7665ACPA+?

The ICL7665ACPA+ requires a minimum supply voltage of 2.0V for guaranteed operation across its full 0°C to +70°C temperature range. Below 2.0V, comparator offset and reference stability degrade, potentially causing false trips. At 2.0V, the device draws only 2.5µA typical supply current and maintains full 2% VSET1 accuracy - enabling use in deeply discharged battery scenarios where other supervisors fail to operate.

Does the ICL7665ACPA+ support wire-OR connection of its outputs?

Yes, both OUT1 and OUT2 are open-drain N-channel outputs, making them inherently compatible with wire-OR configurations. When multiple ICL7665ACPA+ devices or other open-drain outputs share a common pull-up resistor, any device asserting LOW will drive the net LOW - ideal for generating consolidated "POWER OK" or "FAULT" signals in multi-supply systems. HYST1 and HYST2 are open-drain P-channel outputs referenced to V+, so they require connection to V+ (not GND) for proper wire-OR operation.