Analog Devices Inc./Maxim Integrated ICL7665BCSA

Overview

ICL7665BCSA 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 10V supply. It is used in battery backup switching and low-battery detection circuits where ultra-low quiescent current and external resistor-programmable thresholds are required.

For engineers reviewing the ICL7665BCSA datasheet, ICL7665BCSA pinout, ICL7665BCSA application, or ICL7665BCSA equivalent, key selection considerations include its 8-pin SO package, open-drain N-channel OUT1/OUT2 outputs with 25mA sink capability, P-channel hysteresis outputs (HYST1/HYST2), 100ppm/°C VSET temperature coefficient, and compatibility with high-impedance external resistor networks for trip point configuration.

Technical Context

The ICL7665BCSA integrates a precision 1.3V bandgap reference with two independent comparators and on-board hysteresis circuitry. Its dual open-drain outputs-OUT1 and OUT2-are N-channel sinks referenced to GND, while HYST1 and HYST2 are P-channel sources tied to V+. Each detector's trip point is set externally via resistor dividers connected to SET1 and SET2 pins.

Propagation delay is typically 75µs, and input bias current is below 10nA, enabling use of MΩ-range resistors without accuracy degradation. The device supports monitoring of voltages from 1.3V up to several hundred volts using appropriate external scaling networks, with hysteresis programmable per channel via HYSTx terminals.

Key Specifications

Pinout & Package

ICL7665BCSA is housed in an 8-pin SO (Small Outline) package, RoHS-compliant and lead-free, with standard 1.27mm pitch and 5.0mm × 4.0mm body dimensions.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6326US29D3+ and TLV809E29DBZR, the ICL7665BCSA uniquely supports two fully independent, resistor-programmable voltage detection channels with integrated hysteresis outputs-enabling compact, flexible supervision of multiple rails without external comparators or timing components.

Availability

ICL7665BCSA is available at Aetrix Electronics and suitable for microprocessor voltage monitoring, low-battery detection, battery backup switching, power-fail warning, and power-supply fault monitoring requiring stable component supply and long-term industrial availability.

Supply support for ICL7665BCSA 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, mixed-signal, and power management ICs for industrial, automotive, and communications applications.

The ICL7665BCSA belongs to Maxim's microprocessor supervisory product line, engineered specifically for ultra-low-power, dual-threshold voltage monitoring in battery-critical and safety-sensitive embedded systems.

FAQ

What is the supply voltage range for the ICL7665BCSA?

The ICL7665BCSA operates from a supply voltage (V+) of 1.6V to 10V. This range is specified for the ICL7665B grade per the Electrical Characteristics table. Absolute maximum rating is 18V, but sustained operation above 10V violates the ICL7665B specification and may impact accuracy or reliability. The ICL7665BCSA must be powered within this 1.6V–10V window to ensure guaranteed performance across its 0°C to +70°C temperature range.

How does the ICL7665BCSA implement hysteresis?

The ICL7665BCSA implements hysteresis using dedicated P-channel open-drain outputs (HYST1 and HYST2) tied to V+. When a comparator trips, its corresponding HYSTx pin sources current into the external resistor network connected to SETx, shifting the effective threshold downward. This creates a voltage difference between upper and lower trip points-typically configured via R31/R32 resistors in standard application circuits. Unlike internal hysteresis, this architecture allows full user control over hysteresis magnitude per channel.

Can the ICL7665BCSA monitor voltages higher than its supply voltage?

Yes, the ICL7665BCSA can monitor input voltages significantly higher than its V+ supply-up to several hundred volts-using external resistor dividers connected to SET1 and SET2. The internal comparators reference only the 1.3V bandgap, so the external network scales the monitored voltage down to fit within the 1.3V threshold window. Input leakage is under 10nA, permitting high-impedance dividers that minimize loading on the source being monitored.

What are the output drive capabilities of ICL7665BCSA OUT1 and OUT2?

OUT1 and OUT2 are open-drain N-channel outputs capable of sinking up to 25mA each at V+ = 5V, with saturation voltage as low as 0.10V at 2mA. They cannot source current. To interface with TTL or CMOS logic, an external pull-up resistor to V+ or another rail is required. Their inverting behavior means OUTx goes low when the respective SETx voltage exceeds the 1.3V internal reference.

Is the ICL7665BCSA pin-compatible with other ICL7665 variants?

Yes, the ICL7665BCSA shares identical pinout and package footprint with all other ICL7665 variants in the 8-pin SO package-including ICL7665CSA, ICL7665ACSA, and ICL7665BCSA-and is also pin-compatible with the 8-pin DIP and CERDIP versions. Differences lie solely in electrical specifications (e.g., ICL7665A offers 2% VSET1 accuracy; ICL7665B specifies 1.6V–10V V+ range), not physical layout or connectivity.