Analog Devices Inc./Maxim Integrated ICL7665CSA+T

Overview

ICL7665CSA+T from Maxim Integrated is a dual over/undervoltage microprocessor supervisor IC with two independently programmable comparators, a precision 1.3V internal bandgap reference, open-drain N-channel OUT1/OUT2 outputs, and open-drain P-channel HYS1/HYS2 hysteresis outputs. It operates from 1.6V to 16V supply voltage, draws only 3µA typical quiescent current, and supports external trip-point programming for voltages ≥1.3V. It is used in battery-powered systems for low-battery detection and power-fail warning.

For engineers reviewing the ICL7665CSA+T datasheet, ICL7665CSA+T pinout, ICL7665CSA+T application, or ICL7665CSA+T equivalent, this page delivers verified technical context, real-world design meaning of specifications, validated pin functions, confirmed alternative parts with functional distinctions, and supply-chain support details specific to the ICL7665CSA+T SO-8 RoHS-compliant package.

Technical Context

The ICL7665CSA+T integrates a low-power CMOS 1.3V bandgap reference with two independent comparators, each driving one open-drain N-channel output (OUT1, OUT2) and one open-drain P-channel hysteresis output (HYST1, HYST2). Its comparator input bias current is <10nA, enabling use of high-impedance external resistor dividers for trip-point setting without accuracy degradation.

It features noninverting HYST1/HYST2 and inverting OUT1 (OUT2 is noninverting per truth table), with propagation delay of 75µs typical. The device supports three hysteresis implementation topologies - no-hysteresis, series-resistor hysteresis, and supply-referenced hysteresis - all relying on externally programmed resistive networks tied to SET1/SET2 pins.

Key Specifications

Pinout & Package

ICL7665CSA+T is housed in an 8-pin SOIC (Small Outline Integrated Circuit) 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+T and TPS3808G12DBVR, the ICL7665CSA+T uniquely provides two fully independent, resistor-programmable voltage detectors with dedicated hysteresis outputs in one SO-8 package - enabling compact, low-power dual-threshold supervision without timers or fixed thresholds.

Availability

ICL7665CSA+T is available at Aetrix Electronics and suitable for microprocessor voltage monitoring, low-battery detection, and power-fail warning applications requiring stable component supply across industrial, medical, and portable electronics programs.

Supply support for ICL7665CSA+T 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 for demanding environments.

The ICL7665CSA+T belongs to Maxim's microprocessor supervisor product line, engineered specifically for dual-threshold voltage monitoring in battery-constrained and fault-critical systems where minimal quiescent current and flexible trip-point configuration are essential.

FAQ

What is the function of the HYST1 and HYST2 pins on the ICL7665CSA+T?

The HYST1 and HYST2 pins on the ICL7665CSA+T are open-drain P-channel outputs that source current from V+ when their respective comparator inputs (SET1 or SET2) exceed 1.3V. They enable external hysteresis implementation by feeding back into the voltage divider network - for example, adding R31 between HYST1 and SET1 raises the lower trip point without affecting the upper trip point, preventing chatter near threshold. This functionality is intrinsic to the ICL7665CSA+T architecture and does not require additional components beyond resistors.

Can the ICL7665CSA+T monitor voltages higher than its V+ supply?

Yes - the ICL7665CSA+T can monitor input voltages significantly higher than its V+ supply using external resistor dividers on SET1 and SET2. The device's input structure allows SET pin voltages from (GND − 0.3V) to (V+ + 0.3V), but the resistive divider scales high-voltage signals (e.g., 24V, 48V, or hundreds of volts) down to ≤1.3V at the SET pin. This capability is explicitly confirmed in the General Description and Typical Operating Circuit sections of the official datasheet for the ICL7665CSA+T.

What is the difference between ICL7665CSA+T and ICL7665ACSA+T?

The ICL7665ACSA+T is the improved version of the ICL7665CSA+T, featuring 2% threshold accuracy at +25°C for V_SET1 and guaranteed performance over temperature (±2.5% max V_SET variation from −40°C to +85°C). In contrast, the base ICL7665CSA+T has looser initial tolerance (±11.5% for V_SET1) and higher tempco (100ppm/°C). Both share identical pinout, package (SO-8), and functional architecture - the "A" suffix denotes enhanced voltage reference precision in the ICL7665ACSA+T.

Does the ICL7665CSA+T require external pull-up resistors on its outputs?

Yes - the ICL7665CSA+T's OUT1, OUT2, HYST1, and HYST2 pins are all open-drain outputs and require external pull-up resistors to define logic-high states. For OUT1/OUT2 (N-channel sinks), pull-ups connect to V_CC of the driven logic (e.g., 3.3V or 5V). For HYST1/HYST2 (P-channel sources), pull-downs are not used; instead, they are connected through resistors to SET1/SET2 to inject hysteresis current. This pull-up requirement is inherent to the ICL7665CSA+T's output stage design and is documented in the Pin Configurations and Detailed Description sections.

Is the ICL7665CSA+T compatible with lead-free PCB assembly processes?

Yes - the "+T" suffix in ICL7665CSA+T indicates a lead-free, RoHS-compliant SOIC package, qualified for standard Pb-free reflow profiles (J-STD-020). The device's maximum lead temperature rating is +300°C for 10 seconds, matching IPC/JEDEC specifications for lead-free soldering. This compliance is explicitly noted in the Ordering Information table and Absolute Maximum Ratings section of the official ICL7665CSA+T datasheet.