Analog Devices Inc./Maxim Integrated MAX9645EUK+T

Overview

MAX9645EUK+T from Maxim Integrated is a nanoPower inverting comparator with internal 0.2V precision reference, open-drain output, and 5-pin SOT23 package. It operates from 1.0V to 5.5V supply, draws ≤700nA supply current, features -0.3V to +5.5V input voltage range independent of VCC, and delivers 15µs propagation delay across -40°C to +85°C - enabling ultra-low-power voltage monitoring in space-constrained portable medical devices.

For engineers reviewing the MAX9645EUK+T datasheet, MAX9645EUK+T pinout, MAX9645EUK+T application, or MAX9645EUK+T equivalent, this page provides verified technical context, real-world design meaning for key specs, validated pin functions, confirmed alternative parts with documented functional differences, and supply-chain support details specific to OEM and embedded design programs.

Technical Context

The MAX9645EUK+T implements an inverting comparator architecture with internally trimmed 0.2V reference (±1% at +25°C, ±3.5% over temperature), enabling precise low-voltage threshold detection without external components. Its input stage maintains high impedance even when VCC = 0V, supporting flexible power-gating schemes in battery-powered systems.

It uses an open-drain output requiring external pullup, allowing level-shifting between logic domains - e.g., interfacing a 1.2V microcontroller I/O with a 3.3V system bus. Propagation delay remains stable (15µs typ) across input overdrive ≥100mV and temperature (-40°C to +85°C), with RF-immune internal filtering.

Key Specifications

Pinout & Package

MAX9645EUK+T is housed in a RoHS-compliant 5-pin SOT23 package (package code U5+2), footprint compatible with industry-standard SOT23-5 land patterns (land pattern no. 90-0174). Height is 1.45mm max; thermal resistance θ_JA = 256°C/W.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar inverting comparator applications.

Compared with TLV3691IDBVR and MAX9063AXK+T, the MAX9645EUK+T uniquely combines inverting configuration, -0.3V input capability, and 0.2V reference in a production-qualified SOT23-5 package - making it the only option for space-constrained, ultra-low-power designs requiring direct sub-VCC threshold detection.

Availability

MAX9645EUK+T is available at Aetrix Electronics and suitable for portable medical devices, notebook computers, and electronic toys requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MAX9645EUK+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, mixed-signal, and power-management ICs for demanding industrial, medical, and portable applications.

The MAX964x family targets ultra-low-power, space-constrained systems needing integrated reference comparators - specifically engineered for battery-operated devices where every nanoamp and square millimeter matters.

FAQ

What is the input configuration of the MAX9645EUK+T?

The MAX9645EUK+T features an inverting input configuration: when the input voltage exceeds the internal 0.2V reference, the open-drain output asserts low; when input falls below 0.2V, the output floats high (requiring external pullup). This behavior is confirmed in Table 1 of the datasheet and distinguishes MAX9645EUK+T from noninverting variants MAX9644EUK+ and MAX9646EUK+.

Does the MAX9645EUK+T require an external reference voltage?

No, the MAX9645EUK+T does not require an external reference voltage. It integrates a factory-trimmed 0.2V internal reference with ±1% accuracy at +25°C and ±3.5% over temperature. This eliminates external resistors or reference ICs, reducing component count and PCB area - a key advantage confirmed in the General Description and Electrical Characteristics sections.

What is the maximum sink current capability of the MAX9645EUK+T output?

The MAX9645EUK+T open-drain output can sink up to 1.2mA while maintaining VOL ≤ 0.5V at VCC = 5.5V, per the Electrical Characteristics table. At lower supplies (e.g., VCC = 1.0V), it sinks 50µA with VOL ≤ 0.2V. These values define practical pullup resistor selection - for example, a 10kΩ pullup to 3.3V yields ~330µA sink current, well within specification.

Can the MAX9645EUK+T operate with input voltages below ground?

Yes, the MAX9645EUK+T supports input voltages as low as -0.3V relative to GND, independent of VCC. This is explicitly guaranteed in the Absolute Maximum Ratings and DC Characteristics tables. The architecture maintains high input impedance even at negative inputs, enabling direct sensing of bipolar signals or fault conditions in portable systems.

Is the MAX9645EUK+T pin-compatible with other parts in the MAX964x family?

Yes, the MAX9645EUK+T shares identical 5-pin SOT23 pinout with MAX9644EUK+ and MAX9646EUK+, as confirmed in the Pin Configuration diagram and Pin Description table. All three use pins 1 (VCC), 2/3 (GND), 4 (IN), and 5 (OUT) with identical functions - enabling layout reuse across inverting, noninverting, and push-pull variants in the same design.