Analog Devices Inc./Maxim Integrated MAX6425UK17-T

Overview

MAX6425UK17-T from Maxim Integrated is a low-power microprocessor reset supervisor IC with open-drain active-low RESET output, 5-pin SOT23-5 package, factory-trimmed 1.665V reset threshold (suffix "17"), and capacitor-adjustable reset timeout period. It monitors VCC from 1.6V to 5V and guarantees valid reset assertion down to VCC = 1V, used in battery-powered controllers and portable medical instruments.

For engineers reviewing the MAX6425UK17-T datasheet, MAX6425UK17-T pinout, MAX6425UK17-T application, or MAX6425UK17-T equivalent, key selection criteria include its open-drain output compatibility with mixed-voltage systems, 1.6µA typical quiescent current, ±2.5% reset threshold accuracy over -40°C to +125°C, and SRT pin-based timeout adjustment via external capacitor.

Technical Context

The MAX6425UK17-T implements a precision voltage detector with laser-trimmed internal reference and hysteresis of 4×VTH (≈6.66mV). Its reset timeout is generated by a 240nA internal ramp current charging an external capacitor (CSRT) to a 0.65V threshold, yielding tRP = 2.73×10⁶ × CSRT + 275µs.

It features immunity to short VCC transients-e.g., a 100mV overdrive below VTH tolerates ≤50µs glitches-and ensures monotonic reset deassertion during power-up via controlled ramp release. The open-drain RESET output requires an external pullup resistor (10kΩ–100kΩ) to any supply up to 5.5V for logic-level flexibility.

Key Specifications

Pinout & Package

MAX6425UK17-T uses a 5-pin SOT23-5 package with exposed pad (not electrically connected), footprint per Maxim land pattern 90-0174. Pin 1 is SRT (Set Reset Timeout), Pin 2 is GND, Pin 3 is N.C. (Not Internally Connected), Pin 4 is VCC, and Pin 5 is RESET (open-drain active-low).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6425UK17-T, NCP302LSN33T1G offers lower cost but no timeout flexibility, while TPS3808G33DBVR achieves lower ICC and tighter timeout tolerance at the expense of pin count and capacitor-free design.

Availability

MAX6425UK17-T is available at Aetrix Electronics and suitable for portable medical monitors, battery-powered industrial controllers, and automotive body control modules requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6425UK17-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, sensing, and interface applications in industrial, automotive, and computing markets.

The MAX6421–MAX6426 family delivers ultra-low-power, capacitor-programmable reset supervision for space- and energy-constrained embedded systems where flexible timeout and multi-rail compatibility are essential.

FAQ

What is the exact reset threshold voltage of MAX6425UK17-T?

The MAX6425UK17-T has a factory-trimmed nominal reset threshold of 1.665V, with guaranteed tolerance of ±2.5% over the full -40°C to +125°C operating temperature range. This value is confirmed in Table 1 of the datasheet (suffix "17") and applies specifically to the MAX6425UK17-T, not the broader MAX6425 family.

How do I calculate the reset timeout capacitor for MAX6425UK17-T?

To set a desired reset timeout period (tRP) for MAX6425UK17-T, use the formula CSRT = (tRP − 275µs) / 2.73×10⁶, where tRP is in seconds and CSRT is in farads. For example, a 10ms timeout requires CSRT ≈ 3.58nF. Use low-leakage ceramic capacitors; avoid electrolytics or high-DA types.

Can MAX6425UK17-T drive a 5V microcontroller reset input?

Yes, MAX6425UK17-T can interface with a 5V µP reset input because its open-drain RESET output allows an external pullup resistor to 5V. When RESET is asserted, it sinks current to ground; when deasserted, the pullup defines the high level. Ensure the pullup value (e.g., 10kΩ) supplies sufficient current for the µP's input leakage.

Is MAX6425UK17-T pin-compatible with other SOT23-5 reset supervisors?

MAX6425UK17-T is pin-compatible with NCP300–NCP303, MC33464/MC33465, S807/S808/S809, and RN5VD series devices per the datasheet's ordering guide. Pin mapping (SRT/GND/N.C./VCC/RESET) matches these alternatives, enabling direct substitution where open-drain output and 1.665V threshold meet system requirements.

Does MAX6425UK17-T require a pullup resistor on the RESET pin?

Yes, MAX6425UK17-T requires an external pullup resistor on the RESET pin because it features an open-drain output. A 10kΩ to 100kΩ resistor to the target logic supply (e.g., 3.3V or 5V) is recommended. Without it, the RESET line floats and cannot achieve a defined logic-high state, risking unreliable µP initialization.