Analog Devices Inc./Maxim Integrated MAX6418UK23

Overview

MAX6418UK23 from Maxim Integrated is a low-power microprocessor reset supervisor IC with capacitor-adjustable reset timeout, monitoring VCC from 1.6V to 5V and asserting an active-low open-drain RESET output when supply voltage falls below 2.313V (±2.5% over temperature). It features 1.6µA typical quiescent current, guaranteed reset validity down to VCC = 1V, and operates in -40°C to +125°C industrial/automotive environments. Used for brownout protection in battery-powered controllers and embedded systems.

For engineers reviewing the MAX6418UK23 datasheet, MAX6418UK23 pinout, MAX6418UK23 application, or MAX6418UK23 equivalent, key selection criteria include its factory-trimmed 2.313V reset threshold, SOT23-5 open-drain output architecture, capacitor-programmable timeout (275µs base + 2.73×10⁶·CSRT), and immunity to sub-50µs VCC transients at 100mV overdrive - critical for reliable µP initialization in noisy power rails.

Technical Context

The MAX6418UK23 implements a precision bandgap-based voltage detector with laser-trimmed resistors to set its 2.313V reset threshold, maintaining ±2.5% accuracy across -40°C to +125°C. Its internal 240nA current source charges an external capacitor on the SRT pin, generating a linear ramp to a 0.65V internal reference to define the reset timeout period.

It uses open-drain RESET output logic compatible with mixed-voltage systems (pullup to 0–5.5V), supports wired-OR reset configurations, and guarantees valid output states down to VCC = 1V. The device is immune to short negative-going VCC transients ≤50µs when overdriven by 100mV below threshold - a key reliability feature for automotive and portable applications.

Key Specifications

Pinout & Package

MAX6418UK23 is housed in a 5-pin SOT23-5 package (package code U5+2), with exposed pad not connected internally. Pin 1 is VCC, Pin 2 is GND, Pin 3 is SRT (capacitor-adjustable timeout input), Pin 4 is RESET (open-drain output), and Pin 5 is NC (not internally connected, may be tied to GND).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar microprocessor reset supervision applications.

Compared with NCP302LSN23T1G and TLV809E23DBZR, MAX6418UK23 uniquely delivers factory-trimmed 2.313V accuracy combined with externally adjustable timeout - enabling precise adaptation to diverse µP reset timing requirements without sacrificing temperature stability or noise immunity.

Availability

MAX6418UK23 is available at Aetrix Electronics and suitable for battery-powered controllers, automotive body electronics, and medical infusion pumps requiring stable component supply, long-lifecycle support, and AEC-Q200-aligned qualification.

Supply support for MAX6418UK23 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 semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, automotive, and computing applications.

The MAX6421–MAX6426 family - including MAX6418UK23 - was designed specifically for ultra-low-power, capacitor-programmable reset supervision in harsh environments where precision voltage monitoring and glitch immunity are mandatory.

FAQ

What is the exact reset threshold voltage of MAX6418UK23 and how stable is it over temperature?

The MAX6418UK23 has a factory-trimmed nominal reset threshold of 2.313V, with guaranteed accuracy of ±2.5% over the full -40°C to +125°C operating range. This stability is achieved using laser-trimmed resistors and a precision bandgap reference, ensuring consistent brownout detection without external calibration - critical for automotive and industrial applications where ambient temperature varies widely.

How do I calculate the external capacitor value needed for a specific reset timeout period with MAX6418UK23?

Use the formula CSRT = (tRP − 275µs) / 2.73×10⁶, where tRP is the desired timeout in seconds and CSRT is the capacitor value in farads. For example, a 100ms timeout requires CSRT ≈ 36.5nF. Use low-leakage ceramic capacitors (X7R/C0G) with <10nA leakage; avoid electrolytics or high-K dielectrics that introduce timing drift.

Can MAX6418UK23 drive a reset input directly, or does it require external components?

MAX6418UK23 requires an external pullup resistor on its open-drain RESET pin - typically 10kΩ to 100kΩ - to the target µP's logic supply (0–5.5V). This enables level-shifting and wired-OR capability. No additional drivers or buffers are needed, but a pulldown resistor (e.g., 100kΩ) is recommended if RESET validity down to VCC = 0V is required for fail-safe operation.

Is MAX6418UK23 qualified for automotive applications, and what is its temperature rating?

Yes, MAX6418UK23 is rated for -40°C to +125°C operation and is offered in automotive-grade variants (e.g., MAX6418UK23/V+T). While not explicitly AEC-Q200 certified in this datasheet, its extended temperature range, transient immunity, and production testing align with automotive body electronics requirements - confirm qualification status with Analog Devices for specific grade compliance.

What is the maximum VCC transient duration that MAX6418UK23 can ignore without issuing a false reset?

MAX6418UK23 is immune to negative-going VCC transients ≤50µs in duration when the overdrive magnitude is 100mV below its 2.313V threshold. This immunity is characterized in the "Maximum Transient Duration vs. Reset Threshold Overdrive" graph (Figure 5) and ensures robust operation in electrically noisy environments like automotive power systems and motor-driven equipment.