Analog Devices Inc./Maxim Integrated MAX6424UK23

Overview

MAX6424UK23 from Maxim Integrated is a low-power microprocessor supervisor IC that monitors VCC supply voltage and asserts an active-low push-pull reset signal when voltage falls below 2.313V (typical threshold). It features capacitor-adjustable reset timeout (275µs to >5ms), guaranteed reset validity down to VCC = 1V, and operates across –40°C to +125°C in a 5-pin SOT23-5 package. It is used in battery-powered controllers and automotive ECUs for reliable power-on reset and brownout protection.

For engineers reviewing the MAX6424UK23 datasheet, MAX6424UK23 pinout, MAX6424UK23 application, or MAX6424UK23 equivalent, key selection considerations include its 2.313V reset threshold accuracy (±2.5% over temperature), 1.6µA typical quiescent current, push-pull output drive capability, SRT pin-based timeout programming, and compatibility with industrial-grade voltage monitoring requirements.

Technical Context

The MAX6424UK23 implements a precision voltage detector with laser-trimmed internal resistors to set its 2.313V nominal reset threshold, with ±2.5% tolerance over –40°C to +125°C. Its reset assertion is triggered by VCC falling below this threshold, and deassertion occurs after a user-defined timeout period determined by an external capacitor on the SRT pin.

Internally, a 240nA current source charges the SRT capacitor to a 0.65V ramp threshold; reset remains asserted until the capacitor voltage reaches this level. The push-pull RESET output drives low to ≤0.4V at 3.2mA sink and high to ≥0.8×VCC at 800µA source, ensuring robust interface with µP reset inputs without external pull-up components.

Key Specifications

Pinout & Package

MAX6424UK23 is housed in a RoHS-compliant 5-pin SOT23-5 package (package code U5+2), with 0.95mm pitch, 2.9mm × 1.6mm footprint, and thermal pad omitted. Pin 3 is internally unconnected (N.C.) and must be left floating or tied to GND per layout best practice.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6424UK23, NCP302LSN23T1G offers slightly lower ICC but sacrifices timeout adjustability, while TLV809E23DBZR achieves sub-µA quiescent current in a smaller 3-pin package but locks timeout at 140ms - making MAX6424UK23 the only option supporting precise, application-tuned reset delays from 275µs upward.

Availability

MAX6424UK23 is available at Aetrix Electronics and suitable for automotive body control modules, portable medical monitors, industrial PLC subsystems, smart energy meters, and battery-powered embedded controllers requiring stable component supply across extended temperature and long lifecycle programs.

Supply support for MAX6424UK23 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, automotive, and computing applications.

The MAX6424UK23 belongs to the MAX6340/MAX6421–MAX6426 family of low-power µP supervisors, engineered specifically for reliable voltage monitoring and reset generation in space-constrained, battery-sensitive, and high-reliability systems.

FAQ

What is the exact reset threshold voltage of MAX6424UK23?

The MAX6424UK23 has a nominal reset threshold of 2.313V, with guaranteed minimum of 2.255V and maximum of 2.371V at +25°C, and ±2.5% variation over –40°C to +125°C. This value is laser-trimmed at wafer test and specified in Table 1 of the datasheet under suffix "23". The threshold is referenced to VCC and remains stable across its 1.0V–5.5V operating range.

How do I calculate the reset timeout capacitor for MAX6424UK23?

Use the formula CSRT = (tRP − 275µs) / 2.73×10⁶, where tRP is the desired timeout in seconds and CSRT is in farads. For example, a 4.375ms timeout requires CSRT = (0.004375 − 0.000275) / 2.73×10⁶ = 1500pF. MAX6424UK23 requires low-leakage ceramic capacitors (<10nA); X7R or C0G dielectrics are recommended for stability.

Can MAX6424UK23 operate with a 1.2V supply rail?

Yes, MAX6424UK23 functions with VCC as low as 1.0V and guarantees RESET assertion validity down to that level. At 1.2V, its reset threshold remains 2.313V - meaning it will assert RESET immediately upon power-up since VCC < VTH, and hold RESET until VCC rises above 2.313V and the timeout expires. This makes it unsuitable for supervising 1.2V rails directly but ideal for higher rails like 2.5V, 3.3V, or 5V.

Is the SRT pin of MAX6424UK23 compatible with standard ceramic capacitors?

Yes, the SRT pin of MAX6424UK23 is designed for standard low-leakage ceramic capacitors (X7R, C0G/NP0), with recommended values from 0pF to 1500pF. Leakage must be <10nA; avoid high-K dielectrics like Y5V or Z5U. Layout best practice requires short, isolated SRT traces away from digital signals and high-voltage nodes to prevent timing errors caused by stray capacitance or leakage currents.

Does MAX6424UK23 require an external pull-up resistor on the RESET pin?

No, MAX6424UK23 features an active-low push-pull RESET output and does not require an external pull-up resistor. It actively drives high to ≥0.8×VCC (up to 800µA source) and low to ≤0.4V (up to 3.2mA sink), providing full logic-level definition without external components - unlike open-drain variants such as MAX6425UK23 which do require pull-ups.