Analog Devices Inc./Maxim Integrated MAX6412UK29

Overview

MAX6412UK29 from Maxim Integrated is a low-power, single-voltage microprocessor reset supervisor IC with factory-trimmed 2.925V VCC reset threshold, active-low push-pull RESET output, manual reset input (MR), and capacitor-adjustable reset timeout delay. It monitors supply voltage from 1.6V to 5V, asserts reset below threshold or on MR assertion, and holds reset for programmable duration after recovery - used in battery-powered controllers and embedded systems requiring reliable power-on reset and brownout protection.

For engineers reviewing the MAX6412UK29 datasheet, MAX6412UK29 pinout, MAX6412UK29 application, or MAX6412UK29 equivalent, key selection criteria include its guaranteed reset validity down to VCC = 1V, 1.7µA typical quiescent current, SOT23-5 package compatibility, and capacitor-programmable timeout (275µs base + 2.71×10⁶ × CSRT).

Technical Context

The MAX6412UK29 implements a precision bandgap-based voltage comparator for VCC monitoring with ±1.25% threshold accuracy at +25°C and ±2.5% over –40°C to +125°C. Its internal 240nA current source charges an external capacitor on SRT to generate a ramp-based timeout period, cleared on any reset event.

It features a 20kΩ internal MR pullup resistor, supports manual reset pulse widths ≥1µs, and provides glitch rejection of 75ns on MR. The active-low push-pull RESET output drives logic-compatible loads with VOL ≤ 0.4V at ISINK = 3.2mA (VCC ≥ 4.5V) and VOH ≥ 0.8×VCC at ISOURCE = 800µA.

Key Specifications

Pinout & Package

SOT23-5 package: ultra-compact 2.9mm × 1.6mm footprint, surface-mount, lead-free (RoHS-compliant) or leaded options available.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6412UK29, MAX6316LUK29D3+ trades timeout flexibility for lower cost and simpler layout, while TPS3808G33DBVR offers lower current but requires voltage and package adaptation - making MAX6412UK29 optimal for 2.9–3.0V systems needing field-tunable reset duration.

Availability

MAX6412UK29 is available at Aetrix Electronics and suitable for battery-powered computers/controllers, embedded controllers, and critical µP monitoring applications requiring stable component supply across automotive, medical, and industrial programs.

Supply support for MAX6412UK29 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 demanding environments.

The MAX6412–MAX6420 family delivers ultra-low-power, capacitor-programmable reset supervision for space-constrained, battery-operated, and high-reliability systems where voltage margin and timeout flexibility are critical.

FAQ

What is the exact factory-trimmed reset threshold voltage for MAX6412UK29?

The MAX6412UK29 has a factory-trimmed VCC reset threshold of 2.925V, with ±1.25% typical accuracy at +25°C and ±2.5% maximum variation across –40°C to +125°C. This value is confirmed in Table 1 of the datasheet (suffix "29") and Electrical Characteristics section under VTH parameter.

Does MAX6412UK29 support manual reset functionality, and how is it implemented?

Yes, MAX6412UK29 includes a dedicated MR (manual reset) input on Pin 3. It features an internal 20kΩ pullup resistor, so connecting a normally open momentary switch from MR to ground provides full manual reset capability without external components. The device asserts RESET for the full timeout period after switch release.

What is the minimum external capacitor value required for the SRT pin of MAX6412UK29 to achieve a specific reset timeout?

The reset timeout tRP (seconds) is calculated as tRP = (2.71 × 10⁶) × CSRT + 275µs. To achieve, for example, a 200ms timeout, solve for CSRT: CSRT = (0.2 – 0.000275) / 2.71e6 ≈ 73.3nF. Ceramic capacitors with leakage <10nA are recommended; values below ~100pF yield timeouts near the 275µs base.

Can MAX6412UK29 operate reliably at VCC = 1.2V, and what is the behavior of its RESET output at that voltage?

Yes, MAX6412UK29 is guaranteed to assert and deassert RESET validly down to VCC = 1.0V. At VCC = 1.2V, RESET remains functional: VOL ≤ 0.3V (ISINK = 500µA) and VOH ≥ 0.8 × VCC = 0.96V (ISOURCE = 200µA), ensuring compatible logic levels with ultra-low-voltage µPs.

Is MAX6412UK29 pin-compatible with other members of the MAX6412–MAX6420 family, such as MAX6418UK29?

Yes, MAX6412UK29 shares the identical SOT23-5 package and pinout (RESET, GND, MR, SRT, VCC) with all MAX6412–MAX6420 variants, including MAX6418UK29. However, MAX6418UK29 adds an adjustable RESET IN input (replacing MR), so direct substitution requires circuit validation - MAX6412UK29 retains MR and fixed-threshold-only operation.