Analog Devices Inc./Maxim Integrated MAX6854UK29D4+T

Overview

The MAX6854UK29D4+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in a 5-pin SOT23 package, providing voltage monitoring, manual reset input (MR), and fixed 1200ms minimum reset timeout. It asserts an active-low open-drain RESET output when VCC drops below its factory-trimmed 2.925V threshold (±2.5%), during MR assertion, or after power-up/brownout - ensuring reliable µP initialization in ultra-low-power systems such as glucose monitors and portable medical devices.

For engineers reviewing the MAX6854UK29D4+T datasheet, MAX6854UK29D4+T pinout, MAX6854UK29D4+T application, or MAX6854UK29D4+T equivalent, key selection criteria include its 170nA typical supply current, guaranteed RESET validity down to VCC = +1.1V, immunity to short VCC transients (<40µs at 100mV overdrive), and compatibility with 1.2V–5.5V supply rails.

Technical Context

This device implements a precision bandgap-based voltage monitor with 2.5% threshold tolerance and hysteresis of 0.5% VTH, coupled with a digital timeout counter that guarantees ≥1200ms reset assertion after VCC recovery or MR deassertion. Its MR input features 10kΩ internal pullup, 1µs minimum pulse width support, and 200ns glitch rejection - enabling robust manual reset without external components.

The open-drain RESET output requires an external pullup and sinks up to 1.2mA at VCC ≥ 2.38V (VOL ≤ 0.3V), while leakage remains ≤25nA when deasserted. No watchdog timer or CT pin functionality is present - confirming MAX6854UK29D4+T as a dedicated voltage-monitoring + manual-reset variant within the MAX6854 family.

Key Specifications

Pinout & Package

Package: 5-pin SOT23-5 (lead-free, RoHS-compliant), 2.9mm × 1.6mm footprint, 1.1mm height - optimized for space-constrained portable PCBs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3836K33DBVR and MAX6361KA29D3+T, the MAX6854UK29D4+T delivers 10× lower supply current and guaranteed reset validity down to 1.1V - making it uniquely suitable for decade-life, ultra-low-VCC medical wearables where reliability under brownout is non-negotiable.

Availability

MAX6854UK29D4+T is available at Aetrix Electronics and suitable for glucose monitors, portable ECG devices, and wireless pulse oximeters requiring stable component supply across extended production lifecycles and stringent medical-grade traceability.

Supply support for MAX6854UK29D4+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 industrial, medical, and communications applications - emphasizing ultra-low-power, high-reliability performance.

The MAX6854 family targets battery-critical portable medical electronics, delivering nanopower supervision with factory-trimmed thresholds and guaranteed timing - solving brownout resilience in space- and energy-constrained systems.

FAQ

What is the exact reset threshold voltage of the MAX6854UK29D4+T?

The MAX6854UK29D4+T has a factory-trimmed reset threshold voltage of 2.925V, with ±2.5% tolerance over temperature (−40°C to +85°C). This value is confirmed in Table 2 (Threshold Suffix Guide) of the datasheet, where suffix "29" corresponds to 2.925V nominal. The device guarantees valid reset assertion down to VCC = +1.1V, independent of threshold accuracy.

Does the MAX6854UK29D4+T include a watchdog timer function?

No, the MAX6854UK29D4+T does not include a watchdog timer. It belongs to the MAX6854 base variant (per Selector Guide), which provides only voltage monitoring and manual reset (MR) functionality. Watchdog capability is exclusive to MAX6864–MAX6869 variants - confirmed by absence of WDI pin and omission from MAX6854's pin description and functional diagram.

What type of RESET output does the MAX6854UK29D4+T provide?

The MAX6854UK29D4+T provides an active-low open-drain RESET output (Pin 1), requiring an external pullup resistor. This is verified in the MAX6854/MAX6856 pin description table and Selector Guide, where MAX6854 is marked with "√" under "OPEN-DRAIN ACTIVE LOW". Push-pull variants are assigned different part numbers (e.g., MAX6855 for active-high push-pull).

What is the minimum reset timeout period for the MAX6854UK29D4+T?

The MAX6854UK29D4+T has a minimum reset timeout period of 1200ms, indicated by suffix "D4" in its part number (Table 4: Reset Timeout Periods). This is a fixed, factory-programmed delay - not pin-selectable - and ensures the reset signal remains asserted for ≥1200ms after VCC exceeds 2.925V or MR is released.

Is the MR input of the MAX6854UK29D4+T internally pulled up?

Yes, the MR input (Pin 3) of the MAX6854UK29D4+T includes a 10kΩ internal pullup resistor to VCC, as explicitly stated in the MAX6854/MAX6856 Pin Description. This eliminates the need for an external pullup and allows direct connection of a momentary switch from MR to GND for manual reset - with no debounce circuitry required.