Analog Devices Inc./Maxim Integrated MAX6864UK29D3S+T

Overview

MAX6864UK29D3S+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in 5-pin SOT23 package, featuring ultra-low 170nA typical supply current, factory-trimmed 2.925V reset threshold (suffix "29"), 300ms minimum reset timeout (suffix "D3"), and 3.3s typical watchdog timeout (suffix "S"). It monitors VCC, responds to manual reset (MR), and triggers reset on watchdog timeout - designed for battery-powered medical and portable electronics requiring guaranteed reset validity down to VCC = +1.1V.

For engineers reviewing the MAX6864UK29D3S+T datasheet, MAX6864UK29D3S+T pinout, MAX6864UK29D3S+T application, or MAX6864UK29D3S+T equivalent, this page delivers verified functional specifications, validated pin roles, confirmed timing behavior under temperature and voltage variation, and real-world substitution guidance for low-power µP supervision in glucose monitors, patient monitors, and handheld devices.

Technical Context

The MAX6864UK29D3S+T integrates three core functions: precision voltage monitoring with ±2.5% threshold accuracy over -40°C to +85°C, a manual reset input with 250ns MR-to-reset delay and internal 10kΩ pullup, and a watchdog timer that clears on any WDI edge and expires after 3.3s (typ) if inactive. Its reset assertion logic combines VCC undervoltage, MR assertion, and WDI timeout - all triggering a single push-pull active-low RESET output.

Reset deassertion follows a fixed 300ms (min) timeout after VCC rises above 2.925V *and* MR is deasserted *and* WDI activity resumes. The device guarantees valid RESET output down to VCC = +1.1V and exhibits immunity to VCC transients ≤40µs at 100mV overdrive - critical for noisy battery-supplied systems where brownout resilience and glitch rejection are mandatory.

Key Specifications

Pinout & Package

Package: 5-pin SOT23-5, lead-free (RoHS-compliant), footprint compatible with industry-standard 5-pin SOT23 layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3836K33DBVR and MAX6369KA29D3+T, the MAX6864UK29D3S+T uniquely delivers integrated watchdog + manual reset + nanopower operation in one 5-pin SOT23, enabling robust fault recovery in battery-critical medical and portable systems without design trade-offs.

Availability

MAX6864UK29D3S+T is available at Aetrix Electronics and suitable for glucose monitors, patient monitors, and MP3 players requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MAX6864UK29D3S+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) is a semiconductor company specializing in high-performance analog, mixed-signal, and power-management ICs for industrial, medical, and consumer applications.

The MAX6864UK29D3S+T belongs to Maxim's nanopower µP supervisory family, engineered specifically for ultra-low-power, safety-aware embedded systems where extended battery life and deterministic reset behavior are non-negotiable.

FAQ

What is the exact reset threshold voltage of the MAX6864UK29D3S+T?

The MAX6864UK29D3S+T has a factory-trimmed reset threshold voltage of 2.925V, with ±2.5% tolerance over the full operating temperature range (-40°C to +85°C). This value is defined by the "29" suffix in the part number and is confirmed in Table 2 (Threshold Suffix Guide) of the official datasheet. The MAX6864UK29D3S+T maintains this accuracy without external calibration.

Does the MAX6864UK29D3S+T include a watchdog timer, and what is its timeout period?

Yes, the MAX6864UK29D3S+T includes a watchdog timer with a typical timeout period of 3.3s, indicated by the "S" suffix in the part number. The timer clears on any rising or falling edge at the WDI pin and expires only if WDI remains static longer than this period. The MAX6864UK29D3S+T does not support user-programmable timeout values - it is fixed at 3.3s (typ) per datasheet Table 3.

What is the reset timeout period of the MAX6864UK29D3S+T, and how is it set?

The MAX6864UK29D3S+T has a fixed minimum reset timeout period of 300ms, denoted by the "D3" suffix. This duration begins after VCC rises above 2.925V *and* MR is deasserted *and* WDI activity resumes, ensuring the microprocessor completes power-rail stabilization and internal initialization before reset release. The MAX6864UK29D3S+T does not require external components to configure this timing.

Is the MAX6864UK29D3S+T pin-compatible with other supervisory ICs?

The MAX6864UK29D3S+T uses a standard 5-pin SOT23-5 package with pin 1 = RESET, pin 2 = GND, pin 3 = MR, pin 4 = WDI, pin 5 = VCC. It is not pin-compatible with TPS3836/TPS3837/TPS3838, which lack WDI and have different pinouts. However, the MAX6864UK29D3S+T shares the same footprint and thermal profile as other MAX68xx devices in the family, enabling drop-in replacement within that series.

What is the supply current of the MAX6864UK29D3S+T, and how does it vary with voltage?

The MAX6864UK29D3S+T draws 170nA typical supply current at VCC = 1.8V, 190nA at 3.3V, and 210nA at 5.0V - all measured with reset deasserted and no load. This ultra-low ICC is confirmed in the Electrical Characteristics table and enables multi-year operation on coin-cell batteries. The MAX6864UK29D3S+T maintains sub-µA consumption across its full 1.2V–5.5V operating range.