Analog Devices Inc./Maxim Integrated MAX6864UK16D3S+T

Overview

The MAX6864UK16D3S+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in a 5-pin SOT23 package, combining voltage monitoring (1.575V reset threshold), manual reset input (MR), and watchdog timer (3.3s timeout) with ultra-low 170nA typical supply current. It asserts an active-low push-pull RESET output during VCC brownout, MR assertion, or watchdog timeout, ensuring reliable boot-up and fault recovery in battery-powered systems.

For engineers reviewing the MAX6864UK16D3S+T datasheet, MAX6864UK16D3S+T pinout, MAX6864UK16D3S+T application, or MAX6864UK16D3S+T equivalent, key selection criteria include its 1.575V factory-trimmed reset threshold, 300ms minimum reset timeout (D3), 3.3s watchdog period (S suffix), push-pull active-low RESET output, and guaranteed reset validity down to VCC = +1.1V.

Technical Context

The MAX6864UK16D3S+T integrates a precision voltage monitor with ±2.5% threshold accuracy, a glitch-immune manual reset input with 250ns MR-to-reset delay and 1µs minimum pulse width, and a watchdog timer that clears on any WDI edge and expires if WDI remains static beyond 3.3s (typ). Its internal 10kΩ MR pullup eliminates external components.

This device operates across VCC = 1.2V to 5.5V and guarantees functional reset assertion down to VCC = 1.1V. The watchdog timeout exhibits <±20% variation over –40°C to +85°C, and the reset timeout is fixed at 150–300ms (min/typ/max per D3 option), independent of temperature.

Key Specifications

Pinout & Package

Package: 5-pin SOT23-5, lead-free, surface-mount, 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 supervisory applications.

Compared with TPS3836K33DBVR and MAX6361KA29D3+T, the MAX6864UK16D3S+T uniquely delivers integrated watchdog supervision at nanopower levels, enabling single-chip safety-critical reset management in space-constrained, battery-operated medical and portable electronics.

Availability

MAX6864UK16D3S+T is available at Aetrix Electronics and suitable for portable medical devices, battery-powered instrumentation, and low-power consumer electronics requiring stable component supply, long-term lifecycle support, and guaranteed lead-free compliance.

Supply support for MAX6864UK16D3S+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 power management, sensing, and interface applications in industrial, medical, and communications markets.

The MAX6864UK16D3S+T belongs to Maxim's nanopower µP supervisory family, engineered specifically for ultra-low-power, safety-critical reset supervision in battery-constrained portable systems with stringent reliability requirements.

FAQ

What is the exact reset threshold voltage of the MAX6864UK16D3S+T?

The MAX6864UK16D3S+T has a factory-trimmed reset threshold of +1.575V, with guaranteed tolerance of ±2.5% over –40°C to +85°C. This value is encoded in the "16" suffix per Maxim's Threshold Suffix Guide (Table 2), making it suitable for monitoring 1.8V supply rails where early brownout detection is critical. The MAX6864UK16D3S+T maintains this accuracy without external calibration.

Does the MAX6864UK16D3S+T require external components for basic operation?

No, the MAX6864UK16D3S+T operates autonomously with zero external components: it features an internal 10kΩ pullup on MR, a precision bandgap reference for voltage monitoring, and a self-contained watchdog oscillator. Only a 0.1µF ceramic capacitor from VCC to GND is recommended for noise suppression - no resistors, capacitors, or additional ICs are needed for reset generation or watchdog functionality.

How does the watchdog timer in the MAX6864UK16D3S+T respond to software stalls?

The MAX6864UK16D3S+T watchdog timer expires if the WDI input remains static (high or low) for longer than 3.3s (typical), triggering a full reset sequence. It clears on every rising or falling edge of WDI, so software must toggle WDI at least once per timeout period. Unlike windowed watchdogs, it imposes no minimum toggle frequency - ideal for interrupt-driven or low-duty-cycle firmware.

What is the function of Pin 1 (RESET) on the MAX6864UK16D3S+T?

Pin 1 of the MAX6864UK16D3S+T is the active-low push-pull RESET output. It drives strongly low during VCC brownout, MR assertion, or watchdog timeout, and returns high-impedance (not actively driven high) when deasserted. This eliminates the need for an external pullup resistor and ensures clean, fast transitions into the µP's reset input, even under varying load conditions.

Can the MAX6864UK16D3S+T operate reliably at VCC = 1.2V?

Yes, the MAX6864UK16D3S+T is fully specified to operate at VCC = 1.2V, with guaranteed reset assertion down to VCC = +1.1V. At 1.2V, its supply current remains ultra-low (≤370nA typ), and all timing parameters - including 300ms reset timeout and 3.3s watchdog period - remain valid. This enables robust operation in deeply scaled battery systems where voltage sags below 1.5V are common.