Analog Devices Inc./Maxim Integrated MAX6864UK46D3S+T

Overview

The MAX6864UK46D3S+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in a 5-pin SOT23 package, featuring ultra-low 170nA typical supply current, factory-trimmed 4.625V reset threshold (±2.5%), 300ms minimum reset timeout, and integrated watchdog timer with 3.3s typical timeout. It monitors VCC, responds to manual reset (MR), and triggers reset on watchdog timeout - designed for battery-critical portable medical and consumer electronics.

For engineers reviewing the MAX6864UK46D3S+T datasheet, MAX6864UK46D3S+T pinout, MAX6864UK46D3S+T application, or MAX6864UK46D3S+T equivalent, this page delivers verified functional identity, validated pin roles, confirmed timing parameters, and real-world substitution guidance - all aligned to the official MAX6864 family specification.

Technical Context

The MAX6864UK46D3S+T implements a dual-trigger reset architecture: voltage monitoring asserts reset when VCC falls below 4.625V (with 0.5% hysteresis), while the watchdog timer expires if WDI remains static beyond 3.3s (typ). Reset output remains asserted for ≥300ms after VCC recovery, MR deassertion, or watchdog expiration.

It operates across -40°C to +85°C with guaranteed reset validity down to VCC = 1.1V, features internal 10kΩ MR pullup, and supports push-pull active-low RESET output. The device requires no external components and is immune to VCC transients ≤40µs at 100mV overdrive.

Key Specifications

Pinout & Package

Package: 5-pin SOT23-5, lead-free, surface-mount, 2.9mm × 1.6mm footprint.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6864UK46D3S+T, MAX6865UK46D3S+T changes reset polarity but retains identical timing and watchdog behavior, while TPS3836K33DBVR omits watchdog entirely and targets lower-voltage rails - making MAX6864UK46D3S+T uniquely suited for 4.6V+ systems requiring both voltage and code-execution supervision.

Availability

MAX6864UK46D3S+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 MAX6864UK46D3S+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 communications applications.

The MAX6864UK46D3S+T belongs to the MAX68xx nanopower supervisory family, engineered specifically for ultra-low-current, single-chip reset and watchdog supervision in space- and energy-constrained portable systems.

FAQ

What is the exact reset threshold voltage of the MAX6864UK46D3S+T?

The MAX6864UK46D3S+T has a factory-trimmed reset threshold of 4.625V, with guaranteed tolerance of ±2.5% over -40°C to +85°C. This value is confirmed in Table 2 (Threshold Suffix Guide) of the official datasheet, where suffix '46' corresponds to 4.625V nominal. The device asserts reset when VCC falls below this threshold and holds reset for ≥300ms after VCC rises above it.

Does the MAX6864UK46D3S+T include a watchdog timer, and what is its timeout?

Yes, the MAX6864UK46D3S+T includes an integrated watchdog timer with a typical timeout of 3.3s, indicated by the 'S' suffix in the part number. The timer expires if the WDI pin remains static (no rising or falling edge) beyond this period, triggering a reset pulse for the configured 300ms timeout. The timer clears on any WDI edge, MR assertion, or active reset condition.

What is the function of Pin 4 (WDI) on the MAX6864UK46D3S+T?

Pin 4 (WDI) is the watchdog input terminal of the MAX6864UK46D3S+T. It monitors µP software activity: a rising or falling edge clears the internal watchdog timer, while absence of edges longer than 3.3s (typ) causes timeout and reset assertion. WDI accepts CMOS logic levels (VIH = 0.7×VCC, VIL = 0.3×VCC) and detects pulses as short as 150ns - enabling tight integration with GPIO or dedicated watchdog pins.

Can the MAX6864UK46D3S+T operate reliably at low supply voltages?

Yes, the MAX6864UK46D3S+T guarantees valid reset assertion down to VCC = 1.1V, as specified in the Electrical Characteristics table. Its 170nA typical supply current allows operation across the full 1.2V–5.5V range, and the push-pull RESET output remains functional even during deep brownout conditions - critical for fail-safe behavior in battery-powered systems approaching end-of-life voltage.

Is the MAX6864UK46D3S+T pin-compatible with other devices in the MAX68xx family?

The MAX6864UK46D3S+T uses the standard 5-pin SOT23-5 package and shares identical pinout (RESET, GND, MR, WDI, VCC) with MAX6865/MAX6866 variants. However, it is not pin-compatible with MAX6861–MAX6863 (which use CT instead of WDI) or MAX6854–MAX6856 (which lack WDI). Always verify pin function alignment using the MAX6864-specific pin description before substitution.