Analog Devices Inc./Maxim Integrated MAX6865UK30D3S+T

Overview

The MAX6865UK30D3S+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in a 5-pin SOT23 package, combining voltage monitoring (3.000V factory-trimmed reset threshold), manual reset input (MR), and watchdog timer (209s typical timeout) with ultra-low 170nA typical supply current. It asserts an active-high push-pull RESET signal during VCC brownout, MR assertion, or watchdog timeout, and guarantees valid reset operation down to VCC = +1.1V - ideal for battery-powered glucose monitors and portable medical devices.

For engineers reviewing the MAX6865UK30D3S+T datasheet, MAX6865UK30D3S+T pinout, MAX6865UK30D3S+T application, or MAX6865UK30D3S+T equivalent, key selection criteria include its 3.000V ±2.5% reset threshold, 150ms minimum reset timeout (D3), S-suffix 209s watchdog period, active-high push-pull output, and guaranteed operation at VCC ≥ 1.1V in -40°C to +85°C industrial environments.

Technical Context

This device implements a precision bandgap-based voltage monitor with 2.5% hysteresis, a digital watchdog timer cleared by WDI edge transitions (≥150ns pulse width), and a fixed 150ms reset timeout after VCC recovery or MR deassertion. Its internal 10kΩ MR pullup and noise-immune design ensure reliable reset assertion even under 40µs VCC transients at 100mV overdrive.

The MAX6865UK30D3S+T uses BiCMOS process technology (2848 transistors) to achieve 170nA typical ICC at 2.5V/25°C while maintaining push-pull RESET output drive capability: VOH ≥ 0.8×VCC (ISOURCE = 500µA) and VOL ≤ 0.3V (ISINK = 1.2mA at VCC ≥ 2.38V).

Key Specifications

Pinout & Package

Package: 5-pin SOT23-5 (lead-free, +T suffix), 2.9mm × 1.6mm footprint, 1.1mm height - compatible with high-density portable PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6865UK30D3S+T, the MAX6864UK30D3S+T requires additional interface components for active-high reset, while the TPS3836K33DBVR trades 26× higher supply current for lower cost and simpler qualification - making MAX6865UK30D3S+T optimal for battery-critical, safety-relevant medical designs requiring integrated watchdog supervision.

Availability

MAX6865UK30D3S+T is available at Aetrix Electronics and suitable for glucose monitors, portable ECG devices, and wireless patient alarms requiring stable component supply with guaranteed long-term availability and lead-free compliance.

Supply support for MAX6865UK30D3S+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 MAX6865UK30D3S+T belongs to the MAX68xx nanopower supervisory family, designed specifically for battery-powered medical and portable electronics where ultra-low ICC, guaranteed low-VCC reset validity, and integrated watchdog supervision are mandatory.

FAQ

What is the exact reset threshold voltage of the MAX6865UK30D3S+T?

The MAX6865UK30D3S+T has a factory-trimmed reset threshold of 3.000V with ±2.5% tolerance over -40°C to +85°C. This value is confirmed in Table 2 (Threshold Suffix Guide) of the datasheet, where suffix "30" corresponds to 3.000V nominal. The device guarantees valid reset assertion down to VCC = +1.1V, making it suitable for deep brownout detection in low-voltage systems.

Does the MAX6865UK30D3S+T support active-high reset output?

Yes, the MAX6865UK30D3S+T provides an active-high push-pull RESET output, as confirmed in the Pin Description section (page 8) and Selector Guide (page 16). Unlike open-drain or active-low variants, this eliminates the need for external pullup resistors and directly interfaces with µP reset inputs expecting high-active assertion - a key differentiator from MAX6864/MAX6866 variants.

What is the watchdog timeout period for the MAX6865UK30D3S+T?

The MAX6865UK30D3S+T features a watchdog timeout period of 209s typical (minimum 95s, maximum 487s), indicated by the "S" suffix in the part number. This is verified in Table 3 (Watchdog Timeout) and applies to the MAX6864–MAX6869 series. The timer resets on any WDI edge (rising or falling) and triggers reset if no transition occurs within the timeout window.

How does the reset timeout period work on the MAX6865UK30D3S+T?

The MAX6865UK30D3S+T uses the D3 reset timeout option, providing a minimum 150ms reset assertion period after VCC rises above 3.000V or MR is deasserted. This is fixed (not pin-selectable) and ensures sufficient time for µP power stabilization and internal initialization before release - critical for reliable boot in medical-grade devices.

Is the MAX6865UK30D3S+T compatible with 1.8V supply systems?

Yes, the MAX6865UK30D3S+T operates across VCC = 1.2V to 5.5V and guarantees valid reset function down to VCC = +1.1V. Its 3.000V threshold is appropriate for monitoring 3.3V rails, but the device itself can be powered from 1.8V (with reduced sink/source drive strength per Electrical Characteristics table), enabling use in mixed-voltage systems where supervisor and µP operate at different rails.