Analog Devices Inc./Maxim Integrated MAX6867UK17D3S

Overview

The MAX6867UK17D3S from Maxim Integrated is a nanopower microprocessor supervisory circuit in a 5-pin SOT23 package, combining voltage monitoring, manual reset input (MR), and watchdog timer (WDI) functions. It asserts an active-low push-pull RESET when VCC drops below 1.665V (±2.5%), MR is pulled low, or WDI fails to toggle within 3.3s (typ). Designed for ultra-low-power systems, it draws only 170nA (typ) at 2.5V and guarantees valid reset down to VCC = 1.1V.

For engineers reviewing the MAX6867UK17D3S datasheet, MAX6867UK17D3S pinout, MAX6867UK17D3S application, or MAX6867UK17D3S equivalent, key selection criteria include its 1.665V factory-trimmed reset threshold, 150ms minimum reset timeout, 3.3s watchdog period, push-pull active-low reset output, and immunity to short VCC transients - all critical for battery-powered medical and portable electronics.

Technical Context

The MAX6867UK17D3S implements a dual-monitoring architecture: a precision bandgap-based voltage detector with 2.5% threshold tolerance and a digital watchdog timer that clears on any WDI edge (rising or falling) and expires if no transition occurs within 3.3s (typ). Its internal 10kΩ MR pullup and glitch rejection (200ns) enable robust manual reset without external components.

Reset assertion is latched and held for a guaranteed minimum 150ms after VCC rises above threshold and MR deasserts; the watchdog timeout is temperature-stable (±15% over –40°C to +85°C), and the device remains functional down to VCC = 1.1V - enabling reliable supervision during deep brownout conditions.

Key Specifications

Pinout & Package

Package: 5-pin SOT23-5 (2.9mm × 1.6mm × 1.1mm), lead-free, RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6867UK17D3S, MAX6864UK16D3S offers lower threshold for marginal supplies but same watchdog performance, while TPS3836K33DBVR trades nanopower efficiency and watchdog capability for cost and simplicity in non-critical applications.

Availability

MAX6867UK17D3S is available at Aetrix Electronics and suitable for glucose monitors, patient monitors, smart wearables, industrial handheld terminals, and portable medical diagnostics requiring stable component supply across extended product lifecycles.

Supply support for MAX6867UK17D3S 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 MAX68xx family was designed specifically for ultra-low-power microprocessor supervision in battery-critical portable medical and consumer electronics, emphasizing nanoscale current consumption and robust fault detection.

FAQ

What is the exact reset threshold voltage of the MAX6867UK17D3S?

The MAX6867UK17D3S has a factory-trimmed reset threshold voltage of 1.665V, with a tolerance of ±2.5% over the full temperature range (–40°C to +85°C). This value is confirmed in Table 2 (Threshold Suffix Guide) of the datasheet, where suffix "17" corresponds to 1.665V nominal. The device guarantees valid reset assertion down to VCC = 1.1V, making it suitable for brownout detection in 1.8V systems with tight margins.

Does the MAX6867UK17D3S include a watchdog timer, and what is its timeout period?

Yes, the MAX6867UK17D3S includes a watchdog timer with a typical timeout period of 3.3 seconds, denoted by the "S" suffix in the part number. The watchdog monitors the WDI pin and triggers a reset if no rising or falling edge occurs within this period. The timeout exhibits ±15% variation over temperature, and the timer resets on any WDI transition, MR assertion, or RESET assertion - ensuring responsive fault recovery in embedded firmware.

What type of reset output does the MAX6867UK17D3S provide, and how is it configured?

The MAX6867UK17D3S provides a push-pull active-low RESET output (pin 4), as confirmed by its pin configuration diagram and Selector Guide. This output drives actively low during fault conditions and actively high (to VCC) when deasserted - eliminating the need for an external pullup resistor. It can sink ≥50µA at VCC ≥1.1V and source ≥200µA at VCC ≥1.71V, ensuring compatibility with standard CMOS reset inputs.

What is the minimum reset timeout period for the MAX6867UK17D3S, and how is it set?

The MAX6867UK17D3S has a fixed minimum reset timeout period of 150ms, indicated by the "D3" suffix in the part number (per Table 4: Reset Timeout Periods). Unlike the MAX6861–MAX6863 series, it does not feature a pin-selectable timeout - the 150ms duration is factory-programmed and guaranteed over temperature. This interval ensures sufficient time for µP power stabilization and internal register initialization before release.

Is the MAX6867UK17D3S compatible with 1.8V supply rails, and how does it handle brownout conditions?

Yes, the MAX6867UK17D3S is fully compatible with 1.8V supply rails: its 1.665V reset threshold provides 135mV of headroom below nominal VCC, and it guarantees valid RESET assertion down to VCC = 1.1V. During brownout, the device asserts RESET before the µP enters undefined states, holds it for ≥150ms after VCC recovers above threshold, and rejects transients ≤40µs - ensuring robust operation in noisy, battery-depleted environments.