Analog Devices Inc./Maxim Integrated MAX6869UK225D3S

Overview

MAX6869UK225D3S from Maxim Integrated is a nanopower microprocessor supervisory circuit in 5-pin SOT23 package, combining voltage monitoring (2.235V reset threshold), manual reset input (MR), and watchdog timer (209s typical timeout). It asserts an active-low push-pull RESET output for ≥225ms after VCC rise or MR deassertion, and guarantees valid reset down to VCC = +1.1V. Designed for ultra-low-power battery-operated medical and portable electronics.

For engineers reviewing the MAX6869UK225D3S datasheet, MAX6869UK225D3S pinout, MAX6869UK225D3S application, or MAX6869UK225D3S equivalent, key selection criteria include its 170nA typical supply current, factory-trimmed 2.235V threshold, 225ms minimum reset timeout, 209s watchdog period, and SOT23-5 footprint compatibility with TPS383x series.

Technical Context

The MAX6869UK225D3S integrates a precision bandgap-based voltage monitor, a monostable reset timeout generator with fixed 225ms minimum delay (D3 option), and a watchdog timer that clears on any WDI edge and expires after 209s (L-suffix) if inactive. Its internal 10kΩ MR pullup enables direct switch interfacing without external components.

It operates across VCC = 1.2V to 5.5V and guarantees RESET assertion validity down to VCC = +1.1V, with immunity to VCC transients ≤40µs at 100mV overdrive. The push-pull active-low RESET output drives logic directly without external pullup, supporting CMOS-level interfacing.

Key Specifications

Pinout & Package

MAX6869UK225D3S uses a 5-pin SOT23-5 package (2.9mm × 1.6mm × 1.1mm), optimized for space-constrained portable designs. Pin 1 is WDI, Pin 2 is GND, Pin 3 is MR, Pin 4 is RESET, and Pin 5 is VCC - matching the MAX6867–MAX6869 family pinout.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6867UK225D3S and TPS3836K33DBVR, MAX6869UK225D3S uniquely delivers both ultra-low 170nA ICC and integrated 209s watchdog in the same SOT23-5 footprint-enabling extended battery life *and* firmware fault recovery in single-chip form.

Availability

MAX6869UK225D3S is available at Aetrix Electronics and suitable for glucose monitors, patient monitors, wireless sensor nodes, and industrial handheld scanners requiring stable component supply across extended production lifecycles.

Supply support for MAX6869UK225D3S 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 precision analog, mixed-signal, and power management ICs for industrial, medical, and communications applications.

The MAX68xx supervisory family was designed specifically for ultra-low-power, battery-critical applications such as portable medical devices and IoT endpoints-emphasizing nanoscale ICC, guaranteed reset validity at low VCC, and integrated watchdog safety.

FAQ

What is the exact reset threshold voltage of MAX6869UK225D3S?

The MAX6869UK225D3S has a factory-trimmed reset threshold of 2.235V, 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 "225" corresponds to 2.235V nominal. The device guarantees valid reset assertion down to VCC = +1.1V, making it suitable for deep brownout conditions.

Does MAX6869UK225D3S include a watchdog timer, and what is its timeout?

Yes, MAX6869UK225D3S includes a watchdog timer with a typical timeout of 209s (L-suffix), as specified in Table 3 (Watchdog Timeout). The timer clears on any rising or falling edge at the WDI pin and expires only if WDI remains static beyond this period. It is fully integrated-no external RC components are required.

What is the reset timeout duration for MAX6869UK225D3S, and is it adjustable?

The MAX6869UK225D3S has a fixed minimum reset timeout of 225ms (D3 option), per Table 4 (Reset Timeout Periods). This duration is factory-set and non-adjustable. Unlike MAX6861–MAX6863 variants, MAX6869UK225D3S does not feature a CT pin for dynamic timeout selection.

What package type and pin configuration does MAX6869UK225D3S use?

MAX6869UK225D3S uses a 5-pin SOT23-5 package with standard pinout: Pin 1 = WDI, Pin 2 = GND, Pin 3 = MR, Pin 4 = RESET (active-low push-pull), Pin 5 = VCC. This matches the MAX6867–MAX6869 family layout shown in the Pin Configurations section (page 16) and is mechanically and electrically compatible with TPS383x series.

How does the manual reset (MR) function work on MAX6869UK225D3S?

The MR input on MAX6869UK225D3S is active-low with an internal 10kΩ pullup to VCC. Driving MR low initiates a reset that persists for the full 225ms timeout period after MR returns high. Glitch rejection is 200ns, and minimum pulse width is 1µs. No external components are needed-just connect a momentary switch from MR to GND for user-initiated reset.