Analog Devices Inc./Maxim Integrated MAX6866UK29D3L

Overview

MAX6866UK29D3L from Maxim Integrated is a nanopower microprocessor supervisory circuit in 5-pin SOT23 package, featuring ultra-low 170nA typical supply current, factory-trimmed 2.925V reset threshold (suffix "29"), 300ms minimum reset timeout (suffix "D3"), and watchdog timer with 209s typical timeout (suffix "L"). It monitors VCC, responds to manual reset (MR), and triggers reset on watchdog expiration - designed for battery-powered medical and portable electronics.

For engineers reviewing the MAX6866UK29D3L datasheet, MAX6866UK29D3L pinout, MAX6866UK29D3L application, or MAX6866UK29D3L equivalent, key selection criteria include its guaranteed reset validity down to VCC = +1.1V, immunity to short VCC transients (<40µs at 100mV overdrive), push-pull active-low reset output, and compatibility with noisy low-power systems requiring precise brownout detection and software fault recovery.

Technical Context

The MAX6866UK29D3L integrates voltage monitoring, manual reset input (MR), and watchdog timer (WDI) in a single BiCMOS IC. Its reset assertion logic combines three independent triggers: VCC falling below 2.925V ±2.5%, MR pulled low, or WDI inactivity exceeding 209s (typ). The internal reset timeout generator ensures 300ms (min) reset pulse width after any trigger condition clears.

It uses a dedicated WDI input with 150ns minimum pulse width detection and glitch rejection; the watchdog timer resets on any rising/falling edge and halts during active reset. The device guarantees valid reset output down to VCC = +1.1V and operates across -40°C to +85°C with no external components required.

Key Specifications

Pinout & Package

MAX6866UK29D3L is housed in a RoHS-compliant 5-pin SOT23-5 package (2.9mm × 1.6mm × 1.1mm), optimized for space-constrained portable designs. Pin 1 is RESET, Pin 2 is GND, Pin 3 is MR, Pin 4 is WDI, and Pin 5 is VCC - fully compatible with standard SOT23 pick-and-place equipment.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6866UK29D3L, MAX6864UK29D3L offers identical supervision performance with reduced feature set, while TPS3838K29 trades off watchdog capability and nanopower operation for TI ecosystem alignment and simplified qualification.

Availability

MAX6866UK29D3L is available at Aetrix Electronics and suitable for glucose monitors, patient monitors, industrial handheld terminals, and smart asset trackers requiring stable component supply across extended production lifecycles.

Supply support for MAX6866UK29D3L 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 delivers nanopower supervision for battery-critical systems, combining precision voltage monitoring, robust manual reset, and configurable watchdog timing in minimal-footprint packages.

FAQ

What is the exact reset threshold voltage of MAX6866UK29D3L?

The MAX6866UK29D3L has a factory-trimmed reset threshold voltage of 2.925V, with ±2.5% tolerance over temperature (-40°C to +85°C). This value is confirmed in Table 2 (Threshold Suffix Guide) of the datasheet, where suffix "29" corresponds to 2.925V nominal. The device guarantees valid reset assertion down to VCC = +1.1V, making MAX6866UK29D3L suitable for brownout detection in 3.0V and 3.3V systems approaching end-of-life battery voltage.

Does MAX6866UK29D3L support watchdog timer functionality?

Yes, MAX6866UK29D3L includes a watchdog timer with a typical timeout period of 209s (L-suffix), as specified in Table 3 (Watchdog Timeout). The WDI input detects rising/falling edges ≥150ns and clears the timer on each transition. Watchdog expiration triggers reset independently of VCC and MR conditions, and the timer remains halted while reset is asserted - a core feature confirmed in the Functional Diagram (Figure 1) and Detailed Description section.

What is the reset timeout period for MAX6866UK29D3L?

The MAX6866UK29D3L features a fixed minimum reset timeout period of 300ms, indicated by the "D3" suffix per Table 4 (Reset Timeout Periods). Typical and maximum values are 225ms and 300ms respectively. This timeout begins after VCC rises above 2.925V and MR deasserts, ensuring the microprocessor has sufficient time to stabilize before release - a timing parameter validated in Figure 2 (RESET Timing Relationship).

What package type and pin configuration does MAX6866UK29D3L use?

MAX6866UK29D3L uses a 5-pin SOT23-5 package with standard pinout: Pin 1 = RESET (active-low open-drain), Pin 2 = GND, Pin 3 = MR (active-low manual reset), Pin 4 = WDI (watchdog input), Pin 5 = VCC. This configuration is explicitly shown in the "MAX6864/MAX6865/MAX6866 Pin Description" section and the "Pin Configurations" diagram (page 15), confirming full compatibility with automated assembly processes.

Is MAX6866UK29D3L suitable for battery-powered medical devices?

Yes, MAX6866UK29D3L is specifically designed for battery-powered medical devices such as glucose monitors and patient monitors. Its 170nA typical supply current enables multi-year operation on coin cells, guaranteed reset validity to VCC = +1.1V ensures safety during deep discharge, and 209s watchdog timeout supports long-duration clinical algorithms - all features highlighted in the Applications and Features sections of the datasheet.