Analog Devices Inc./Maxim Integrated MAX6861UK16

Overview

MAX6861UK16 from Maxim Integrated is a nanopower microprocessor supervisory circuit in 5-pin SOT23 package, featuring ultra-low 170nA typical supply current, factory-trimmed 1.575V reset threshold, pin-selectable 10ms/150ms (min) reset timeout, active-low push-pull reset output, and manual reset input - used to ensure reliable power-on reset and brownout protection in battery-powered medical and portable electronics.

For engineers reviewing the MAX6861UK16 datasheet, MAX6861UK16 pinout, MAX6861UK16 application, or MAX6861UK16 equivalent, key selection considerations include its CT-controlled dual reset timeout, guaranteed reset validity down to VCC = +1.1V, immunity to short VCC transients, and compatibility with low-voltage µP systems operating from 1.2V to 5.5V.

Technical Context

The MAX6861UK16 integrates voltage monitoring, manual reset assertion, and a fixed-function reset timeout generator - with no watchdog timer or WDI input. Its CT pin selects between two factory-programmed minimum timeout periods (D1 = 10ms or D3 = 150ms), enabling flexible system boot timing without external components.

Reset assertion occurs when VCC falls below 1.575V (±2.5%), MR is pulled low, or during power-up/brownout; reset remains asserted for the selected timeout after VCC rises above threshold and MR deasserts. The push-pull active-low RESET output drives directly into µP reset inputs without pullup resistors.

Key Specifications

Pinout & Package

Package: 5-pin SOT23-5, surface-mount, lead-free compatible (standard -T suffix).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3836K33 and MAX6361LUR29, MAX6861UK16 delivers 4.7× lower supply current than the former and adds MR functionality absent in the latter - making it optimal for long-life, serviceable, low-voltage portable designs.

Availability

MAX6861UK16 is available at Aetrix Electronics and suitable for portable medical devices, battery-powered IoT sensors, wearable health trackers, and industrial handheld terminals requiring stable component supply and long-term lifecycle support.

Supply support for MAX6861UK16 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) designs precision analog, mixed-signal, and power management ICs for demanding industrial, medical, and communications applications.

The MAX68xx family targets ultra-low-power microprocessor supervision in space-constrained, battery-critical systems - emphasizing nanopower operation, wide VCC range, and robust reset timing control.

FAQ

What is the exact reset threshold voltage of MAX6861UK16?

The MAX6861UK16 has a factory-trimmed reset threshold voltage of +1.575V, 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 "16" corresponds to 1.575V. The threshold remains stable across voltage and temperature, with normalized variation <±0.5% from −40°C to +85°C per typical characteristics graph.

How does the CT pin configure the reset timeout on MAX6861UK16?

On MAX6861UK16, the CT pin selects between two minimum reset timeout periods: connecting CT to GND selects D1 = 10ms (min), while connecting CT to VCC selects D3 = 150ms (min). These values are specified in Table 1 and electrical characteristics (tRP parameter). The timeout begins after VCC rises above 1.575V and MR deasserts, and the CT state is sampled at reset deassertion.

Does MAX6861UK16 include a watchdog timer function?

No, MAX6861UK16 does not include a watchdog timer. It belongs to the MAX6861/MAX6862/MAX6863 subgroup, which features only voltage monitoring, manual reset (MR), and pin-selectable reset timeout - no WDI input or watchdog circuitry. Watchdog capability is exclusive to MAX6864–MAX6869 variants, as confirmed in the Selector Guide and Pin Description sections.

What is the maximum sink current capability of the RESET output on MAX6861UK16?

The MAX6861UK16 RESET output (active-low push-pull) guarantees VOL ≤ 0.3V at ISINK = 50µA when VCC ≥ 1.1V and TA ≥ 0°C. At higher VCC (e.g., 2.5V), it sustains ≤0.3V at ISINK = 1.2mA. This allows direct interfacing with standard CMOS µP reset inputs without external pullups or level shifters.

Is MAX6861UK16 pin-compatible with other supervisory ICs?

Yes, MAX6861UK16 is pin-compatible with TPS3836/TPS3837/TPS3838 series per the datasheet Features section. All share identical 5-pin SOT23 layout (CT/MR/GND/RESET/VCC mapping), enabling drop-in replacement in existing designs - provided the reset threshold (1.575V), timeout configuration (CT-driven), and absence of watchdog functionality align with system requirements.