Analog Devices Inc./Maxim Integrated MAX6861UK17+T

Overview

MAX6861UK17+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in 5-pin SOT23 package, featuring ultra-low 170nA typical supply current, factory-trimmed 1.623V reset threshold (suffix '17'), and pin-selectable 10ms/150ms minimum reset timeout via CT input. It monitors VCC, responds to manual reset (MR), and asserts active-low push-pull RESET for reliable power-up/brownout recovery in battery-powered medical and portable electronics.

For engineers reviewing the MAX6861UK17+T datasheet, MAX6861UK17+T pinout, MAX6861UK17+T application, or MAX6861UK17+T equivalent, key selection criteria include its 1.623V threshold accuracy, CT-configurable reset delay, guaranteed RESET validity down to VCC = +1.1V, immunity to short VCC transients, and compatibility with low-voltage µP systems requiring <200nA quiescent current.

Technical Context

The MAX6861UK17+T integrates voltage monitoring, manual reset detection, and a precision reset timeout generator-without watchdog timer or WDI functionality. Its internal comparator continuously compares VCC against the factory-trimmed 1.623V threshold (±2.5% over temperature), triggering RESET assertion on VCC drop or MR low pulse.

Reset deassertion follows a fixed or CT-selected timeout (10ms or 150ms min) after VCC rises above threshold and MR releases. The push-pull active-low RESET output drives directly into µP reset inputs without external pullup, sinking ≥50µA at 0.3V with VCC ≥1.1V.

Key Specifications

Pinout & Package

MAX6861UK17+T uses a 5-pin SOT23 package with exposed pad (not electrically connected). Pin 1 is CT (Reset Timeout Select), Pin 2 is GND, Pin 3 is MR (Manual Reset), Pin 4 is RESET (active-low push-pull), and Pin 5 is VCC. All pins support operation down to 1.1V VCC.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3836K33DBVR and MAX6315US29D3+, the MAX6861UK17+T delivers 10× lower supply current, a 1.623V threshold optimized for modern low-voltage MCUs, and field-configurable reset timing-making it uniquely suited for energy-critical medical and portable designs.

Availability

MAX6861UK17+T is available at Aetrix Electronics and suitable for glucose monitors, patient monitors, smart wearables, and industrial handheld terminals requiring stable component supply with long-term lifecycle assurance.

Supply support for MAX6861UK17+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 demanding industrial, medical, and communications applications.

The MAX6861UK17+T belongs to Maxim's nanopower µP supervisory family, designed specifically for battery-operated medical devices and portable electronics where ultra-low ICC, precise low-voltage monitoring, and configurable reset timing are critical.

FAQ

What is the exact reset threshold voltage of MAX6861UK17+T?

The MAX6861UK17+T has a factory-trimmed reset threshold voltage of 1.623V, with ±2.5% tolerance over the full -40°C to +85°C temperature range. This value is confirmed in Table 2 (Threshold Suffix Guide) of the datasheet, where suffix '17' corresponds to 1.623V (min 1.583V, typ 1.623V, max 1.665V). The threshold remains stable across VCC from 1.2V to 5.5V.

How does the CT pin configure the reset timeout period on MAX6861UK17+T?

The CT pin on MAX6861UK17+T selects between two minimum reset timeout periods: connecting CT to GND selects 10ms (D1), while connecting CT to VCC selects 150ms (D3). This is defined in Table 1 and the MAX6861/MAX6862/MAX6863 Pin Description section. The timeout begins after VCC rises above threshold and MR deasserts, and the CT state is sampled at reset deassertion.

Does MAX6861UK17+T include a watchdog timer function?

No, MAX6861UK17+T does not include a watchdog timer. It belongs to the MAX6861–MAX6863 subgroup, which features manual reset (MR) and CT-selectable timeout but omits the WDI input and watchdog circuitry found in MAX6864–MAX6869 variants. The functional diagram (Figure 1) and Selector Guide confirm absence of WDI pin and watchdog block.

What is the maximum VCC transient duration that MAX6861UK17+T can ignore without asserting reset?

MAX6861UK17+T is immune to VCC transients ≤40µs in duration when the overdrive is 100mV (i.e., VCC falls from VTH + 100mV to below VTH). This is derived from the "Maximum VCC Transient Duration vs. Reset Threshold Overdrive" graph (MAX684 toc05) in the datasheet. Shorter transients or smaller magnitudes are tolerated; longer ones may trigger false reset.

Is MAX6861UK17+T pin-compatible with other supervisory ICs?

Yes, MAX6861UK17+T is pin-compatible with the TPS3836/TPS3837/TPS3838 series per the Features section, sharing identical 5-pin SOT23 pinout (CT=MR position, GND, MR=CT position, RESET, VCC). However, function mapping differs: CT on MAX6861UK17+T replaces the WDI or I.C. pin on other variants, so PCB layout reuse requires verification of signal routing and net connectivity.