Analog Devices Inc./Maxim Integrated MAX6831YHUT

Overview

MAX6831YHUT from Maxim Integrated is an ultra-low-voltage dual microprocessor supervisory circuit in SOT23-6 package, monitoring primary supply (VCC) and secondary supply (VCC2) with factory-trimmed 1.313V ±3% VCC2 threshold and 2.93V ±3% VCC threshold, featuring open-drain active-low RESET output, manual reset input (MR), watchdog timer (1.6s nominal timeout), and guaranteed reset validity down to VCC = +1.0V - used in battery-powered embedded controllers requiring reliable brownout detection and system recovery.

For engineers reviewing the MAX6831YHUT datasheet, MAX6831YHUT pinout, MAX6831YHUT application, or MAX6831YHUT equivalent, key selection considerations include its open-drain RESET output compatibility with bidirectional µP reset pins, dual-supply monitoring capability (VCC up to +5.0V, VCC2 down to +0.9V), 140ms minimum reset timeout, immunity to short negative VCC transients, and operation across –40°C to +125°C industrial temperature range.

Technical Context

The MAX6831YHUT implements a dual-threshold supervision architecture: one comparator monitors VCC against a fixed 2.93V threshold (suffix 'S'), while a second comparator monitors VCC2 against a factory-trimmed 1.313V threshold (suffix 'H'). Its internal watchdog timer triggers reset if WDI remains static beyond 1.6s, and resets on any rising or falling edge - cleared automatically during RESET assertion or MR activation.

Reset assertion occurs when VCC < 2.93V, VCC2 < 1.313V, MR is pulled low, or watchdog times out; RESET remains asserted for ≥140ms after all conditions clear. The open-drain RESET output requires external pullup and supports bidirectional µP interfaces like Motorola 68HC11, with VOL ≤ 0.4V at ISINK = 3.2mA and leakage ≤1.0µA when deasserted.

Key Specifications

Pinout & Package

MAX6831YHUT is housed in a 6-pin SOT23-6 package (JEDEC MO-178AA), 2.9mm × 1.6mm × 1.1mm, with gull-wing leads and exposed pad not present. Pin 1 is marked by a dot or beveled corner.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-supply microprocessor supervision applications.

Compared with MAX6831YHUT, MAX6829YHUT offers identical supervision accuracy but eliminates external pullup requirement at the cost of µP interface flexibility, while TPS3808G125DBVR reduces feature set to basic single-rail monitoring - making MAX6831YHUT the only option supporting simultaneous VCC/VCC2 supervision, watchdog, and open-drain reset in SOT23-6.

Availability

MAX6831YHUT is available at Aetrix Electronics and suitable for portable/battery-powered equipment, automotive body control modules, and industrial sensor nodes requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6831YHUT 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 and mixed-signal ICs for power, sensing, and interface applications, with emphasis on high-reliability industrial and automotive solutions.

The MAX6826–MAX6831 family was engineered specifically for multivoltage embedded systems needing compact, dual-rail supervision with watchdog safety - targeting space-constrained, battery-sensitive applications where discrete supervision would increase cost and failure risk.

FAQ

What is the exact VCC and VCC2 reset threshold voltage for MAX6831YHUT?

The MAX6831YHUT has a VCC reset threshold of 2.93V ±3% (suffix 'S') and a VCC2 reset threshold of 1.313V ±3% (suffix 'H'), both factory-trimmed and specified over –40°C to +125°C. These values are confirmed in the Threshold Suffix Guide and Electrical Characteristics table of the MAX6831YHUT datasheet, with typical hysteresis of 2×VTH mV ensuring clean release without chatter during voltage recovery.

Does MAX6831YHUT support operation below 1.8V VCC?

Yes, MAX6831YHUT is fully specified for VCC = +1.53V to +2.0V (per Electrical Characteristics table), and guaranteed to assert valid reset down to VCC = +1.0V. This enables use in ultra-low-voltage systems such as energy-harvesting nodes or deep-sleep MCU applications where supply rails drop below 1.8V during quiescent states.

Can MAX6831YHUT monitor a 1.2V supply as VCC2?

Yes, MAX6831YHUT's VCC2 input is factory-trimmed to 1.313V ±3%, making it suitable for monitoring 1.2V supplies with margin - the device asserts reset when VCC2 falls below 1.27V (min) at +125°C. No external resistor divider is needed, unlike adjustable supervisors, simplifying design for fixed-core-rail monitoring.

What is the watchdog timeout behavior of MAX6831YHUT?

The MAX6831YHUT features a nominal 1.6s watchdog timeout period, with min/max limits of 0.80s to 2.60s over –40°C to +125°C. The internal timer clears on any WDI edge (rising or falling), MR assertion, or RESET activation - ensuring immediate recovery from stuck firmware loops without requiring precise pulse timing.

Is MAX6831YHUT pin-compatible with other devices in the MAX6826–MAX6831 family?

Yes, all MAX6826–MAX6831 variants share identical SOT23-6 pinout and footprint, including MAX6831YHUT. Pin functions (VCC, GND, MR, WDI, VCC2, RESET) are consistent across the family - allowing direct substitution between versions differing only in reset type (open-drain vs. push-pull) or threshold values, provided PCB layout accommodates the chosen RESET drive method.