Analog Devices Inc./Maxim Integrated MAX6361LUT26-T

Overview

MAX6361LUT26-T from Maxim Integrated is a low-power microprocessor supervisory circuit with factory-preset 2.63V reset threshold, manual reset input (MR), and active-low push-pull reset output. It operates from +1.2V supply, provides 150ms minimum reset timeout, supports battery switchover for SRAM backup, and is rated for -40°C to +85°C industrial temperature range.

For engineers reviewing the MAX6361LUT26-T datasheet, MAX6361LUT26-T pinout, MAX6361LUT26-T application, or MAX6361LUT26-T equivalent, key selection criteria include guaranteed reset assertion down to 1.2V VCC/VBATT, precision 2.63V ±1.5% threshold accuracy over temperature, debounced MR input with internal 20kΩ pull-up, and SOT23-6 package compatibility with space-constrained µP systems.

Technical Context

The MAX6361LUT26-T integrates a precision voltage monitor, debounced manual reset input with internal pull-up, and push-pull reset driver in a single BiCMOS IC. Its reset comparator uses a trimmed bandgap reference to achieve ±1.5% threshold accuracy across -40°C to +85°C, and the MR input includes built-in noise immunity via 100ns glitch rejection and 1µs minimum pulse width requirement.

It implements dual-supply operation: VCC powers the device and supplies OUT during normal operation; when VCC falls below 2.63V and VBATT exceeds VCC by ≥20mV, an internal MOSFET connects BATT to OUT for battery-backup mode. The push-pull RESET output drives µP reset pins directly without external pull-up resistors.

Key Specifications

Pinout & Package

Package: 6-pin SOT23 (U6-1), RoHS-compliant, footprint compatible with standard 0.95mm pitch land pattern (Maxim land pattern 90-0175).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6361PUT26-T, the MAX6361LUT26-T eliminates external pull-up components and simplifies layout; compared with TPS3808G26DBVR, it adds MR functionality and integrated battery switchover-critical for SRAM-retention designs-but consumes slightly higher quiescent current.

Availability

MAX6361LUT26-T is available at Aetrix Electronics and suitable for industrial control, portable medical devices, POS terminals, and smart sensor nodes requiring stable component supply and long-term manufacturability.

Supply support for MAX6361LUT26-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) designs precision analog and mixed-signal ICs for power, sensing, and interface applications in industrial, automotive, and communications markets.

The MAX6361–MAX6364 family was developed specifically for µP systems needing compact, low-power supervision with battery backup capability-targeting applications where SRAM data retention and deterministic reset timing are essential.

FAQ

What is the exact reset threshold voltage of the MAX6361LUT26-T?

The MAX6361LUT26-T has a factory-trimmed reset threshold of 2.63V, with guaranteed accuracy of ±1.5% over the full -40°C to +85°C operating temperature range. This value is laser-trimmed during production and does not require external calibration. The threshold is specified under conditions where VCC is falling at 10V/ms, and the device asserts reset when VCC drops below this level. The MAX6361LUT26-T maintains this specification across its entire supply range from +1.2V to +5.5V.

Does the MAX6361LUT26-T support battery backup switchover, and how does it work?

Yes, the MAX6361LUT26-T supports automatic battery backup switchover. When VCC falls below the 2.63V reset threshold and VBATT exceeds VCC by at least 20mV, an internal MOSFET connects the BATT pin to the OUT pin to power downstream circuitry such as SRAM. The device includes 40mV hysteresis to prevent oscillation during slow voltage transitions. In backup mode, the MAX6361LUT26-T draws less than 0.05µA from the battery (at TA = +25°C), preserving battery life. Note that the MAX6361LUT26-T does not provide a BATT ON indicator output-that function is exclusive to the MAX6363 variant.

What type of reset output does the MAX6361LUT26-T have, and what are its drive capabilities?

The MAX6361LUT26-T features an active-low push-pull reset output (pin 1). Unlike open-drain variants, it does not require an external pull-up resistor. It can sink up to 20mA while maintaining VOL ≤ 0.3V at VCC ≥ 2.1V, enabling direct interfacing with most µP reset inputs. The output remains asserted for a minimum of 150ms after VCC rises above 2.63V, after MR transitions high, or after power-up. This push-pull architecture simplifies design by eliminating external components and improves noise immunity in electrically noisy environments compared to open-drain configurations.

Can the manual reset input (MR) of the MAX6361LUT26-T be left unconnected, and what happens if it is?

Yes, the MR input of the MAX6361LUT26-T can be left unconnected because it includes an internal 20kΩ pull-up resistor to VCC. When left floating, MR remains at logic high and does not assert reset. If external control is not needed, the pin may be tied directly to VCC or left open. However, in noisy environments or when routing over long traces, Maxim recommends adding a 0.1µF capacitor from MR to GND for additional noise immunity. The MR input also features 100ns glitch rejection and requires a minimum 1µs pulse width to trigger reset, preventing false assertions from transient noise.

What is the minimum supply voltage at which the MAX6361LUT26-T guarantees proper reset assertion?

The MAX6361LUT26-T guarantees correct reset assertion down to +1.2V on either VCC or VBATT. This means that even as the main supply or backup battery decays to 1.2V, the internal comparator and reset driver remain functional and will hold the RESET output in the asserted (low) state until the supply recovers above the 2.63V threshold. This 1.2V operational floor is critical for applications requiring fail-safe behavior during deep brownouts or end-of-life battery conditions, and is explicitly tested and guaranteed across the full -40°C to +85°C temperature range.