Analog Devices Inc./Maxim Integrated MAX6855UK23D5+T

Overview

The MAX6855UK23D5+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in a 5-pin SOT23 package, featuring active-high push-pull reset output, manual reset input (MR), and factory-trimmed 2.313V reset threshold. It delivers ultra-low 170nA typical supply current, guarantees reset validity down to VCC = +1.1V, and provides a 300ms minimum reset timeout period. It is designed for reliable power-on/power-down/brownout monitoring in battery-critical portable systems.

For engineers reviewing the MAX6855UK23D5+T datasheet, MAX6855UK23D5+T pinout, MAX6855UK23D5+T application, or MAX6855UK23D5+T equivalent, key selection criteria include its active-high push-pull RESET logic, 2.313V threshold accuracy (±2.5%), 300ms timeout (D5 option), immunity to sub-40µs VCC transients, and guaranteed operation across –40°C to +85°C.

Technical Context

This device implements a precision voltage monitor with hysteresis (0.5% of VTH), a digital reset timeout timer, and an MR input with 250ns propagation delay and 1µs minimum pulse width. Its internal 10kΩ MR pullup enables direct switch interfacing without external components.

The MAX6855UK23D5+T belongs to the MAX6854–MAX6869 family and lacks watchdog (WDI) or timeout-select (CT) pins - it is a fixed-threshold, fixed-timeout, MR-enabled supervisory IC with push-pull active-high RESET output only.

Key Specifications

Pinout & Package

Package: 5-pin SOT23-5, lead-free, surface-mount.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3837K23DBVR and MAX6361KA23D3+T, the MAX6855UK23D5+T uniquely combines ultra-low 170nA ICC, active-high push-pull RESET (no pullup needed), and precise 2.313V/300ms configuration - making it optimal for new designs prioritizing battery longevity and simplified layout.

Availability

MAX6855UK23D5+T is available at Aetrix Electronics and suitable for portable medical devices, wearable health monitors, industrial handheld terminals, and low-power IoT sensors requiring stable component supply across extended production lifecycles.

Supply support for MAX6855UK23D5+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 industrial, medical, and communications applications.

The MAX6854–MAX6869 product line was engineered specifically for nanopower supervisory functions in battery-powered portable equipment - delivering precision voltage monitoring, manual reset, and configurable timing in minimal footprint.

FAQ

What is the exact reset threshold voltage of the MAX6855UK23D5+T?

The MAX6855UK23D5+T has a factory-trimmed reset threshold of 2.313V, 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 "23" corresponds to 2.313V nominal. The MAX6855UK23D5+T maintains valid reset assertion down to VCC = +1.1V, ensuring robustness during deep brownout conditions.

Does the MAX6855UK23D5+T include a watchdog timer function?

No, the MAX6855UK23D5+T does not include a watchdog timer. It belongs to the MAX6854/MAX6855/MAX6856 subgroup, which supports only voltage monitoring and manual reset (MR) - no WDI pin or watchdog circuitry. Watchdog capability is exclusive to MAX6864–MAX6869 variants, identifiable by "S" or "L" suffixes in the ordering code. The MAX6855UK23D5+T pinout confirms absence of WDI.

What does the "D5" in MAX6855UK23D5+T indicate?

The "D5" suffix in MAX6855UK23D5+T specifies the reset timeout period: D5 = 300ms minimum timeout (with typical 450ms and max 600ms). This is defined in Table 4 (Reset Timeout Periods) of the datasheet. The timeout begins after VCC rises above the 2.313V threshold and MR is deasserted, ensuring sufficient hold time for µP initialization before release.

Is the MAX6855UK23D5+T pin-compatible with other MAX68xx supervisory ICs?

The MAX6855UK23D5+T shares the same 5-pin SOT23-5 package and pinout (RESET, GND, MR, GND, VCC) with MAX6854, MAX6856, MAX6861–MAX6863, and MAX6864–MAX6869 - but functional compatibility depends on reset polarity and features. Unlike MAX6854 (active-low push-pull) or MAX6856 (open-drain), the MAX6855UK23D5+T provides active-high push-pull RESET, requiring logic-level verification before substitution.

What is the supply current specification for the MAX6855UK23D5+T under normal operation?

The MAX6855UK23D5+T draws 170nA typical supply current (ICC) at +25°C with VCC = 2.5V and no load - confirmed in the Electrical Characteristics table. At full temperature range (–40°C to +85°C), ICC remains ≤400nA. This ultra-low quiescent current is critical for multi-year battery operation in devices like glucose monitors and wireless sensors, where the MAX6855UK23D5+T contributes negligible drain.