Analog Devices Inc./Maxim Integrated MAX6855UK30D5+T

Overview

The MAX6855UK30D5+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in a 5-pin SOT23 package, featuring ultra-low 170nA typical supply current, factory-trimmed 3.000V reset threshold (suffix "30"), and 300ms minimum reset timeout (suffix "D5"). It provides active-high push-pull RESET output, manual reset input (MR), and operates across –40°C to +85°C for battery-powered portable electronics.

For engineers reviewing the MAX6855UK30D5+T datasheet, MAX6855UK30D5+T pinout, MAX6855UK30D5+T application, or MAX6855UK30D5+T equivalent, this device serves as a precision voltage monitor and reset controller where low quiescent current, guaranteed reset validity down to VCC = +1.1V, and immunity to short VCC transients are critical selection criteria.

Technical Context

The MAX6855UK30D5+T integrates a precision voltage comparator with ±2.5% threshold accuracy over temperature, a monolithic reset timeout timer with fixed 300ms (min) delay, and an internally pulled-up MR input (10kΩ). Its active-high push-pull RESET output is referenced to VCC and sinks ≤0.3V at 1.2mA load when asserted.

This variant belongs to the MAX6854–MAX6869 family but excludes watchdog timer (WDI) and CT select functionality - confirmed by its part number structure (no "S"/"L" suffix, no "CT" pin assignment) and Selector Guide entry. It asserts reset on VCC drop below 3.000V, MR assertion, or power-up/brownout, holding RESET high for ≥300ms after recovery.

Key Specifications

Pinout & Package

Package: 5-pin SOT23 (lead-free, +T suffix), 2.9mm × 1.6mm × 1.1mm body, gull-wing leads.

Key Features

Applications

Equivalent & Alternatives

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

Compared with the MAX6855UK30D5+T, the TPS3837K33DBVR offers higher drive strength but consumes ~7× more current, while the MAX6361KA29D3+T trades MR functionality and ultra-low ICC for lower unit cost - making the MAX6855UK30D5+T optimal for long-life, feature-complete supervisory needs.

Availability

MAX6855UK30D5+T is available at Aetrix Electronics and suitable for portable medical devices, battery-powered IoT sensors, wearable fitness trackers, and industrial handheld terminals requiring stable component supply across extended product lifecycles.

Supply support for MAX6855UK30D5+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, mixed-signal, and power management ICs for demanding industrial, medical, and communications applications.

The MAX6854–MAX6869 family was engineered specifically for ultra-low-power microprocessor supervision in battery-critical systems, emphasizing nanoscale current consumption, guaranteed low-voltage operation, and minimal external component count.

FAQ

What is the exact reset threshold voltage of the MAX6855UK30D5+T?

The MAX6855UK30D5+T has a factory-trimmed reset threshold voltage of 3.000V, with guaranteed tolerance of ±2.5% over the full operating temperature range (–40°C to +85°C). This value is defined by the "30" suffix in the part number and is confirmed in Table 2 (Threshold Suffix Guide) of the datasheet. The threshold remains stable across VCC from 1.2V to 5.5V.

Does the MAX6855UK30D5+T include a watchdog timer function?

No, the MAX6855UK30D5+T does not include a watchdog timer. Its part number lacks the "S" or "L" watchdog timeout suffix found in MAX6864–MAX6869 variants, and the Selector Guide explicitly lists WDI as "-" for MAX6855. The MAX6855UK30D5+T provides only voltage monitoring, manual reset (MR), and fixed reset timeout - no watchdog input or timing circuitry is present.

What is the function of Pin 4 on the MAX6855UK30D5+T?

Pin 4 on the MAX6855UK30D5+T is a second GND terminal, electrically connected to Pin 2 internally. This dual-GND configuration improves noise immunity, enhances thermal performance, and reduces ground bounce in high-speed or noisy environments. Both pins must be connected to the same system ground plane per the recommended layout in the datasheet.

Can the MAX6855UK30D5+T operate with a 1.8V supply?

Yes, the MAX6855UK30D5+T operates with VCC as low as 1.2V and guarantees valid reset assertion down to VCC = +1.1V. At 1.8V, its typical supply current is 170nA, and its RESET output maintains VOH ≥ 0.8×VCC (≥1.44V) when deasserted and VOL ≤ 0.3V when asserted under specified load conditions - fully compatible with 1.8V logic interfaces.

Is the MAX6855UK30D5+T pin-compatible with other SOT23 supervisory ICs?

The MAX6855UK30D5+T uses a standard 5-pin SOT23 footprint and shares identical pin assignments (RESET, GND, MR, GND, VCC) with the MAX6854/MAX6856 series and pin-compatible parts like the TPS3836/TPS3837/TPS3838 family. However, electrical behavior differs - e.g., MAX6855UK30D5+T outputs active-high RESET, whereas TPS3837K33DBVR outputs active-low open-drain - requiring schematic review before substitution.