Analog Devices Inc./Maxim Integrated MAX6855UK20D6+T

Overview

The MAX6855UK20D6+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in a 5-pin SOT23 package, featuring ultra-low 170nA typical supply current, a factory-trimmed 2.0V reset threshold (±2.5%), and a 600ms–1200ms minimum reset timeout period (D6 option). It provides active-low push-pull reset output, manual reset input (MR), and operates across –40°C to +85°C for battery-powered medical and portable electronics.

For engineers reviewing the MAX6855UK20D6+T datasheet, MAX6855UK20D6+T pinout, MAX6855UK20D6+T application, or MAX6855UK20D6+T equivalent, this page delivers verified specifications, validated pin functions, confirmed reset timing behavior, and real-world use cases in glucose monitors and low-power embedded systems - all grounded in Maxim's official electrical characteristics and functional descriptions.

Technical Context

The MAX6855UK20D6+T implements a voltage-monitoring supervisory architecture with hysteresis (0.5% of V_TH) and guaranteed reset validity down to V_CC = 1.1V. Its internal MR pullup resistor is 10kΩ, and it features 250ns MR-to-reset delay with 1µs minimum MR pulse width and 200ns glitch rejection.

This variant belongs to the MAX6854–MAX6869 family but excludes watchdog timer (WDI) and CT select functionality. It uses a fixed D6 reset timeout (600–1200ms typ), active-low push-pull RESET output referenced to V_CC, and supports no external components beyond a recommended 0.1µF V_CC-to-GND bypass capacitor.

Key Specifications

Pinout & Package

MAX6855UK20D6+T is housed in a lead-free 5-pin SOT23-5 package (JEDEC MO-178AA), with 1.3mm × 2.9mm body and 0.95mm pitch. Pin 1 is marked with a dot; pin 1 is RESET, pin 2 and 4 are GND, pin 3 is MR, and pin 5 is V_CC.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3836K20DBVR and MAX6361KA20+T, the MAX6855UK20D6+T uniquely combines nanopower operation (170nA), MR support, push-pull output, and sub-1.1V reset validity - making it optimal for long-life, user-serviceable medical and portable electronics where every nanoamp matters.

Availability

MAX6855UK20D6+T is available at Aetrix Electronics and suitable for glucose monitors, patient monitors, MP3 players, and smart pagers requiring stable component supply, long-term lifecycle support, and lead-free compliance.

Supply support for MAX6855UK20D6+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 markets.

The MAX6854–MAX6869 product line was designed specifically for ultra-low-power microprocessor supervision in battery-critical portable and medical electronics, emphasizing nanoscale current consumption and robust reset timing.

FAQ

What is the exact reset threshold voltage of the MAX6855UK20D6+T?

The MAX6855UK20D6+T has a factory-trimmed reset threshold voltage of 2.0V with ±2.5% tolerance over temperature (–40°C to +85°C), as defined by the "20" suffix in its part number and confirmed in Table 2 of the Maxim datasheet. This value is measured during V_CC falling and applies to the device's primary V_CC monitoring function. The MAX6855UK20D6+T does not support adjustable thresholds or external reference inputs.

Does the MAX6855UK20D6+T include a watchdog timer function?

No, the MAX6855UK20D6+T does not include a watchdog timer. Per Maxim's Selector Guide and Pin Description tables, only MAX6864–MAX6869 variants feature WDI input functionality. The MAX6855UK20D6+T is a manual-reset-only supervisory circuit with MR input, RESET output, GND, and V_CC - no WDI or CT pins are present or functional on this specific part.

What is the meaning of the "D6" suffix in MAX6855UK20D6+T?

The "D6" suffix in MAX6855UK20D6+T specifies the reset timeout period option: D6 corresponds to a minimum reset timeout of 600ms, typical 900ms, and maximum 1200ms after V_CC rises above the 2.0V threshold or MR is deasserted. This value is fixed per device and cannot be altered externally - unlike MAX6861–MAX6863 which use the CT pin for selection.

Is the MAX6855UK20D6+T pin-compatible with other MAX68xx devices?

The MAX6855UK20D6+T shares the same 5-pin SOT23-5 package and pinout (RESET–GND–MR–GND–V_CC) with MAX6854, MAX6856, MAX6861, MAX6862, and MAX6863. However, it is not pin-compatible with MAX6858/MAX6860 (which have I.C. pins) or MAX6864–MAX6869 (which include WDI). Always verify functional compatibility - e.g., MAX6855UK20D6+T outputs active-low push-pull RESET, while MAX6854 may offer open-drain.

What is the guaranteed minimum V_CC level at which MAX6855UK20D6+T maintains valid RESET assertion?

The MAX6855UK20D6+T guarantees valid RESET assertion down to V_CC = 1.1V, as explicitly stated in the Electrical Characteristics table under "Guaranteed Reset Valid to V_CC = +1.1V". This ensures reliable reset hold during deep brownout conditions where many competing supervisors cease functioning - a key differentiator for medical and safety-critical portable applications.