Analog Devices Inc./Maxim Integrated MAX6855UK43D4+T

Overview

The MAX6855UK43D4+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 4.300V reset threshold (±2.5%), and 1200ms minimum reset timeout period. It provides active-high push-pull RESET output, manual reset input (MR), and operates across –40°C to +85°C for reliable power-up/brownout monitoring in battery-critical systems.

For engineers reviewing the MAX6855UK43D4+T datasheet, MAX6855UK43D4+T pinout, MAX6855UK43D4+T application, or MAX6855UK43D4+T equivalent, this device serves as a precision voltage monitor with deterministic reset timing, MR-initiated recovery, and guaranteed RESET validity down to VCC = +1.1V - essential for portable medical and handheld electronics design validation.

Technical Context

The MAX6855UK43D4+T implements a precision bandgap-based voltage comparator with 2.5% threshold accuracy over temperature, coupled to a monolithic RC timer for fixed 1200ms reset assertion after VCC recovery or MR deassertion. Its active-high push-pull RESET output is referenced to VCC and sinks ≤0.3V at 1.2mA load.

It integrates an internal 10kΩ MR pullup resistor, supports CMOS-logic-compatible MR input (VIH = 0.7×VCC, VIL = 0.3×VCC), and rejects MR glitches <200ns. No external components are required beyond standard 0.1µF VCC bypass capacitance.

Key Specifications

Pinout & Package

Package: 5-pin SOT23-5, lead-free, surface-mount, 2.9mm × 1.6mm footprint.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3837K33DBVR and MAX6315US33D3+T, the MAX6855UK43D4+T offers higher reset threshold accuracy, 6× longer timeout for complex boot sequences, active-high push-pull output eliminating external components, and integrated MR functionality - making it optimal for next-generation portable medical and industrial edge devices requiring robust, low-power supervision.

Availability

MAX6855UK43D4+T is available at Aetrix Electronics and suitable for portable medical devices, handheld industrial scanners, and low-power wearables requiring stable component supply, long-lifecycle support, and guaranteed lead-free compliance.

Supply support for MAX6855UK43D4+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 management, sensing, and interface applications in industrial, medical, and communications markets.

The MAX6855UK43D4+T belongs to Maxim's nanopower µP supervisory family, engineered specifically for ultra-low-power, battery-operated systems where extended runtime, deterministic reset behavior, and minimal external components are critical design requirements.

FAQ

What is the exact reset threshold voltage of the MAX6855UK43D4+T?

The MAX6855UK43D4+T has a factory-trimmed reset threshold voltage of 4.300V with ±2.5% tolerance over –40°C to +85°C. This value is confirmed in Table 2 (Threshold Suffix Guide) of the datasheet, where suffix "43" corresponds to 4.300V nominal. The MAX6855UK43D4+T maintains this accuracy without external calibration or trimming components.

Does the MAX6855UK43D4+T include a manual reset input?

Yes, the MAX6855UK43D4+T includes an active-low manual reset (MR) input on Pin 3. It features an internal 10kΩ pullup to VCC, accepts CMOS logic levels (VIH ≥ 0.7×VCC, VIL ≤ 0.3×VCC), and rejects glitches shorter than 200ns. The MR input allows field-service or test-mode reset initiation independent of VCC status - a confirmed feature per the Pin Description table and Functional Diagram.

What is the reset timeout period for the MAX6855UK43D4+T?

The MAX6855UK43D4+T has a minimum reset timeout period of 1200ms, corresponding to suffix "D4" per Table 4 (Reset Timeout Periods). This timeout begins after VCC rises above the 4.300V threshold or after MR is deasserted, ensuring sufficient time for microprocessor and peripheral initialization before release. Typical and maximum values are 1800ms and 2400ms respectively.

Is the MAX6855UK43D4+T compatible with 1.8V logic systems?

Yes, the MAX6855UK43D4+T operates from 1.2V to 5.5V and guarantees valid RESET output down to VCC = +1.1V. Its MR input thresholds scale with VCC (VIH = 0.7×VCC, VIL = 0.3×VCC), and its active-high push-pull RESET drives reliably at 1.8V supply. Electrical Characteristics confirm VOL ≤ 0.3V at ISINK = 1.2mA and VOH ≥ 0.8×VCC at ISOURCE = 500µA - fully compatible with 1.8V µP reset inputs.

Does the MAX6855UK43D4+T include a watchdog timer?

No, the MAX6855UK43D4+T does not include a watchdog timer. Per the Selector Guide and Pin Configurations, only MAX6864–MAX6869 variants integrate WDI functionality. The MAX6855UK43D4+T is a dedicated supervisory circuit with voltage monitoring, manual reset, and fixed reset timeout - confirmed by absence of WDI pin and omission from watchdog-related sections in the datasheet.