Analog Devices Inc./Maxim Integrated MAX6855UK36D1+T

Overview

The MAX6855UK36D1+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 a factory-trimmed 3.600V reset threshold. It asserts reset during VCC brownout, MR assertion, or watchdog timeout (though MAX6855 lacks WDI), with a 10ms minimum reset timeout period and ultra-low 170nA typical supply current. It is used in battery-powered glucose monitors to ensure reliable µP initialization under low-voltage conditions.

For engineers reviewing the MAX6855UK36D1+T datasheet, MAX6855UK36D1+T pinout, MAX6855UK36D1+T application, or MAX6855UK36D1+T equivalent, key selection criteria include its 3.600V reset threshold accuracy (±2.5%), guaranteed reset validity down to VCC = +1.1V, 10ms reset timeout, MR glitch rejection (200ns), and compatibility with 1.2V–5.5V supply rails in portable medical electronics.

Technical Context

This device implements a precision voltage monitor with hysteresis (0.5% of VTH) and an internal reset timer that holds the active-high RESET output asserted for ≥10ms after VCC rises above 3.600V and MR is deasserted. Its MR input includes a 10kΩ internal pullup and supports CMOS-level drive with 1µs minimum pulse width.

The push-pull active-high RESET output delivers VOH ≥ 0.8×VCC (at ISOURCE = 500µA, VCC ≥ 2.38V) and VOL ≤ 0.3V (at ISINK = 1.2mA, VCC ≥ 2.38V), ensuring robust interfacing with µP reset inputs across its full 1.2V–5.5V operating range.

Key Specifications

Pinout & Package

5-pin SOT23-5 package with gull-wing leads, 1.6mm × 2.9mm footprint, 1.1mm max height, lead-free (RoHS-compliant) finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3836K33DBVR and MAX6361KA29D3+T, the MAX6855UK36D1+T offers the lowest ICC (170nA vs. µA-range), precise 3.600V threshold matching 3.6V systems, and validated MR noise immunity - critical for FDA-cleared portable diagnostics.

Availability

MAX6855UK36D1+T is available at Aetrix Electronics and suitable for glucose monitors, patient vital sign loggers, and handheld drug infusion pumps requiring stable component supply with long-term medical-grade lifecycle support.

Supply support for MAX6855UK36D1+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 industrial, medical, and communications applications, with emphasis on low-power, high-reliability solutions.

The MAX6854–MAX6869 family targets battery-constrained portable medical and consumer electronics, delivering nanopower supervision with configurable reset thresholds, timeouts, and output types - all in miniature SOT23 packages.

FAQ

What is the exact reset threshold voltage of the MAX6855UK36D1+T?

The MAX6855UK36D1+T has a factory-trimmed reset threshold of 3.600V, with guaranteed tolerance of ±2.5% over the full -40°C to +85°C operating temperature range. This value is confirmed in Table 2 (Threshold Suffix Guide) of the datasheet, where suffix "36" corresponds to 3.600V nominal. The MAX6855UK36D1+T uses this precise threshold to supervise 3.6V supply rails in portable medical devices without external calibration.

Does the MAX6855UK36D1+T include a watchdog timer function?

No, the MAX6855UK36D1+T does not include a watchdog timer. Per the Selector Guide and Pin Description sections, only MAX6864–MAX6869 variants feature WDI input; MAX6855 belongs to the MR-only subgroup (no WDI pin, no watchdog circuitry). The MAX6855UK36D1+T provides voltage monitoring, manual reset, and reset timing - making it ideal for applications requiring simplicity and ultra-low ICC without watchdog complexity.

What is the function of Pin 1 on the MAX6855UK36D1+T?

Pin 1 of the MAX6855UK36D1+T is the RESET output terminal, configured as an active-high push-pull driver. When asserted, it drives high (≥0.8×VCC) to hold the microprocessor in reset; when deasserted, it drives low (≤0.3V) to release reset. Unlike open-drain variants, this pin requires no external pullup and interfaces directly with µP reset inputs - a key design feature confirmed in the MAX6855-specific Pin Description table on page 7 of the datasheet.

What is the minimum reset timeout period for the MAX6855UK36D1+T?

The MAX6855UK36D1+T has a minimum reset timeout period of 10ms, corresponding to timeout option "D1" per Table 4 (Reset Timeout Periods). This duration ensures sufficient time for power rails and internal µP circuitry to stabilize before release. The timeout is factory-fixed and non-adjustable - consistent across all MAX6854/MAX6855/MAX6856/MAX6858/MAX6860 variants with D1 suffix, as verified in the Ordering Information and Electrical Characteristics tables.

Is the MAX6855UK36D1+T compatible with 1.8V logic systems?

Yes, the MAX6855UK36D1+T operates with VCC as low as 1.2V and guarantees valid RESET output down to VCC = +1.1V, making it fully compatible with 1.8V logic systems. Its VOH specification (≥0.8×VCC at ISOURCE = 500µA, VCC ≥ 2.38V) and VOL (≤0.3V at ISINK = 1.2mA, VCC ≥ 2.38V) meet standard 1.8V CMOS input thresholds. The device's 170nA ICC also ensures minimal loading on 1.8V LDOs in energy-sensitive designs.