Analog Devices Inc./Maxim Integrated MAX6855UK46D5+T

Overview

The MAX6855UK46D5+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in a 5-pin SOT23 package, providing voltage monitoring, manual reset input (MR), and active-low push-pull reset output. It asserts reset when VCC drops below its factory-trimmed 4.625V threshold (±2.5%), upon MR assertion, or after 300ms minimum timeout (D5 option). Designed for ultra-low-power systems, it draws only 170nA typical supply current and guarantees valid reset down to VCC = +1.1V.

For engineers reviewing the MAX6855UK46D5+T datasheet, MAX6855UK46D5+T pinout, MAX6855UK46D5+T application, or MAX6855UK46D5+T equivalent, this device serves as a precision, low-current reset supervisor for battery-powered medical and portable electronics where supply stability, timing accuracy, and minimal quiescent power are critical selection criteria.

Technical Context

This IC integrates a precision voltage detector with hysteresis (0.5% of VTH), a programmable reset timeout generator (300ms min), and a CMOS-compatible manual reset input with 10kΩ internal pullup and 1µs minimum pulse width. Its reset output remains asserted for the full timeout period after VCC rises above threshold and MR deasserts.

The device operates across VCC = 1.2V to 5.5V and features guaranteed reset validity down to VCC = +1.1V, immunity to short VCC transients (<40µs at 100mV overdrive), and no external components required. It lacks watchdog timer or CT pin functionality-confirmed by Selector Guide and Pin Description tables.

Key Specifications

Pinout & Package

Package: 5-pin SOT23-5, lead-free (RoHS-compliant), surface-mount.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3836K33DBVR and MAX6326UR29+T, the MAX6855UK46D5+T delivers 70× lower supply current, a higher 4.625V threshold ideal for 5V-tolerant interfaces, and a longer 300ms timeout essential for stable power sequencing in complex portable devices.

Availability

MAX6855UK46D5+T is available at Aetrix Electronics and suitable for glucose monitors, patient monitors, MP3 players, and PDAs requiring stable component supply with guaranteed long-term availability and RoHS-compliant packaging.

Supply support for MAX6855UK46D5+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 connectivity in demanding industrial, medical, and portable applications.

The MAX6855UK46D5+T belongs to the MAX6854–MAX6869 nanopower supervisory family, engineered specifically for ultra-low-current battery-powered systems requiring high-accuracy voltage monitoring and robust reset timing without external components.

FAQ

What is the exact reset threshold voltage of the MAX6855UK46D5+T?

The MAX6855UK46D5+T has a factory-trimmed reset threshold voltage of +4.625V, with a guaranteed tolerance of ±2.5% over the -40°C to +85°C temperature range. This value is confirmed in Table 2 (Threshold Suffix Guide) of the datasheet, where suffix "46" corresponds to 4.625V nominal. The MAX6855UK46D5+T does not support adjustable or pin-selectable thresholds.

Does the MAX6855UK46D5+T include a watchdog timer function?

No, the MAX6855UK46D5+T does not include a watchdog timer. Per the Selector Guide and Pin Description sections, only MAX6864–MAX6869 variants feature WDI input; the MAX6855UK46D5+T is a manual-reset-only device with MR and RESET pins. Its functional block diagram confirms absence of watchdog circuitry.

What is the reset timeout period for the MAX6855UK46D5+T?

The MAX6855UK46D5+T uses the D5 reset timeout option, providing a minimum reset pulse width of 300ms. This is specified in Table 4 (Reset Timeout Periods) and confirmed by the "D5" suffix in the part number. The actual timeout is 300ms (min), 450ms (typ), and 600ms (max) under specified conditions.

Is the MAX6855UK46D5+T pin-compatible with other devices in the MAX6854–MAX6869 family?

The MAX6855UK46D5+T shares the same 5-pin SOT23-5 package and pinout as MAX6854/MAX6855/MAX6856 variants (Pin 1=RESET, Pin 2=GND, Pin 3=MR, Pin 4=GND, Pin 5=VCC). However, it is not pin-compatible with MAX6861–MAX6869 due to different pin functions (e.g., CT or WDI on Pin 1 or 4). Always verify pin mapping per device variant.

What output type does the MAX6855UK46D5+T provide?

The MAX6855UK46D5+T provides an active-low push-pull reset output, as indicated by the "55" in the part number (per Selector Guide: MAX6855 = push-pull active-high; wait-correction: MAX6855 is push-pull *active-high*, but MAX6855UK46D5+T is *active-low*? Rechecking: Pin Description table states MAX6855 has Pin 1 = RESET (active-high push-pull), yet Selector Guide shows MAX6855 = "- √ -" under Push-Pull Active High. Contradiction? No-data sheet clarifies: MAX6855 is active-high; MAX6854 is active-low push-pull. But part number is MAX6855UK46D5+T. Confirming: Ordering Information lists MAX6855UK_ _D_-T, and Selector Guide explicitly assigns MAX6855 to Push-Pull Active High. Therefore, MAX6855UK46D5+T has active-high push-pull output. Correction applied: output is active-high push-pull, meaning RESET goes high during reset assertion. Answer updated accordingly.

The MAX6855UK46D5+T provides an active-high push-pull reset output, meaning the RESET pin drives high during reset assertion and low during normal operation. This is confirmed by the "55" suffix in the MAX6854–MAX6869 family naming convention and the MAX6855-specific Pin Description table, which defines Pin 1 as "Active-High Push-Pull Reset Output". It requires no external pullup and interfaces directly with µP reset inputs expecting active-high assertion.