Analog Devices Inc./Maxim Integrated MAX16155ABAD+T

Overview

MAX16155ABAD+T from Analog Devices is a nanoPower supervisory circuit with integrated watchdog timer, designed for ultra-low-power microcontroller-based systems. It monitors a single supply voltage (1.2V–5.5V), asserts an open-drain reset (RST) when VCC falls below a factory-trimmed threshold (±2.5% accuracy), and provides a 100ms nominal watchdog startup delay, 128ms reset timeout, and 128s watchdog timeout. It operates across –40°C to +125°C and is used in portable medical devices and battery-powered instrumentation.

For engineers reviewing the MAX16155ABAD+T datasheet, MAX16155ABAD+T pinout, MAX16155ABAD+T application, or MAX16155ABAD+T equivalent, this page delivers verified electrical parameters, SOT23-6 pin mapping, watchdog enable (WD_EN) behavior, reset timing accuracy, and real-world substitution guidance - all confirmed against Analog Devices' official documentation.

Technical Context

The MAX16155ABAD+T implements dual independent monitoring functions: a precision voltage supervisor with hysteresis (0.4% typical) and a configurable watchdog timer enabled via WD_EN. Its reset assertion logic responds to VCC falling below VTH, then holds RST active for 128ms after VCC rises above VTH + VHYS.

Watchdog operation requires periodic WDI transitions (low-to-high or high-to-low); failure to strobe within 128s triggers a 100–300ms open-drain WDO pulse. WD_EN must be driven high ≥300μs before watchdog monitoring begins, and glitch rejection on WD_EN is 300ns.

Key Specifications

Pinout & Package

MAX16155ABAD+T uses a 6-pin SOT23 package (package code U6+1, outline 21-0058), with 1.27mm × 2.2mm footprint and RoHS-compliant lead-free finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX16155ABAD+T, MAX16153ABAD+T trades WD_EN for MR - making it suitable for systems needing physical reset buttons but not runtime watchdog control; TPS3808G15DBVR omits watchdog entirely, reducing cost and complexity at the expense of system-level fault detection capability.

Availability

MAX16155ABAD+T is available at Aetrix Electronics and suitable for portable medical sensors, battery-powered meters, and industrial IoT edge nodes requiring stable component supply across extended temperature ranges and ultra-low power budgets.

Supply support for MAX16155ABAD+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

Analog Devices is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, automotive, communications, and healthcare markets.

The MAX16155ABAD+T belongs to the nanoPower Supervisor and Watchdog Timer product line, engineered specifically for energy-constrained, safety-critical embedded systems requiring guaranteed firmware execution monitoring and precise supply supervision.

FAQ

What is the factory-set reset threshold voltage for MAX16155ABAD+T?

The MAX16155ABAD+T has a factory-trimmed reset threshold of 1.5V, indicated by the 'A' in the part number suffix. This threshold is accurate to ±2.5% over the full –40°C to +125°C operating temperature range and 1.2V–5.5V supply range, eliminating need for external calibration components.

How does the WD_EN pin affect watchdog operation in MAX16155ABAD+T?

In MAX16155ABAD+T, WD_EN is an active-high enable input. When pulled low, the watchdog timer is fully disabled and ignores all WDI transitions. When driven high, the watchdog activates after a maximum 300μs setup time (tSETUP), and begins monitoring WDI for valid transitions within the 128s timeout window.

What is the reset timeout period for MAX16155ABAD+T, and how is it determined?

The MAX16155ABAD+T features a 128ms minimum reset timeout period (tRP), selected by the 'D' in the part number suffix per the Selector Guide. This fixed duration ensures the RST output remains asserted long enough for complete MCU initialization after VCC recovers above the 1.5V threshold plus hysteresis.

Can MAX16155ABAD+T operate from a 1.2V supply, and what is its supply current at that voltage?

Yes, MAX16155ABAD+T operates across 1.2V to 5.5V. Its typical supply current is 400nA at VCC = VTH + 150mV (i.e., 1.65V for the 1.5V threshold variant), and remains in the sub-μA range down to 1.2V - enabling use with depleted primary batteries and low-dropout regulators.

What are the key timing parameters for watchdog startup and timeout in MAX16155ABAD+T?

MAX16155ABAD+T has a 100ms nominal watchdog startup delay (tSTARTUP) and 128s nominal watchdog timeout (tWD). The startup delay begins after RST deassertion and ensures internal circuitry stabilizes before monitoring WDI; the timeout defines the maximum allowable interval between valid WDI transitions before WDO pulses low.