Analog Devices Inc./Maxim Integrated MAX16155DDCD+T

Overview

MAX16155DDCD+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 (1.2V–5.5V), asserts an open-drain reset (RST) when VCC falls below 3.3V ±2.5%, and provides a 128s watchdog timeout with 64s startup delay-enabling reliable fault detection in battery-powered medical and portable devices.

For engineers reviewing the MAX16155DDCD+T datasheet, MAX16155DDCD+T pinout, MAX16155DDCD+T application, or MAX16155DDCD+T equivalent, this device delivers verified 400nA typical supply current, factory-trimmed 3.3V reset threshold, 6-pin SOT23 package compatibility, and WD_EN-controlled watchdog enable/disable functionality critical for power-constrained embedded safety monitoring.

Technical Context

The MAX16155DDCD+T implements a dual-function architecture: a precision voltage monitor with ±2.5% threshold accuracy across –40°C to +125°C, and a configurable watchdog timer with independent startup (64s nominal) and timeout (128s nominal) periods. Its WD_EN input enables dynamic watchdog activation during system sleep modes without requiring external logic.

Reset assertion is triggered on VCC drop below 3.3V, followed by a 128ms minimum reset timeout after VCC recovery; the open-drain RST and WDO outputs require external pullups and support direct interfacing with µP reset and NMI inputs. The device uses internal hysteresis (0.4% of VTH) to prevent chatter during slow-rising VCC transitions.

Key Specifications

Pinout & Package

MAX16155DDCD+T is housed in a 6-pin SOT23 package (package code U6+1, outline 21-0058), optimized for space-constrained PCB layouts and reflow-compatible assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX16153DDCD+T and TPS3808G33DBVR, the MAX16155DDCD+T uniquely combines factory-trimmed 3.3V supervision, 128s configurable watchdog, and hardware WD_EN control-making it the only option supporting adaptive watchdog behavior in long-duration, battery-powered medical and metering systems.

Availability

MAX16155DDCD+T is available at Aetrix Electronics and suitable for portable medical devices, smart utility meters, and industrial handheld testers requiring stable component supply, extended temperature operation, and ultra-low quiescent current performance.

Supply support for MAX16155DDCD+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 MAX16155DDCD+T belongs to the nanoPower supervisor family, engineered specifically for battery-operated diagnostic, metering, and portable instrumentation where sub-1µA supply current and guaranteed reset timing are mandatory.

FAQ

What is the factory-set reset threshold voltage for MAX16155DDCD+T?

The MAX16155DDCD+T has a factory-trimmed reset threshold of 3.3V with ±2.5% accuracy over –40°C to +125°C. This value is laser-trimmed during production and cannot be adjusted externally. The threshold applies to VCC monitoring and determines both the undervoltage reset assertion point and the hysteresis level (0.4% of VTH).

How does the WD_EN pin affect watchdog operation in MAX16155DDCD+T?

In MAX16155DDCD+T, WD_EN is an active-high logic input that enables or disables the internal watchdog timer. When WD_EN is low, the watchdog ignores all WDI transitions and remains inactive; when pulled high, the watchdog starts after a 300μs setup time and begins monitoring WDI. This allows firmware to gate watchdog supervision during safe operational phases like bootloader execution or firmware updates.

What is the watchdog timeout period for MAX16155DDCD+T, and how is it configured?

The MAX16155DDCD+T features a nominal watchdog timeout period of 128 seconds, factory-configured per the "D" suffix in its ordering code. Unlike adjustable watchdog ICs, this value is fixed at wafer-level trimming and requires no external components or register writes. The timeout begins after the watchdog startup delay (64s nominal) completes and WDI has not received a valid transition.

Can MAX16155DDCD+T operate from a 1.8V supply?

Yes, MAX16155DDCD+T operates across 1.2V to 5.5V, including 1.8V. At 1.8V, the 3.3V reset threshold remains valid-meaning the device will assert RST if VCC falls below 3.3V, but since 1.8V < 3.3V, RST stays asserted continuously. Therefore, MAX16155DDCD+T is only functional as a supervisor when VCC ≥ 3.3V; for lower-supply systems, a different threshold variant (e.g., MAX16155BCAA+T, 1.8V threshold) must be selected.

What package type and footprint does MAX16155DDCD+T use?

MAX16155DDCD+T uses a standard 6-pin SOT23 package (outline 21-0058, package code U6+1), with 0.95mm pin pitch and 2.9mm × 1.6mm body dimensions. It shares footprint compatibility with industry-standard SOT23-6 devices and supports conventional reflow soldering per JEDEC J-STD-020. Land pattern number 90-0175 applies.