Analog Devices Inc./Maxim Integrated MAX16155DECC+T

Overview

MAX16155DECC+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 drops below 3.3V ±2.5%, and provides a 128s watchdog timeout with WD_EN control. Used in glucose monitors and portable medical devices requiring guaranteed firmware execution integrity.

For engineers reviewing the MAX16155DECC+T datasheet, MAX16155DECC+T pinout, MAX16155DECC+T application, or MAX16155DECC+T equivalent, key selection criteria include its 400nA typical supply current, factory-trimmed 3.3V reset threshold, 128ms reset timeout, 128s watchdog startup delay, and SOT23-6 package compatibility with manual reset–free, enable-controlled supervision.

Technical Context

The MAX16155DECC+T implements dual independent timing functions: a voltage-monitoring path with ±2.5% threshold accuracy across –40°C to +125°C, and a watchdog path featuring factory-set 128s startup delay and 128s timeout period. Its WD_EN input enables system-level control of watchdog activation, decoupling supervision from boot sequence timing.

Reset assertion follows VCC drop below 3.3V with 0.4% hysteresis; deassertion occurs after VCC rises above 3.304V and holds for 128ms. The watchdog ignores WDI transitions during RST assertion and startup delay, and requires valid low-to-high or high-to-low edges within the timeout window to prevent WDO pulse generation.

Key Specifications

Pinout & Package

MAX16155DECC+T is housed in a 6-pin SOT23 package (package code U6+1, outline 21-0058), with 1.27mm pitch, 2.9mm × 1.6mm 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 MAX16155DECC+T, MAX16153DECC+T trades WD_EN for MR-limiting flexibility in firmware-controlled supervision-while TPS3808G33DBVR omits both WD_EN and long-interval timing, reducing suitability for low-duty-cycle medical and metering applications.

Availability

MAX16155DECC+T is available at Aetrix Electronics and suitable for glucose monitors, patient vital sign loggers, and smart utility meters requiring stable component supply across extended product lifecycles and extreme temperature operation.

Supply support for MAX16155DECC+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 MAX16155DECC+T belongs to the nanoPower supervisor family, engineered specifically for battery-critical medical, metering, and IoT edge nodes where sub-μA quiescent current and long-interval watchdog supervision are mandatory.

FAQ

What is the factory-set reset threshold voltage for MAX16155DECC+T?

The MAX16155DECC+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 does not require external components or calibration. The threshold is fixed and cannot be adjusted; alternative thresholds (e.g., 1.8V, 2.5V, 5.0V) are available in other variants of the MAX16155 family, but MAX16155DECC+T is specifically configured for 3.3V operation.

How does the WD_EN pin function in MAX16155DECC+T?

In MAX16155DECC+T, the WD_EN pin is an active-high logic input that enables or disables the internal watchdog timer. When WD_EN is driven low, the watchdog circuit is fully disabled - WDI transitions are ignored, and WDO remains deasserted regardless of software activity. When WD_EN is pulled high, the watchdog starts after a 300μs setup time and begins monitoring WDI. This feature allows safe watchdog suspension during bootloader execution or firmware updates in the target microcontroller.

What are the timing values for reset timeout and watchdog timeout in MAX16155DECC+T?

The MAX16155DECC+T features a 128ms reset timeout period (tRP) and a 128s watchdog timeout period (tWD). Both are factory-configured and non-adjustable. The reset timeout ensures the microcontroller completes power-up initialization before RST deassertion. The 128s watchdog timeout aligns with long-duration sensor acquisition or communication cycles typical in medical and metering applications, and is paired with a matching 128s watchdog startup delay to avoid false timeouts during boot.

Can MAX16155DECC+T operate from a 1.8V supply?

Yes, MAX16155DECC+T operates from 1.2V to 5.5V, so it functions correctly at 1.8V. However, its reset threshold remains fixed at 3.3V - meaning it will assert RST whenever VCC falls below 3.3V. At 1.8V supply, the device will continuously assert reset and remain nonfunctional. Therefore, MAX16155DECC+T is intended for use with 3.3V (or higher) supply rails; for 1.8V systems, a variant with 1.8V threshold (e.g., MAX16155BCAA+T) must be selected.

What package type and footprint does MAX16155DECC+T use?

MAX16155DECC+T uses a 6-pin SOT23 package (outline number 21-0058, package code U6+1), measuring 2.9mm × 1.6mm with 1.27mm pin pitch. It is RoHS-compliant and tape-and-reel packaged (indicated by the "+T" suffix). The pinout is standardized: Pin 1 = VCC, Pin 2 = GND, Pin 3 = WDI, Pin 4 = WD_EN, Pin 5 = RST, Pin 6 = WDO - matching JEDEC MO-178AB and compatible with standard SOT23 reflow profiles.