Diodes Incorporated PT7M823LW5-7

Overview

PT7M823LW5-7 from Diodes Incorporated is a precision μP supervisor IC with 4.63V reset threshold, 200ms reset pulse width, push-pull RESET output, and integrated watchdog timer. It monitors VCC during power-up/down/brownout, asserts active-low reset for microprocessor initialization, and supports manual reset via debounced MR input. Used in embedded systems requiring reliable power-on sequencing and fault recovery.

For engineers reviewing the PT7M823LW5-7 datasheet, PT7M823LW5-7 pinout, PT7M823LW5-7 application, or PT7M823LW5-7 equivalent, key selection criteria include reset threshold accuracy (±2% over -40°C to +85°C), guaranteed RESET validity down to VCC = 1.0V, watchdog timeout of 1.6s typical, and SOT25 package compatibility with space-constrained PCB layouts.

Technical Context

The PT7M823LW5-7 implements a precision bandgap-based voltage monitor with 0.8% hysteresis to prevent chatter near the 4.63V reset threshold. Its internal watchdog timer clears on any WDI edge and triggers reset if WDI remains static for ≥1.6s, enabling detection of firmware lockup in microcontrollers.

Reset assertion is synchronized to VCC transitions: RESET goes low when VCC falls below VRST and remains low for ≥200ms after VCC rises above VRST. The MR input features an internal 52kΩ pull-up resistor and supports noise-immune manual reset with <100ns glitch rejection.

Key Specifications

Pinout & Package

SOT25 (5-pin small outline transistor) package: 2.8mm × 2.9mm footprint, 1.0mm height, gull-wing leads, RoHS-compliant lead-free finish.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar μP supervisor applications.

Compared with MAX809TRD3T and TPS3808G33DBVR, the PT7M823LW5-7 uniquely combines 4.63V precision monitoring, integrated watchdog, debounced MR, and push-pull drive in a single SOT25 package-enabling compact, self-contained reset supervision for 5V microprocessor systems without external components.

Availability

PT7M823LW5-7 is available at Aetrix Electronics and suitable for industrial PLC controllers, network infrastructure equipment, and server baseboard management requiring stable component supply and long-term lifecycle support.

Supply support for PT7M823LW5-7 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, specializing in high-reliability power management, signal integrity, and protection solutions for industrial and computing markets.

The PT7M823/824/825 family targets microprocessor-based systems needing accurate, low-power, and feature-rich power supervision - designed specifically to replace discrete reset circuits in embedded, networking, and storage applications.

FAQ

What is the minimum VCC required for PT7M823LW5-7 to assert a valid RESET signal?

The PT7M823LW5-7 guarantees RESET output validity down to VCC = 1.0V, meaning it can detect brownout conditions and maintain a logic-low RESET state even as the supply voltage collapses below normal operating levels. This capability is confirmed in the DC Electrical Characteristics table under "Guaranteed RESET/RESET Valid at VCC = 1V" and applies across the full -40°C to +85°C temperature range.

How does the watchdog timer interact with the manual reset (MR) input?

The watchdog timer clears whenever RESET is asserted - including during manual reset events. When MR is pulled low and released, the resulting RESET pulse resets the watchdog counter, preventing spurious timeout resets during intentional system resets. This ensures that firmware supervision resumes cleanly after user-initiated recovery without requiring additional WDI toggles.

Can the PT7M823LW5-7 be used with a 3.3V microprocessor system?

Yes - although its reset threshold is 4.63V, the PT7M823LW5-7 operates from VCC = 1.0V to 5.5V and delivers a valid push-pull RESET signal compatible with 3.3V logic families. It is commonly used in mixed-rail systems where a 5V supervisor monitors the main power rail while controlling a 3.3V microprocessor's /RESET input via level-compatible output drive.

Is the WDI input internally pulled up or down when left unconnected?

The WDI input has no internal pull-up or pull-down resistor. When left unconnected (floating), the internal watchdog circuit detects this condition and automatically disables the watchdog function - as documented in the Functional Description section. This allows safe omission of external biasing components when watchdog supervision is not required.