Diodes Incorporated PT7M7812LTBEX

Overview

PT7M7812LTBEX from Diodes Incorporated is a precision μP supervisor IC with manual reset and watchdog timer functionality, designed for reliable power-on reset assertion in microprocessor systems. It features a 4.63V reset threshold (L suffix), 200ms reset pulse width, active-low push-pull RESET output, and operates down to VCC = 1.0V - enabling robust brownout detection in embedded industrial controllers and networked edge devices.

For engineers reviewing the PT7M7812LTBEX datasheet, PT7M7812LTBEX pinout, PT7M7812LTBEX application, or PT7M7812LTBEX equivalent, key selection criteria include its SOT143-4 package compatibility, guaranteed RESET validity at 1.0V supply, debounced MR input with internal 10–40kΩ pull-up, and dual-trigger reset (power-fail + watchdog) for fail-safe firmware recovery in server management controllers and security system SoCs.

Technical Context

The PT7M7812LTBEX implements a voltage-monitoring circuit with hysteresis (±2.5% over –40°C to +85°C) and a 1.6s watchdog timeout period, triggered by WDI edge transitions. Its reset generator asserts RESET low during power-up until VCC exceeds 4.63V and remains asserted for ≥200ms after threshold crossing.

It integrates a debounced CMOS-compatible manual-reset input (MR) with internal pull-up (10–40kΩ), and supports both power-fail warning and watchdog-initiated reset via dedicated WDI pin - all while maintaining guaranteed RESET/RESET logic states down to VCC = 1.0V.

Key Specifications

Pinout & Package

SOT143-4 (TB) package: 4-pin surface-mount plastic package with 1.3mm × 1.3mm footprint, 0.65mm pitch, and exposed pad for thermal performance in space-constrained designs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX809SEUR+T and TPS3808G33DBVR, PT7M7812LTBEX uniquely combines 4.63V precision monitoring, integrated MR pull-up, and dual-trigger (WDI + MR) reset in SOT143-4 - making it optimal for compact, feature-complete reset supervision in 5V industrial SoCs where board space and functional completeness are constrained.

Availability

PT7M7812LTBEX is available at Aetrix Electronics and suitable for industrial PLC controllers, network switch management units, security system SoC modules, and embedded storage controllers requiring stable component supply and long-term lifecycle support.

Supply support for PT7M7812LTBEX 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, computing, and communications markets.

PT7M7812LTBEX belongs to the PT7M78xx family of μP supervisors - engineered specifically to reduce component count and improve power-supply reliability in microprocessor-based systems with demanding brownout and watchdog requirements.

FAQ

What is the guaranteed minimum VCC level at which RESET remains valid?

RESET output is guaranteed valid down to VCC = 1.0V, as confirmed in the datasheet's "Guaranteed RESET/RESET valid at VCC=1.0V" description and DC Electrical Characteristics table. This ensures reliable reset assertion during deep brownout conditions before logic corruption occurs.

Does PT7M7812LTBEX require an external pull-up resistor on the MR pin?

No. The MR pin includes an internal pull-up resistor of 10–40kΩ, as specified in the DC Electrical Characteristics table under "r MR pull-up resistor". This eliminates the need for external components in manual-reset button circuits.

Is the RESET output push-pull or open-drain?

PT7M7812LTBEX features a push-pull RESET output, confirmed by the Function Comparison Table (row 5) and Pin Configuration diagrams showing RESET as active-low push-pull. This differs from PT7M7803 (open-drain) and enables direct drive of CMOS inputs without external pull-ups.

Can the watchdog timer be disabled without modifying the PCB?

Yes. The watchdog function is automatically disabled when the WDI pin is left unconnected or driven by a high-impedance (three-state) buffer, per the Pin Description section. No solder jumper or configuration register is required - simplifying field updates and test modes.