Diodes Incorporated PT7M7812STBEX

Overview

PT7M7812STBEX from Diodes Incorporated is a precision microprocessor (μP) supervisor IC with 4.38V reset threshold, 200ms reset pulse width, debounced manual-reset input, and watchdog timer functionality. It monitors V_CC in embedded μP systems, asserts active-low RESET during power-up/brownout, and supports manual reset and watchdog timeout detection (1.6s typical). Used in server power management for reliable cold-start sequencing.

For engineers reviewing the PT7M7812STBEX datasheet, PT7M7812STBEX pinout, PT7M7812STBEX application, or PT7M7812STBEX equivalent, key selection criteria include reset threshold accuracy (±2.5% over –40°C to +85°C), SOT143-4 package compatibility, MR internal pull-up (10–40kΩ), and guaranteed RESET validity down to V_CC = 1.0V.

Technical Context

The PT7M7812STBEX implements dual supervision logic: voltage monitoring via precision bandgap-based threshold detection (VRST = 4.38V nominal) and watchdog timing based on an internal RC oscillator (t_WD = 1.6s typ). It combines manual-reset assertion with automatic brownout response without requiring external components.

Its functional architecture includes independent MR and WDI inputs, push-pull RESET output, and hysteresis (VRTH = 50mV typ) to prevent chatter near threshold. The device operates across 1.0V–5.5V supply range and guarantees valid reset signaling even at V_CC = 1.0V - critical for low-voltage SoC power sequencing.

Key Specifications

Pinout & Package

SOT143-4 package: 4-pin surface-mount plastic package with 1.3mm × 1.3mm footprint, 0.65mm pitch, and exposed pad for thermal performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with PT7M7812STBEX, MAX809SEUR+T omits MR/WDI functionality and uses a higher threshold (4.63V), while TPS3808G12DBVR trades integration for configurability - making PT7M7812STBEX optimal for compact, feature-complete 5V μP supervision.

Availability

PT7M7812STBEX is available at Aetrix Electronics and suitable for server/storage power sequencing, industrial PLC controllers, network switch ASIC boot, and medical diagnostic edge devices requiring stable component supply and long-term lifecycle support.

Supply support for PT7M7812STBEX 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.

The PT7M78xx family targets μP system reliability with integrated voltage monitoring, watchdog, and manual reset - designed specifically for industrial, networking, and embedded applications demanding precision and minimal external components.

FAQ

What is the exact reset threshold voltage for PT7M7812STBEX?

The PT7M7812STBEX has a nominal reset threshold voltage of 4.38V, with ±2.5% tolerance over the full operating temperature range (–40°C to +85°C). This value is laser-trimmed during production and specified in the DC Electrical Characteristics table under VRST parameter for the 'M' suffix variant.

Does PT7M7812STBEX support watchdog functionality?

Yes - PT7M7812STBEX includes a built-in watchdog timer with 1.6s typical timeout (1.12–2.25s range). It monitors the WDI input and triggers RESET if no edge transition occurs within that period. WDI is present on the SOT143-4 package as a dedicated pin, confirmed in the Pin Configuration diagram and Function Comparison Table.

What package type does PT7M7812STBEX use, and what are its key mechanical features?

PT7M7812STBEX uses the SOT143-4 package: a 4-pin, 1.3mm × 1.3mm surface-mount plastic package with 0.65mm lead pitch and gull-wing leads. Its small footprint and thermal characteristics support high-density PCB layouts in space-constrained applications like network switches and portable medical devices.

Can PT7M7812STBEX operate reliably at V_CC = 1.0V?

Yes - the datasheet explicitly guarantees valid RESET/RESET output behavior down to V_CC = 1.0V. This is verified in the "Description" section and DC Electrical Characteristics table, enabling robust operation during deep brownout conditions where other supervisors may fail to assert reset.