Texas Instruments TPS3851G50EDRBR

Overview

TPS3851G50EDRBR from Texas Instruments is a precision voltage supervisor IC with integrated watchdog timer, designed for system-level power monitoring and fault recovery in microcontroller-based applications. It delivers 0.8% undervoltage threshold accuracy (–40°C to +125°C), 200 ms reset timeout (±15%), and factory-programmed 1.6 s watchdog timeout (standard timing) - all within a 3 mm × 3 mm VSON-8 package. It supports 5.0 V rail supervision with 0.5% hysteresis and operates from 1.6 V to 6.5 V supply.

For engineers reviewing the TPS3851G50EDRBR datasheet, TPS3851G50EDRBR pinout, TPS3851G50EDRBR application, or TPS3851G50EDRBR equivalent, key selection considerations include its dual open-drain outputs (RESET and WDO), manual reset input (MR), watchdog disable via SET1, and capacitor-programmable or factory-set watchdog timing - critical for deterministic reset sequencing and fault isolation in safety-aware embedded systems.

Technical Context

The TPS3851G50EDRBR implements a high-accuracy comparator-based undervoltage detection circuit with 0.8% VITN tolerance over –40°C to +125°C and 0.5% hysteresis, enabling reliable operation on tight-tolerance 5.0 V rails. Its internal state machine evaluates CWD pin configuration (unconnected, 10 kΩ pullup, or capacitor-to-GND) at power-up to select between factory-programmed or user-adjustable watchdog timeouts.

It features independent open-drain RESET and WDO outputs, where WDO asserts only when RESET is deasserted - allowing fault signaling without triggering full system reset. The MR input provides asynchronous reset initiation, while SET1 enables dynamic watchdog enable/disable with 150 µs setup time, supporting development-mode bypass and production-mode supervision.

Key Specifications

Pinout & Package

TPS3851G50EDRBR is housed in a thermally enhanced 3.00 mm × 3.00 mm, 8-pin VSON package (DRB) with exposed thermal pad connected internally to GND. The package supports automated optical inspection and high-density PCB layouts.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar voltage supervisor with watchdog applications.

Compared with TPS3851G50EDRBR, the Q1 variant adds automotive qualification but no functional change, while MAX6375 offers lower cost and smaller size at the expense of 4.6× lower threshold accuracy and no watchdog capability - making TPS3851G50EDRBR optimal for precision 5.0 V supervision with fault-diagnostic flexibility.

Availability

TPS3851G50EDRBR is available at Aetrix Electronics and suitable for WLAN access points, wireless security cameras, IP network cameras, and string inverter control boards requiring stable component supply, long-term lifecycle support, and guaranteed traceability.

Supply support for TPS3851G50EDRBR 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

Texas Instruments is a global semiconductor company specializing in analog and embedded processing technologies, with leadership in power management, signal chain, and high-reliability ICs.

The TPS3851 product line delivers precision voltage supervision with integrated watchdog timers for mission-critical embedded systems - designed specifically for applications demanding deterministic reset behavior, fault isolation, and extended temperature operation without external timing components.

FAQ

What is the exact undervoltage threshold voltage of the TPS3851G50EDRBR?

The TPS3851G50EDRBR has a nominal undervoltage threshold (VITN) of 4.8 V, with ±0.8% accuracy over –40°C to +125°C. This is factory-trimmed to supervise 5.0 V rails with sufficient margin above typical microcontroller UVLO limits. The actual threshold is guaranteed between 4.7616 V and 4.8384 V at temperature extremes, per the SBVS300B datasheet revision June 2025.

Does the TPS3851G50EDRBR require external components to operate its watchdog timer?

No - the TPS3851G50EDRBR supports factory-programmed watchdog timing (1600 ms typical) with CWD left unconnected or pulled up to VDD via 10 kΩ. External capacitors are optional for adjustable timeouts. The device evaluates CWD configuration automatically at power-up in 381 µs, eliminating mandatory external parts for basic watchdog operation in the TPS3851G50EDRBR.

How does the WDO output behave relative to the RESET output on the TPS3851G50EDRBR?

On the TPS3851G50EDRBR, WDO asserts low only when RESET is high (deasserted). If RESET goes low (e.g., due to undervoltage), WDO enters high-impedance state regardless of watchdog status. This decoupling allows WDO to signal software faults independently - for example, logging a watchdog timeout while maintaining system reset state - a key differentiator from single-output supervisors.

Can the TPS3851G50EDRBR supervise voltages other than 5.0 V?

Yes - the TPS3851G50EDRBR is part of a family covering 1.8 V to 5.0 V thresholds, but this specific variant (G50) is fixed at 4.8 V. For other rails, TI offers variants like TPS3851G18 (1.728 V) or TPS3851G33 (3.168 V). The G50 suffix denotes the 5.0 V-compatible threshold; selecting another rail requires a different part number, not configuration.

What is the function of the SET1 pin on the TPS3851G50EDRBR?

The SET1 pin on the TPS3851G50EDRBR controls watchdog enable/disable: grounding SET1 disables the watchdog timer and ignores WDI input, while pulling it high enables normal watchdog operation. This allows hardware-level watchdog bypass during development or field updates. When disabled, WDI must be driven to VDD or GND to prevent increased supply current - a design requirement explicitly specified for the TPS3851G50EDRBR.