Texas Instruments TPS3851G25EDRBR

Overview

TPS3851G25EDRBR 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 user-programmable watchdog timeout via external capacitor or factory-set values. Its dual open-drain outputs (RESET and WDO) support independent fault signaling in industrial IoT gateways and smart meters.

For engineers reviewing the TPS3851G25EDRBR datasheet, TPS3851G25EDRBR pinout, TPS3851G25EDRBR application, or TPS3851G25EDRBR equivalent, this page provides verified functional specifications, validated pin functions, confirmed thermal and timing behavior, and real-world implementation context for reliable BOM selection and schematic integration.

Technical Context

The TPS3851G25EDRBR implements a high-accuracy comparator with 0.5% hysteresis on its undervoltage detection path, enabling stable operation in noisy supply environments. Its internal state machine evaluates the CWD pin configuration (capacitor, 10kΩ pullup, or open) within 381 µs after VDD enters the valid operating range (VITN + VHYST).

It supports two watchdog timing modes: standard (e.g., 1600 ms typical) and extended (e.g., 77.45 s typical), selected via SET1 logic level and CWD configuration. The WDO output remains high-impedance when RESET is asserted, allowing independent watchdog fault flagging without triggering full system reset.

Key Specifications

Pinout & Package

TPS3851G25EDRBR uses an 8-pin VSON package (DRB), 3.00 mm × 3.00 mm body size, with exposed thermal pad internally connected to GND. The package supports high-density PCB layouts and efficient heat dissipation in thermally constrained designs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3851G18EDRBR and TPS3851G33EDRBR, the TPS3851G25EDRBR provides exact 2.5 V threshold matching for systems using 2.5 V logic or analog rails - avoiding design margin loss or unnecessary derating that occurs when substituting non-matching threshold variants.

Availability

TPS3851G25EDRBR is available at Aetrix Electronics and suitable for industrial IoT gateways, smart energy meters, and medical diagnostics equipment requiring stable component supply, long-lifecycle support, and guaranteed traceability.

Supply support for TPS3851G25EDRBR 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 leader specializing in analog, embedded processing, and power management technologies, with decades of experience in high-reliability supervisory circuits.

The TPS3851 family was engineered to address demand for precision, low-power, and feature-rich voltage supervision in safety-critical and thermally demanding applications - particularly where independent watchdog signaling and tight threshold accuracy are mandatory.

FAQ

What is the undervoltage threshold voltage for TPS3851G25EDRBR?

The TPS3851G25EDRBR has a factory-programmed undervoltage threshold (VITN) of 2.5 V, with ±0.8% accuracy over –40°C to +125°C. This value is laser-trimmed during production and applies specifically to the 'G25' variant - other suffixes (e.g., G18, G33) denote different fixed thresholds. The 2.5 V threshold ensures compatibility with common 2.5 V logic rails and ADC reference supplies.

How does the watchdog timeout work on TPS3851G25EDRBR?

The TPS3851G25EDRBR supports two watchdog timeout configurations: factory-programmed (1600 ms typical when CWD is open and SET1 = 1) or user-adjustable via external capacitor on CWD. The watchdog asserts WDO low upon timeout only if RESET is high; it ignores WDI pulses when RESET is low. A 150 µs setup time applies when enabling watchdog via SET1 transition.

Can TPS3851G25EDRBR monitor multiple supply rails simultaneously?

No - the TPS3851G25EDRBR monitors only the VDD supply rail applied to its Pin 1. It does not support multi-rail monitoring. For systems requiring supervision of >1 rail, multiple TPS3851G25EDRBR units or a multi-channel supervisor (e.g., TPS386000) must be used. Each device independently controls its own RESET and WDO outputs based on its local VDD.

What is the purpose of the SET1 pin on TPS3851G25EDRBR?

The SET1 pin on TPS3851G25EDRBR enables hardware-level watchdog disable: grounding SET1 disables the watchdog function entirely, causing WDI to be ignored and WDO to remain high-impedance. This is used during firmware development or safe-mode operation. When SET1 is high, watchdog operation resumes normally - including response to WDI pulses and timeout assertion on WDO.

Is TPS3851G25EDRBR compatible with 1.8 V logic interfaces?

Yes - the TPS3851G25EDRBR supports VDD as low as 1.6 V and accepts logic inputs (MR, SET1, WDI) with VIH = 0.8 V and VIL = 0.25 V, making it interoperable with 1.8 V GPIOs. Its open-drain outputs (RESET, WDO) can be pulled up to any voltage ≤6.5 V, enabling level-shifting to 1.8 V, 3.3 V, or 5 V domains without additional circuitry.