Texas Instruments TPS3851G33EDRBT

Overview

TPS3851G33EDRBT 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 over –40°C to +125°C, 200 ms reset timeout (±15%), 10 µA quiescent current, and supports 3.3 V supply rails with 4% or 7% UVLO thresholds and 0.5% hysteresis - enabling reliable startup and brownout protection in industrial IoT edge nodes.

For engineers reviewing the TPS3851G33EDRBT datasheet, TPS3851G33EDRBT pinout, TPS3851G33EDRBT application, or TPS3851G33EDRBT equivalent, this page provides verified functional context, validated pin roles, confirmed timing parameters, real-world use cases in constrained-power embedded systems, and two technically documented alternative parts with explicit differences in threshold and watchdog configuration.

Technical Context

The TPS3851G33EDRBT implements a high-accuracy comparator-based undervoltage detection circuit with factory-trimmed reference and 0.5% hysteresis, ensuring stable reset assertion/deassertion across temperature and noise. Its dual-output architecture separates RESET (system reset) and WDO (watchdog fault flag), allowing independent handling of power faults versus software hangs.

Watchdog timing is configurable via CWD pin: open or pulled up enables factory-programmed 1600 ms (standard) or 200 ms (extended) timeouts; capacitor coupling enables user-adjustable timing using a 375 nA constant-current source charging CCWD to 1.21 V. SET1 disables the watchdog entirely, and MR provides hardware-initiated reset with internal pullup.

Key Specifications

Pinout & Package

TPS3851G33EDRBT uses an 8-pin VSON package (DRB), 3.00 mm × 3.00 mm body size, with exposed thermal pad connected internally to GND. The package supports high-density PCB layouts and efficient heat dissipation in thermally constrained enclosures.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3851G33EDRBT, the DBVR variant sacrifices watchdog flexibility and dual outputs for smaller size, while the TPS3850G33EDRBT removes factory timing and disable capability - making TPS3851G33EDRBT the only option supporting zero-layout-change migration between development (watchdog disabled), qualification (factory-timed), and field-deployed (capacitor-tuned) modes.

Availability

TPS3851G33EDRBT is available at Aetrix Electronics and suitable for industrial IoT gateways, smart metering systems, and automotive ADAS camera modules requiring stable component supply, long-term lifecycle assurance, and guaranteed traceable sourcing.

Supply support for TPS3851G33EDRBT 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 expertise in high-reliability supervisory circuits.

The TPS3851 product line was engineered specifically for next-generation microcontroller and SoC systems demanding simultaneous precision voltage monitoring and intelligent watchdog supervision in harsh thermal and electrical environments.

FAQ

What is the undervoltage threshold voltage for TPS3851G33EDRBT?

The TPS3851G33EDRBT is factory configured for a 3.3 V nominal supply rail with a 4% undervoltage threshold (VITN = 3.168 V) and 0.5% hysteresis. This yields a release point of 3.184 V, ensuring robust operation across voltage tolerances and temperature drift. Threshold accuracy remains ±0.8% over –40°C to +125°C.

How does the watchdog timeout work on TPS3851G33EDRBT?

The TPS3851G33EDRBT offers three watchdog timeout configurations: factory-programmed 1600 ms (standard) or 200 ms (extended) when CWD is open or pulled up to VDD via 10 kΩ, or user-adjustable timing via capacitor on CWD pin. SET1 enables/disables the watchdog; WDI requires falling-edge pulses before timeout expiration to prevent WDO assertion.

Can TPS3851G33EDRBT monitor multiple voltage rails?

No - the TPS3851G33EDRBT monitors only the VDD supply rail it is powered from. It does not include auxiliary voltage inputs or comparators for secondary rails. For multi-rail supervision, multiple TPS3851G33EDRBT units or a multi-channel supervisor like TPS386000 must be used.

What is the purpose of the SET1 pin on TPS3851G33EDRBT?

The SET1 pin on TPS3851G33EDRBT controls watchdog enable/disable: grounding SET1 disables the watchdog timer and causes WDI to be ignored, while pulling SET1 high enables normal watchdog operation. This allows safe development and debugging without unintended timeouts, and supports dynamic runtime control.

Is the thermal pad on TPS3851G33EDRBT required to be connected?

Yes - the exposed thermal pad on the TPS3851G33EDRBT VSON-8 package is internally connected to GND and must be soldered to a large-area PCB ground plane. Omitting this connection degrades thermal performance (RθJB increases from 25.8°C/W to >50°C/W) and risks exceeding junction temperature limits under sustained load.