Texas Instruments TPS3851H33EDRBT

Overview

TPS3851H33EDRBT from Texas Instruments is a precision voltage supervisor IC with integrated watchdog timer, designed for microcontroller and SoC power-rail monitoring in industrial and embedded systems. 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.

For engineers reviewing the TPS3851H33EDRBT datasheet, TPS3851H33EDRBT pinout, TPS3851H33EDRBT application, or TPS3851H33EDRBT equivalent, this page provides verified functional roles, factory-programmed watchdog timing options, open-drain RESET/WDO outputs, MR input support, and VSON-8 package integration details critical for power sequencing, fault detection, and system reliability validation.

Technical Context

The TPS3851H33EDRBT implements a high-accuracy comparator-based undervoltage detection circuit with 0.8% VITN tolerance and 0.5% hysteresis, enabling robust operation in tight-tolerance systems. Its dual-mode watchdog uses either factory-programmed delays (1600 ms standard, 200 ms extended) or user-adjustable capacitor timing via the CWD pin.

RESET and WDO are independent open-drain outputs with separate assertion logic: RESET responds to VDD falling below VITN, while WDO asserts only when watchdog timeout occurs and RESET is deasserted. The SET1 pin enables dynamic watchdog disable, and MR provides external manual reset initiation with internal pullup.

Key Specifications

Pinout & Package

TPS3851H33EDRBT is housed in a 3.00 mm × 3.00 mm, 8-pin VSON (DRB) package with exposed thermal pad connected internally to GND. The package supports high-density PCB layouts and efficient thermal dissipation via soldered thermal pad connection to ground plane.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3851G33EDRBT and MAX6373KA33+T, the TPS3851H33EDRBT uniquely combines 0.8% accuracy, dual-mode watchdog (1600 ms / 200 ms), independent WDO, and MR input in a single VSON-8 device-enabling both high-reliability power monitoring and granular fault diagnostics without additional ICs.

Availability

TPS3851H33EDRBT is available at Aetrix Electronics and suitable for WLAN access points, wireless security cameras, IP network cameras, and string inverter control units requiring stable component supply, long-term lifecycle assurance, and automotive-grade temperature performance.

Supply support for TPS3851H33EDRBT 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 industrial and automotive IC design.

The TPS3851 family is engineered for mission-critical power supervision in systems where deterministic reset behavior, watchdog fault isolation, and wide-temperature operation are mandatory-targeting industrial automation, smart energy, and edge-connected devices.

FAQ

What is the undervoltage threshold voltage for TPS3851H33EDRBT?

The TPS3851H33EDRBT 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 precise 3.168 V trip point with 15.84 mV hysteresis window, ensuring clean reset assertion and deassertion without oscillation on noisy 3.3 V rails. The threshold is guaranteed at ±0.8% over –40°C to +125°C.

Does TPS3851H33EDRBT support user-programmable watchdog timeout?

Yes, TPS3851H33EDRBT supports user-programmable watchdog timeout via the CWD pin: connecting a capacitor from CWD to GND enables adjustable timing using tWD = 3.23 × CCWD + 0.381 ms (standard) or tWD = 28.9 × CCWD + 62.7 ms (extended). Alternatively, leaving CWD unconnected or pulling it to VDD with 10 kΩ selects factory-programmed 1600 ms or 200 ms timeouts.

What is the function of the SET1 pin on TPS3851H33EDRBT?

The SET1 pin on TPS3851H33EDRBT controls watchdog enable/disable: grounding SET1 disables the watchdog timer entirely, causing WDI to be ignored and WDO to remain high-impedance. When SET1 is high, the watchdog operates normally. This feature allows safe development-mode operation without unintended resets and supports dynamic watchdog control in runtime firmware.

Can TPS3851H33EDRBT monitor supply rails other than 3.3 V?

Yes, TPS3851H33EDRBT can monitor any rail from 1.8 V to 5.0 V because its VDD pin serves as both supply and monitored input. While the "H33" suffix indicates factory programming for 3.3 V applications (4% or 7% UVLO), the underlying architecture supports accurate supervision of 1.8 V, 2.5 V, 3.0 V, and 5.0 V rails-verified by TI's VITN accuracy data across all thresholds in the datasheet.

What package type and thermal characteristics does TPS3851H33EDRBT use?

TPS3851H33EDRBT uses the DRB (VSON-8) package: 3.00 mm × 3.00 mm body with exposed thermal pad. Its thermal metrics include RθJA = 50.7°C/W and RθJB = 25.8°C/W, enabling reliable operation at full junction temperature (125°C) with minimal PCB copper area. The thermal pad must be soldered to a large-area ground plane per TI layout guidelines.