Texas Instruments TPS3851G33SDRBR

Overview

TPS3851G33SDRBR 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 timing via external capacitor or factory-set defaults. Its open-drain RESET and WDO outputs support tight-tolerance rails including 3.3V systems.

For engineers reviewing the TPS3851G33SDRBR datasheet, TPS3851G33SDRBR pinout, TPS3851G33SDRBR application, or TPS3851G33SDRBR equivalent, this page provides verified functional context, validated pin roles, confirmed timing parameters, and real-world deployment guidance for industrial and embedded power supervision.

Technical Context

The TPS3851G33SDRBR implements a high-accuracy comparator with 0.5% hysteresis and a dedicated state machine for independent watchdog timing control. Its dual-output architecture separates RESET assertion (for full system reset) from WDO assertion (for fault logging without reset), enabling selective fault response in safety-critical firmware.

Watchdog timeout is determined either by internal factory programming (1600 ms typical, ±15%) or externally via CWD pin capacitor (0.1–1000 nF), with SET1 pin enabling/disabling and WDI pin accepting falling-edge triggers. All timing functions operate only when VDD exceeds VITN + VHYST (3.465 V for 3.3V threshold variant).

Key Specifications

Pinout & Package

TPS3851G33SDRBR uses an 8-pin VSON package (3.00 mm × 3.00 mm) with exposed thermal pad connected internally to GND. The package supports reflow soldering per JEDEC J-STD-020 and achieves 25.8°C/W junction-to-board thermal resistance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3851G33QDRBRQ1, the TPS3851G33SDRBR omits AEC-Q100 testing but retains identical timing, accuracy, and pinout-making it optimal for industrial use. Against MAX6373KA33+T, it adds programmable watchdog and 3× better threshold accuracy at marginally higher quiescent current.

Availability

TPS3851G33SDRBR is available at Aetrix Electronics and suitable for WLAN access points, wireless security cameras, IP network cameras, and solar string inverter control units requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for TPS3851G33SDRBR 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 IC design.

The TPS3851 family was developed to address demand for high-accuracy, dual-output supervisors in industrial and communications infrastructure-specifically targeting systems needing independent reset and watchdog signaling without firmware dependency.

FAQ

What is the undervoltage threshold voltage for TPS3851G33SDRBR?

The TPS3851G33SDRBR has a nominal undervoltage threshold (V_ITN) of 3.3 V, with ±0.8% accuracy over –40°C to +125°C. This value is factory-trimmed and applies specifically to the G33 variant; other variants (e.g., G18, G50) have different thresholds. The device also provides 0.5% hysteresis (16.5 mV) to prevent chatter during supply transients.

How does the watchdog timeout work on TPS3851G33SDRBR?

The TPS3851G33SDRBR supports two watchdog timeout modes: factory-programmed (1600 ms typical, ±15%) when CWD is unconnected or pulled up to VDD via 10 kΩ, and user-adjustable via capacitor on CWD (0.1–1000 nF). The SET1 pin enables or disables the watchdog entirely; WDI must receive a falling edge before t_WD(min) to prevent WDO assertion.

Can TPS3851G33SDRBR monitor supplies other than 3.3V?

Yes-the TPS3851G33SDRBR monitors its own VDD supply, which can range from 1.6 V to 6.5 V. While its 3.3 V threshold targets 3.3 V rails, it supports supervision of any rail within that voltage range, including 1.8 V, 2.5 V, and 5.0 V systems, provided the monitored voltage is applied directly to VDD and falls within recommended operating conditions.

What is the function of the SET1 pin on TPS3851G33SDRBR?

The SET1 pin on TPS3851G33SDRBR controls watchdog enable/disable: grounding SET1 disables the watchdog timer and causes WDI to be ignored, while pulling SET1 high enables normal watchdog operation. When disabled, WDI must be driven to VDD or GND to avoid increased supply current; the pin supports dynamic toggling with a 150 µs setup time before watchdog responsiveness resumes.

Is TPS3851G33SDRBR pin-compatible with other TPS3851 variants?

Yes-TPS3851G33SDRBR shares identical 8-pin VSON (DRB) packaging and pinout with all TPS3851 variants (e.g., TPS3851G18SDRBR, TPS3851G50SDRBR). Threshold voltage, hysteresis, and factory-programmed watchdog timing differ by suffix, but mechanical fit, thermal pad layout, and electrical pin functions remain fully interchangeable in PCB design.