Texas Instruments TPS3851G33SDRBT

Overview

TPS3851G33SDRBT 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% undervoltage threshold and 0.5% hysteresis - enabling reliable startup and brownout protection in wireless security cameras and IP network cameras.

For engineers reviewing the TPS3851G33SDRBT datasheet, TPS3851G33SDRBT pinout, TPS3851G33SDRBT application, or TPS3851G33SDRBT equivalent, key selection considerations include factory-programmed watchdog timing (1600 ms typ), open-drain RESET/WDO outputs, manual reset input (MR), SET1-controlled watchdog enable/disable, and VSON-8 package compatibility with tight-layout embedded designs.

Technical Context

The TPS3851G33SDRBT implements a high-accuracy comparator-based undervoltage detection circuit with 0.8% VITN tolerance and 0.5% hysteresis, ensuring stable reset assertion/deassertion across industrial temperature ranges. Its dual-output architecture separates RESET (system reset) and WDO (watchdog fault flag) functions, allowing independent fault signaling without full system reset.

Watchdog timing is configurable via CWD pin: unconnected or pulled up enables factory-programmed 1600 ms (typ) timeout (standard timing), while capacitor coupling enables user-adjustable delays. SET1 disables watchdog logic entirely, and WDI accepts falling-edge-triggered pulses with 150 µs setup time after watchdog enable.

Key Specifications

Pinout & Package

TPS3851G33SDRBT is housed in a 3.00 mm × 3.00 mm, 8-pin VSON package (DRB) with exposed thermal pad connected internally to GND. The package supports high-density PCB layouts and provides efficient thermal dissipation (RθJB = 25.8°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3851G33QDBVR, the TPS3851G33SDRBT offers identical performance at lower cost and qualification tier, while MAX6373KA33+T sacrifices watchdog programmability and accuracy for reduced size and BOM count - making TPS3851G33SDRBT optimal for industrial IoT where configurability and precision are prioritized.

Availability

TPS3851G33SDRBT is available at Aetrix Electronics and suitable for wireless security cameras, IP network cameras, and string inverter control boards requiring stable component supply, long-term manufacturability, and guaranteed traceable sourcing.

Supply support for TPS3851G33SDRBT 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 real-time control ICs.

The TPS3851 product line delivers high-accuracy, integrated supervisory solutions for mission-critical embedded systems - specifically engineered to replace discrete reset ICs and external watchdog timers in space-constrained, thermally demanding applications.

FAQ

What is the undervoltage threshold voltage for TPS3851G33SDRBT?

The TPS3851G33SDRBT is factory configured for a 3.3 V nominal supply rail with a 4% undervoltage threshold, resulting in VITN = 3.168 V (3.3 V × 0.96). This value is trimmed to ±0.8% accuracy across –40°C to +125°C, meaning the actual threshold falls between 3.142 V and 3.194 V under full temperature range.

Does TPS3851G33SDRBT support both standard and extended watchdog timing modes?

No - TPS3851G33SDRBT implements standard timing mode only. Extended timing (e.g., up to 77 seconds) is available in variants suffixed with 'E' (e.g., TPS3851G33E), whereas TPS3851G33SDRBT uses the 'S' suffix denoting standard timing, with factory-programmed watchdog timeout of 1600 ms (typical) when CWD is unconnected and SET1 is high.

How is the watchdog timer disabled on TPS3851G33SDRBT?

The watchdog timer on TPS3851G33SDRBT is disabled by grounding the SET1 pin. When SET1 = 0 V, the watchdog logic is halted, WDI is ignored, and WDO remains in high-impedance state. During disable, WDI must be actively driven to VDD or GND to prevent increased supply current (IDD).

What is the function of the CWD pin on TPS3851G33SDRBT?

The CWD pin on TPS3851G33SDRBT selects watchdog timing configuration: left unconnected or pulled up to VDD via 10 kΩ resistor enables factory-programmed 1600 ms timeout; connecting a capacitor to GND enables user-adjustable timing per tWD = 3.23 × CCWD(nF) + 0.381 ms (standard mode). Pin evaluation occurs once per power-up at VDD > VITN + VHYST.

Can TPS3851G33SDRBT monitor multiple voltage rails simultaneously?

No - TPS3851G33SDRBT monitors only the VDD supply rail it is powered from. It does not support multi-rail monitoring. For systems requiring supervision of multiple rails (e.g., 1.8 V, 3.3 V, 5.0 V), separate TPS3851 devices or a multi-channel supervisor like TPS386000 must be used.