Texas Instruments TPS3851G30EDRBR

Overview

TPS3851G30EDRBR from Texas Instruments is a precision voltage supervisor with integrated watchdog timer, designed for microcontroller and SoC power-rail monitoring in industrial and embedded systems. It delivers 0.8% undervoltage threshold accuracy (–40°C to +125°C), 200 ms reset timeout (±15%), 10 µA quiescent current, and supports 1.8V–5.0V supply rails with 0.5% hysteresis. Its dual open-drain outputs (RESET and WDO) enable independent fault signaling without full system reset.

For engineers reviewing the TPS3851G30EDRBR datasheet, TPS3851G30EDRBR pinout, TPS3851G30EDRBR application, or TPS3851G30EDRBR equivalent, this device serves as a high-accuracy supervisory solution where tight tolerance rail monitoring, programmable watchdog timing, and thermal robustness (–40°C to +125°C) are critical - especially in IP cameras, string inverters, and medical instrumentation.

Technical Context

The TPS3851G30EDRBR implements a precision comparator-based undervoltage detection circuit with factory-trimmed reference and 0.5% hysteresis, ensuring stable RESET assertion/deassertion across temperature and noise. Its watchdog logic uses either internal state-machine-controlled factory-programmed delays (1600 ms typical) or external capacitor-programmable timing (via CWD pin with 375 nA constant-current source).

It features independent control paths: MR initiates reset regardless of VDD status; SET1 disables watchdog functionality entirely; WDI accepts falling-edge-triggered pulses; and WDO asserts only when RESET is high - enabling fault isolation without cascading resets. All digital inputs (MR, SET1, WDI) support 0.25 V/0.8 V logic thresholds over full temperature range.

Key Specifications

Pinout & Package

TPS3851G30EDRBR is housed in a thermally enhanced 3.00 mm × 3.00 mm, 8-pin VSON package (DRB) with exposed thermal pad connected internally to GND. The package supports reflow soldering and provides low thermal resistance (R_θJB = 25.8°C/W) for sustained operation in compact, sealed enclosures.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3851G18EDRBR and TPS3851G50EDRBR, the TPS3851G30EDRBR provides optimal threshold alignment for 3.3 V systems - avoiding external resistor networks while maintaining identical watchdog functionality, thermal performance, and layout compatibility.

Availability

TPS3851G30EDRBR is available at Aetrix Electronics and suitable for IP network cameras, string inverter control units, blood pressure monitors, and electricity meters requiring stable component supply, long-lifecycle assurance, and guaranteed traceability.

Supply support for TPS3851G30EDRBR 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 ICs, with decades of expertise in high-reliability industrial and automotive solutions.

The TPS3851 product line delivers precision voltage supervision with integrated watchdog timers for mission-critical embedded systems - engineered to meet stringent accuracy, thermal, and long-term stability requirements in smart energy, medical, and infrastructure applications.

FAQ

What is the undervoltage threshold voltage of the TPS3851G30EDRBR?

The TPS3851G30EDRBR has a fixed undervoltage threshold (V_ITN) of 3.0 V, optimized for monitoring standard 3.3 V supply rails. This value is factory-trimmed to ±0.8% accuracy across –40°C to +125°C, ensuring precise reset activation before the microcontroller's minimum operating voltage is breached. The device also provides 0.5% hysteresis to prevent oscillation during marginal supply conditions.

How does the watchdog timeout work on the TPS3851G30EDRBR?

The TPS3851G30EDRBR offers two watchdog timeout modes: factory-programmed (1600 ms typical) when CWD is unconnected or pulled up to VDD via 10 kΩ, and user-adjustable via external capacitor on CWD (t_WD = 3.23×C_CWD + 0.381 ms). The watchdog is enabled only when SET1 is high; it monitors falling edges on WDI and asserts WDO if no pulse occurs before timeout - but only when RESET is high.

Can the TPS3851G30EDRBR monitor multiple voltage rails?

No - the TPS3851G30EDRBR monitors only the VDD supply rail directly. It does not support multi-rail supervision or external voltage dividers for higher-voltage rails. For 5 V rail monitoring, use TPS3851G50EDRBR; for 1.8 V, use TPS3851G18EDRBR. Each variant shares identical watchdog, reset timing, and package characteristics but differs solely in factory-set V_ITN.

What is the purpose of the SET1 pin on the TPS3851G30EDRBR?

The SET1 pin on the TPS3851G30EDRBR controls watchdog enable/disable functionality: grounding SET1 disables the watchdog timer entirely, causing WDI to be ignored and preventing WDO assertion. When disabled, WDI must be driven to a defined logic level (VDD or GND) to avoid increased supply current. SET1 can be toggled dynamically, with a 150 µs setup time required after enabling.

Does the TPS3851G30EDRBR require an external pullup resistor on RESET and WDO?

Yes - both RESET and WDO are open-drain outputs and require external pullup resistors (1 kΩ to 100 kΩ) to the appropriate interface voltage rail (e.g., 3.3 V for MCU I/O). The pullup value affects VOL, rise time, and noise immunity; TI recommends 10 kΩ as a balanced default. Pullup voltage must match the logic level of the connected device to ensure valid signal interpretation.