Texas Instruments TPS3851G50EDRBT

Overview

TPS3851G50EDRBT from Texas Instruments is a precision voltage supervisor IC with integrated watchdog timer, designed for reliable power monitoring and fault detection in microcontroller-based systems. It features 4.8 V undervoltage threshold (VITN), 0.8% accuracy over –40°C to +125°C, 200 ms reset timeout (tRST), open-drain RESET/WDO outputs, and user-programmable watchdog via CWD pin - deployed in WLAN access points and IP network cameras.

For engineers reviewing the TPS3851G50EDRBT datasheet, TPS3851G50EDRBT pinout, TPS3851G50EDRBT application, or TPS3851G50EDRBT equivalent, this page delivers verified specifications, validated pin functions, confirmed thermal and timing behavior, and real-world implementation context for industrial and embedded power supervision design.

Technical Context

The TPS3851G50EDRBT implements a high-accuracy comparator-based undervoltage detection circuit with 0.5% hysteresis and factory-trimmed 4.8 V threshold, enabling stable reset assertion before microcontroller brownout. Its dual-mode watchdog uses either internal 1600 ms standard timing (CWD unconnected, SET1 = 1) or external capacitor programming (CCWD = 0.1–1000 nF), with independent WDO output for non-reset fault signaling.

RESET activation follows precise propagation delay (tRST-DEL ≤ 35 µs) and fixed 200 ms deassertion delay (tRST = 170–230 ms), while MR input supports manual reset with 200 ns response. All logic inputs (MR, SET1, WDI) comply with 0.25 V/0.8 V thresholds at VDD = 1.6–6.5 V, and the device operates with only 10 µA quiescent current.

Key Specifications

Pinout & Package

TPS3851G50EDRBT 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 per JEDEC J-STD-020 and achieves RθJB = 25.8°C/W for efficient heat dissipation in high-density designs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3851G50EDRBT, the G18 variant serves lower-voltage rails but shares identical watchdog architecture and timing accuracy, while the MAX6369 offers smaller footprint at the cost of diagnostic capability and threshold flexibility.

Availability

TPS3851G50EDRBT is available at Aetrix Electronics and suitable for WLAN access points, IP network cameras, and string inverter control boards requiring stable component supply, long-term manufacturability, and automotive-grade temperature resilience.

Supply support for TPS3851G50EDRBT 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 and embedded processing technologies, with decades of expertise in power management and system supervision ICs.

The TPS3851 product line delivers high-accuracy voltage supervisors with integrated watchdog timers for mission-critical embedded systems where power integrity and software reliability are non-negotiable - targeting industrial automation, medical devices, and network infrastructure.

FAQ

What is the exact undervoltage threshold voltage of the TPS3851G50EDRBT?

The TPS3851G50EDRBT has a nominal undervoltage threshold (VITN) of 4.8 V, with guaranteed accuracy of ±0.8% across –40°C to +125°C. This value is factory-trimmed and confirmed in TI's SBVS300B datasheet Figure 5-9 and Table 5.5, making it suitable for precise supervision of 5 V rails without additional margining.

Does the TPS3851G50EDRBT require an external capacitor for basic watchdog operation?

No, the TPS3851G50EDRBT does not require an external capacitor for basic watchdog operation. When CWD is left unconnected and SET1 is high, it defaults to factory-programmed 1600 ms watchdog timeout. An external capacitor is only needed if user-adjustable timing (e.g., 0.7 ms to 77 s) is required per Equation 1 and Equation 2 in the datasheet.

How does the TPS3851G50EDRBT handle reset timing during power-up?

The TPS3851G50EDRBT enforces a 300 µs minimum VDD stabilization period before RESET becomes valid. Below VPOR (0.8 V), RESET state is undefined. Between VPOR and VITN (4.8 V), RESET remains asserted. Only after VDD exceeds VITN + VHYST (4.824 V) does the 200 ms tRST timer begin, ensuring clean MCU initialization.

Can the TPS3851G50EDRBT's WDO output be used independently of the RESET signal?

Yes, the TPS3851G50EDRBT's WDO output operates independently of RESET: WDO asserts low only when RESET is high and a watchdog timeout occurs. If RESET is low (e.g., due to undervoltage), WDO enters high-impedance state - enabling separate fault signaling without triggering system reset.

What is the recommended pullup resistor value for the RESET and WDO pins of the TPS3851G50EDRBT?

Texas Instruments specifies a 1 kΩ to 100 kΩ pullup resistor for both RESET and WDO pins of the TPS3851G50EDRBT. A 10 kΩ resistor is commonly used to balance speed (lower R) and power (higher R), ensuring VOL ≤ 0.4 V at 3 mA sink while maintaining compatibility with 3.3 V or 5 V logic interfaces.