Texas Instruments TPS3851G33EDRBR

Overview

TPS3851G33EDRBR from Texas Instruments is a precision voltage supervisor IC with integrated watchdog timer, designed for reliable power-rail monitoring and fault detection in microcontroller-based 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 - used in IP network cameras and string inverters for fail-safe boot and runtime supervision.

For engineers reviewing the TPS3851G33EDRBR datasheet, TPS3851G33EDRBR pinout, TPS3851G33EDRBR application, or TPS3851G33EDRBR equivalent, this page provides verified functional identity, validated VSON-8 pin mapping, confirmed watchdog timing modes (factory-programmed 1600 ms standard or user-adjustable via CWD capacitor), exact reset behavior under VDD transients, and real-world substitution guidance for industrial embedded designs requiring high-accuracy supervision.

Technical Context

The TPS3851G33EDRBR implements a precision bandgap-based comparator for undervoltage detection with factory-trimmed 0.8% VITN accuracy and 0.5% hysteresis, enabling stable operation in tight-tolerance systems. Its dual-output architecture separates RESET (system reset) and WDO (watchdog fault flag), allowing independent fault diagnosis without full system reboot.

Watchdog timing is configurable via CWD pin: unconnected or pulled up with 10 kΩ selects factory-programmed 1600 ms (typical) standard-mode timeout; capacitor-connected enables user-defined timing using 375 nA constant-current charge of CCWD to 1.21 V threshold. SET1 pin disables the watchdog entirely, and MR provides manual reset initiation with internal pullup.

Key Specifications

Pinout & Package

TPS3851G33EDRBR 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 automated optical inspection and offers low thermal resistance (RθJB = 25.8°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3851G33QDRBRQ1 and MAX6373KA33+T, the TPS3851G33EDRBR uniquely balances automotive-grade temperature range, 0.8% accuracy, dual-output fault signaling, and factory-programmed watchdog timing - making it optimal for industrial and medical systems where precision supervision and diagnostic capability are mandatory.

Availability

TPS3851G33EDRBR is available at Aetrix Electronics and suitable for IP network cameras, string inverters, wireless security cameras, and blood pressure monitors requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for TPS3851G33EDRBR 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 expertise in high-reliability supervisory circuits.

The TPS3851 product line was engineered specifically for mission-critical embedded systems needing simultaneous precision voltage monitoring and intelligent watchdog supervision - targeting industrial automation, medical devices, and network infrastructure.

FAQ

What is the undervoltage threshold voltage for TPS3851G33EDRBR?

The TPS3851G33EDRBR 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 means RESET asserts when VDD falls below 3.168 V and deasserts only after VDD rises above 3.168 V + hysteresis (≈3.184 V), ensuring stable operation in noisy environments. The 0.8% accuracy specification applies across –40°C to +125°C.

How does the watchdog timeout work on TPS3851G33EDRBR?

The TPS3851G33EDRBR offers two watchdog timeout modes: factory-programmed (1600 ms typical, selected when CWD is unconnected or pulled up to VDD with 10 kΩ) and user-adjustable (via capacitor on CWD pin). In standard mode, the watchdog asserts WDO after 1600 ms if no falling edge occurs on WDI. The timeout is disabled entirely when SET1 is grounded, and WDI must be driven to VDD or GND to avoid increased IDD.

Can TPS3851G33EDRBR monitor a 5.0 V rail?

Yes, the TPS3851G33EDRBR supports input voltages from 1.6 V to 6.5 V and can monitor 5.0 V rails - but its factory-set threshold is optimized for 3.3 V (VITN = 3.168 V). For 5.0 V supervision, TI recommends the TPS3851G50 variant (VITN = 4.8 V). Using TPS3851G33EDRBR on 5.0 V would result in undervoltage detection at ~3.17 V, which may not align with system requirements.

What is the function of the SET1 pin on TPS3851G33EDRBR?

The SET1 pin on TPS3851G33EDRBR controls watchdog enable/disable: grounding SET1 disables the watchdog timer entirely, causing WDI to be ignored and preventing unintended timeouts during development or debug. When SET1 is high, the watchdog operates normally. This pin can be changed dynamically, but a 150 µs setup time is required after enabling before WDI is recognized.

Does TPS3851G33EDRBR require external components for basic operation?

TPS3851G33EDRBR requires only three external components for full functionality: a 0.1 µF bypass capacitor on VDD, a pullup resistor (1–100 kΩ) on RESET, and a pullup resistor (1–100 kΩ) on WDO. No external timing components are needed when using factory-programmed watchdog mode. The MR pin may be left floating due to its internal pullup, and the thermal pad must be soldered to a PCB ground plane.