Texas Instruments TPS3851G30EDRBT

Overview

TPS3851G30EDRBT from Texas Instruments is a precision voltage supervisor IC with integrated watchdog timer, designed for reliable power-up sequencing and fault detection in microcontroller-based systems. It delivers 0.8% undervoltage threshold accuracy (–40°C to +125°C), 200 ms reset timeout (±15%), and user-programmable watchdog timeout via external capacitor or factory-set values. Its dual open-drain outputs (RESET and WDO) support independent fault signaling in industrial IoT gateways and smart metering applications.

For engineers reviewing the TPS3851G30EDRBT datasheet, TPS3851G30EDRBT pinout, TPS3851G30EDRBT application, or TPS3851G30EDRBT equivalent, key selection considerations include its 1.6V–6.5V supply range, 10 µA quiescent current, 0.5% hysteresis, 8-pin VSON package, and factory-programmed watchdog timing options-critical for low-power, high-reliability embedded supervision.

Technical Context

The TPS3851G30EDRBT implements a precision comparator-based undervoltage detection circuit with tightly controlled 0.8% VITN accuracy across temperature, paired with a state-machine-driven watchdog timer that supports both standard (170–230 ms) and extended (1360–1840 ms) factory-programmed timeouts. Its dual-output architecture separates system reset (RESET) from fault diagnostics (WDO), enabling selective recovery without full reboot.

Functional modes are determined by VDD level relative to VPOR (0.8 V), VITN (3.0 V nominal), and VITN + VHYST (3.015 V), with MR input providing manual reset initiation and SET1 enabling dynamic watchdog enable/disable. The CWD pin's 375 nA constant-current source enables accurate RC-based timeout programming, while internal pullups and glitch-immune logic ensure robust operation in noisy environments.

Key Specifications

Pinout & Package

TPS3851G30EDRBT is housed in a thermally enhanced 3.00 mm × 3.00 mm, 8-pin VSON (DRB) package with exposed thermal pad connected internally to GND. The package supports high-density PCB layouts and efficient heat dissipation in compact industrial modules.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3851G30EDRBT, the TPS3851G33EDRBT offers identical functionality at a higher threshold for 3.3 V systems, while the MAX6373KA30+T provides basic supervision in larger SOIC packaging but omits diagnostic WDO and programmable timing-making it suitable only for simpler, lower-cost implementations.

Availability

TPS3851G30EDRBT is available at Aetrix Electronics and suitable for industrial IoT gateways, smart metering systems, and wireless security camera designs requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for TPS3851G30EDRBT 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 industrial and automotive ICs.

The TPS3851G30EDRBT belongs to TI's precision voltage supervisor product line, engineered specifically for mission-critical embedded systems demanding sub-1% threshold accuracy, dual-fault signaling, and extended temperature operation.

FAQ

What is the exact undervoltage threshold voltage for TPS3851G30EDRBT?

The TPS3851G30EDRBT has a nominal undervoltage threshold (VITN) of 3.0 V with ±0.8% accuracy over –40°C to +125°C. This means the actual trip point falls between 2.976 V and 3.024 V under specified conditions, making it suitable for precise supervision of 3.3 V rails with tight tolerance margins. The device also provides 0.5% hysteresis (15 mV) to prevent oscillation during supply recovery.

How does the watchdog timeout work on TPS3851G30EDRBT?

The TPS3851G30EDRBT supports two watchdog timeout configurations: factory-programmed (170–230 ms standard or 1360–1840 ms extended) selected via CWD pin connection (10 kΩ pullup or open), or user-programmable using an external capacitor (0.1–1000 nF) on CWD. The 375 nA internal current source charges the capacitor to 1.21 V, determining timeout per tWD = 3.23 × CCWD + 0.381 ms (standard mode).

Can TPS3851G30EDRBT monitor multiple voltage rails?

No-the TPS3851G30EDRBT monitors only the VDD supply rail applied to its Pin 1. It does not support multi-rail supervision or external voltage divider inputs. For systems requiring supervision of multiple rails (e.g., 1.2 V, 1.8 V, 3.3 V), separate TPS3851 devices or a multi-channel supervisor like TPS386000 must be used. Its design focuses on high-accuracy single-rail monitoring with integrated watchdog functionality.

What is the function of the SET1 pin on TPS3851G30EDRBT?

The SET1 pin (Pin 5) on TPS3851G30EDRBT enables or disables the watchdog timer function. When SET1 is grounded, the watchdog is disabled and WDI input is ignored-useful during firmware development to avoid unintended timeouts. When SET1 is pulled high, the watchdog operates normally. The pin can be toggled dynamically, with a 150 µs setup time required after enabling before WDI becomes active.

Is TPS3851G30EDRBT compatible with 1.8 V I/O systems?

Yes-TPS3851G30EDRBT's open-drain RESET and WDO outputs are compatible with 1.8 V logic domains when pulled up to a 1.8 V rail using a 1–100 kΩ resistor. Its input pins (MR, SET1, WDI) accept 0.25 V low and 0.8 × VDD high thresholds, supporting direct interfacing with 1.8 V GPIOs. However, VDD must remain within 1.6–6.5 V, so 1.8 V systems require VDD ≥ 1.8 V for proper operation.