Texas Instruments TPS3850G33DRCT

Overview

TPS3850G33DRCT from Texas Instruments is a precision voltage supervisor IC with integrated programmable window watchdog timer, designed for system-level power integrity monitoring in high-reliability embedded applications. It delivers 0.8% threshold accuracy over –40°C to +125°C, supports 1.6 V–6.5 V supply range, features open-drain RESET and WDO outputs, and monitors rails from 0.9 V to 5.0 V with ±4% or ±7% fault windows - used in ultrasound scanners and active antenna systems.

For engineers reviewing the TPS3850G33DRCT datasheet, TPS3850G33DRCT pinout, TPS3850G33DRCT application, or TPS3850G33DRCT equivalent, key selection criteria include its factory-programmed vs capacitor-programmable reset/watchdog timing, dual-threshold window watchdog architecture, ±0.5% hysteresis, and 10-µA quiescent current - all validated for automotive-grade temperature operation.

Technical Context

The TPS3850G33DRCT implements a dual-comparator window supervision architecture on the SENSE pin, with independent overvoltage (VIT+(OV)) and undervoltage (VIT–(UV)) thresholds each achieving 0.8% accuracy across –40°C to +125°C. Its internal precision clock drives both the reset delay timer and the window watchdog state machine, enabling accurate timing without external crystals.

Watchdog functionality uses three inputs - WDI (watchdog input), CWD (capacitor or logic-selectable timeout), and SET0/SET1 (ratio configuration) - to define a time window (tWDL to tWDU) within which a valid edge must occur; failure asserts WDO only when RESET is deasserted, ensuring fault isolation between power and logic faults.

Key Specifications

Pinout & Package

TPS3850G33DRCT is housed in a 3.00-mm × 3.00-mm, 10-pin VSON package (DRC) with exposed thermal pad connected internally to GND - optimized for space-constrained PCB layouts and thermal dissipation in sealed enclosures.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3851G33DRCT, TPS3850G33DRCT trades dynamic watchdog control for simpler pin count and lower system-level routing complexity; versus MAX6373KA29+T, it provides 2× tighter threshold accuracy, full automotive temperature range, and true window-based fault discrimination - critical for real-time embedded safety.

Availability

TPS3850G33DRCT is available at Aetrix Electronics and suitable for ultrasound scanners, active antenna systems, robot servo drives, and HVAC controllers requiring stable component supply across extended temperature and long product lifecycles.

Supply support for TPS3850G33DRCT 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 high-reliability ICs.

The TPS3850 family was engineered for mission-critical power supervision in automotive ADAS, medical imaging, and 5G infrastructure - emphasizing precision timing, fault isolation, and extended temperature resilience.

FAQ

What is the function of the CRST pin on the TPS3850G33DRCT?

The CRST pin on the TPS3850G33DRCT configures the reset timeout period: connecting a capacitor to GND sets tRST from 703 µs to 3.22 s; a 10-kΩ pullup to VDD selects a factory-programmed 170–230 ms delay; leaving it unconnected chooses another factory default. The device evaluates CRST state each time SENSE re-enters its valid window, and TPS3850G33DRCT uses internal logic to distinguish between these configurations within 381 µs.

How does the TPS3850G33DRCT implement window watchdog functionality?

The TPS3850G33DRCT implements window watchdog functionality by defining two time boundaries - tWDL (lower) and tWDU (upper) - relative to the last WDI falling edge. A valid edge must occur strictly between them; early or late edges assert WDO. Boundaries are set via CWD capacitor value and SET0/SET1 logic states (e.g., SET0=0/SET1=1 yields 3:4 ratio). TPS3850G33DRCT only asserts WDO when RESET is high, ensuring watchdog faults are reported independently of power faults.

Can the TPS3850G33DRCT monitor multiple voltage rails simultaneously?

No, the TPS3850G33DRCT monitors only one rail via its single SENSE pin. However, it supports rails from 0.9 V to 5.0 V with selectable ±4% or ±7% fault windows, making it suitable for supervising critical individual supplies like VCORE or I/O. To monitor multiple rails, multiple TPS3850G33DRCT devices or a multi-channel supervisor (e.g., TPS386000) would be required - TPS3850G33DRCT is not multiplexed or cascaded for multi-rail operation.

What is the significance of the 0.5% hysteresis specification for the TPS3850G33DRCT?

The 0.5% hysteresis on both overvoltage and undervoltage thresholds prevents oscillatory reset behavior during slow or noisy supply transitions near the trip point. For example, with a 3.3-V nominal rail, hysteresis adds ~16.5 mV margin between turn-on and turn-off thresholds - ensuring TPS3850G33DRCT remains stable during brownout recovery or load-step transients without causing repeated MCU resets that could corrupt firmware execution.

Does the TPS3850G33DRCT require external passive components for basic operation?

Yes, the TPS3850G33DRCT requires a 0.1-µF bypass capacitor on VDD for noise immunity, and external pullup resistors (1–100 kΩ) on RESET and WDO outputs to establish valid logic-high levels. If programmable timing is used, capacitors on CRST and CWD pins are needed; if factory defaults are selected, those pins may be left unconnected or pulled up with 10-kΩ resistors - no inductors or active components are required for core supervision functionality.