Texas Instruments TPS3850G33DRCR

Overview

TPS3850G33DRCR from Texas Instruments is a precision voltage supervisor IC with integrated programmable window watchdog timer, designed for high-reliability microcontroller and SoC power-rail monitoring. 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/WDO outputs, and enables ±4% or ±7% fault windows on rails from 0.9 V to 5.0 V - used in ultrasound scanners and active antenna systems.

For engineers reviewing the TPS3850G33DRCR datasheet, TPS3850G33DRCR pinout, TPS3850G33DRCR application, or TPS3850G33DRCR equivalent, key selection criteria include factory-programmed vs capacitor-programmable reset/watchdog timing, SENSE pin glitch immunity (≥5 ps at 3% overdrive), hysteresis (0.5%), and VSON-10 thermal pad grounding requirements.

Technical Context

The TPS3850G33DRCR implements dual independent timing paths: one for RESET delay (programmable via CRST pin using capacitor or 10-kΩ pullup) and another for window watchdog boundaries (tWDL/tWDU), both derived from an internal precision clock. Its window comparator uses matched reference circuitry to achieve 0.8% total accuracy across temperature for both VIT+(OV) and VIT–(UV) thresholds.

Watchdog operation requires precise WDI edge timing within configurable tWDL–tWDU windows (e.g., 1.48–2.22 ms / 23.4–31.6 ms for 3/4 ratio); watchdog disable is achieved by setting SET0=1, SET1=0. The device operates with 10 µA typical supply current and supports 0.2%–0.8% hysteresis to prevent chatter near thresholds.

Key Specifications

Pinout & Package

TPS3850G33DRCR is housed in a 3.00-mm × 3.00-mm, 10-pin VSON package (DRC) with exposed thermal pad internally connected to GND. The package supports high-density PCB layouts and provides low thermal resistance (RθJB = 26.1°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3850G33DRCR, TPS3851G33DRCR adds PFI/MR capability at the cost of two extra pins and slightly higher complexity, while MAX6373KA29+T sacrifices programmability and accuracy for footprint and cost reduction in non-watchdog applications.

Availability

TPS3850G33DRCR is available at Aetrix Electronics and suitable for ultrasound scanners, storage area networks, active antenna systems, and robot servo drives requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for TPS3850G33DRCR 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 precision analog ICs and power management solutions.

The TPS3850 product line delivers high-accuracy voltage supervision with integrated window watchdog timers for mission-critical applications in medical imaging, communications infrastructure, and industrial automation where deterministic fault detection is essential.

FAQ

What is the operating temperature range for the TPS3850G33DRCR?

The TPS3850G33DRCR operates across a junction temperature range of –40°C to +125°C, validated per its electrical characteristics table and thermal metrics (RθJB = 26.1°C/W). This range supports deployment in harsh environments such as outdoor 5G base stations and industrial motor drives, where ambient temperatures exceed 85°C and board-level heating must be managed via the exposed thermal pad.

How does the TPS3850G33DRCR implement window watchdog functionality?

The TPS3850G33DRCR implements window watchdog functionality by requiring a falling edge on the WDI pin to occur strictly between two time boundaries - tWDL (lower) and tWDU (upper) - which are set via CWD capacitor value and SET0/SET1 logic states. If no edge arrives within this window, WDO asserts low for the programmed RESET delay duration. This detects both stuck-at-high and slow-clock faults unlike standard timeout watchdogs.

Can the TPS3850G33DRCR monitor multiple voltage rails simultaneously?

No, the TPS3850G33DRCR monitors only one rail via its single SENSE pin. To supervise multiple rails (e.g., 1.2-V core and 3.3-V I/O), separate TPS3850G33DRCR devices or a multi-rail supervisor like the TPS386000 must be used. Each TPS3850G33DRCR instance requires its own SENSE connection, CRST/CWD timing components, and RESET/WDO pullup resistors.

What are the valid configurations for disabling the watchdog timer in the TPS3850G33DRCR?

The TPS3850G33DRCR watchdog can be disabled by setting SET0 = high (≥0.8 × VDD) and SET1 = low (≤0.25 V), regardless of CWD pin state. When disabled, the WDI input is ignored, and WDO remains in high-impedance state unless asserted by RESET. This configuration is explicitly defined in Table 6.6 and Section 7.3.4 of the datasheet.

What is the minimum recommended pullup resistor value for the RESET and WDO outputs of the TPS3850G33DRCR?

The minimum recommended pullup resistor value for RESET and WDO is 1 kΩ, specified in Section 6.3 Recommended Operating Conditions. Using <1 kΩ risks exceeding the 20-mA absolute maximum sink current rating when the output is asserted low; 10-kΩ is commonly used to balance speed, power, and noise immunity while staying within VOL ≤0.4 V at 3 mA sink current.