Texas Instruments TPS3850G18DRCR

Overview

TPS3850G18DRCR from Texas Instruments is a precision voltage supervisor IC with integrated programmable window watchdog timer, designed for high-reliability power-rail monitoring in microcontroller and SoC systems. 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 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 TPS3850G18DRCR datasheet, TPS3850G18DRCR pinout, TPS3850G18DRCR application, or TPS3850G18DRCR equivalent, key selection criteria include its factory-programmed vs capacitor-programmable reset/watchdog timing, dual-threshold hysteresis (0.5%), SENSE pin glitch immunity, and compatibility with tight-tolerance 1.8 V core rails in industrial and medical embedded systems.

Technical Context

The TPS3850G18DRCR implements a dual-comparator window architecture on the SENSE pin with independent overvoltage (VIT+(OV)) and undervoltage (VIT–(UV)) thresholds, each achieving 0.8% accuracy across temperature. Its internal precision clock drives both the RESET delay timer and the window watchdog state machine, enabling accurate timing without external crystals.

Watchdog operation uses a configurable window ratio (1/8, 3/4, or 1/2) selected via SET0/SET1 logic inputs, with upper/lower boundaries programmable via CWD capacitor or factory settings. The CRST pin similarly configures RESET delay using capacitor or 10-kΩ pullup, while WDI edge detection enforces strict timing compliance between tWDL(max) and tWDU(min).

Key Specifications

Pinout & Package

TPS3850G18DRCR 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 reflow soldering and provides low thermal resistance (RθJA = 52.3°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3850G18DRCR, TPS3851G18DRCR trades SENSE flexibility for tighter reference stability on 1.8 V rails, while MAX6373KA18+T omits watchdog entirely and sacrifices accuracy and temperature range - making TPS3850G18DRCR the sole option supporting programmable window supervision across multi-voltage systems.

Availability

TPS3850G18DRCR is available at Aetrix Electronics and suitable for ultrasound scanner power management, active antenna system (AAS) monitoring, robot servo drive control, infusion pump safety supervision, and HVAC controller reliability assurance requiring stable component supply across extended temperature and long product lifecycles.

Supply support for TPS3850G18DRCR 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 medical IC design.

The TPS3850 family was developed to address growing demand for precision, multi-function power supervisors in safety-critical embedded systems - combining accurate voltage monitoring, programmable watchdog timing, and robust thermal performance in miniature packages.

FAQ

What is the primary function of the TPS3850G18DRCR in a microcontroller system?

The TPS3850G18DRCR serves as a dual-role precision supervisor: it monitors the SENSE pin voltage against tightly specified overvoltage and undervoltage thresholds (±0.8% accuracy), and independently manages a window watchdog timer that validates firmware responsiveness. In a microcontroller system, this ensures both correct power-rail conditions and software execution integrity - preventing silent failures due to hung code or marginal supply levels. The TPS3850G18DRCR achieves this with minimal quiescent current (10 µA) and no external timing components required.

How does the TPS3850G18DRCR implement window watchdog functionality?

The TPS3850G18DRCR implements window watchdog functionality by requiring a falling edge on the WDI pin to occur strictly between two time boundaries - the lower watchdog limit (tWDL) and upper watchdog limit (tWDU). These boundaries are determined by CWD pin configuration (capacitor or resistor) and SET0/SET1 logic states, enabling ratios of 1/8, 3/4, or 1/2. If WDI is not toggled within this window, WDO asserts low. Critically, WDO only activates when RESET is high, preserving independent fault signaling. This behavior is fully documented in Section 6.6 and Figure 6-2 of the TPS3850G18DRCR datasheet.

Can the TPS3850G18DRCR supervise voltage rails other than 1.8 V?

Yes, the TPS3850G18DRCR can supervise any rail from 0.9 V to 5.0 V via its SENSE pin - the "G18" suffix denotes factory-trimmed 1.8 V thresholds, but the device's architecture supports user-defined thresholds through external resistor dividers. Its ±4% and ±7% fault windows, 0.5% hysteresis, and 0.8% accuracy apply across the full 0.9–5.0 V range. For example, connecting a 3.3 V rail directly to SENSE enables supervision with VIT+(OV) ≈ 3.43 V and VIT–(UV) ≈ 3.17 V (±4% window), verified in Electrical Characteristics Table 6.5.

What are the valid configurations for the CRST pin on the TPS3850G18DRCR?

The CRST pin on the TPS3850G18DRCR supports three validated configurations: (1) left unconnected (NC) for factory-programmed 170–230 ms reset delay, (2) pulled up to VDD via a 10-kΩ resistor for 8.5–11.5 ms delay, or (3) connected to ground via an external capacitor (0.1–1000 nF) for adjustable delay from 703 µs to 3.22 s. The device internally evaluates CRST every time SENSE re-enters the valid window, with a 381 µs evaluation period (tINIT). All configurations are explicitly defined in Table 5-1 and Section 7.3.1 of the TPS3850G18DRCR datasheet.

Does the TPS3850G18DRCR require external passive components for basic operation?

The TPS3850G18DRCR requires only two external components for basic operation: a 0.1-µF bypass capacitor on VDD (per Section 5 and layout guidelines), and pullup resistors (1–100 kΩ) on RESET and WDO open-drain outputs. No external timing capacitors or resistors are mandatory - factory-programmed reset and watchdog delays are functional out-of-box. Capacitors on CRST and CWD are optional for user-programmable timing. SENSE connects directly to the monitored rail; no divider is needed for 1.8 V, though one may be added for other voltages.