Texas Instruments TPS3852H33DRBT

Overview

TPS3852H33DRBT from Texas Instruments is a precision voltage supervisor IC with integrated window watchdog timer, designed for system-level power monitoring and fault detection in microcontroller-based systems. It delivers 0.8% undervoltage threshold accuracy over –40°C to +125°C, ±15% factory-programmed watchdog timing accuracy, 10 µA typical supply current, and operates across 1.6 V to 6.5 V VDD. It is used in safety-critical industrial control units where reliable reset assertion and precise fault-window detection are required.

For engineers reviewing the TPS3852H33DRBT datasheet, TPS3852H33DRBT pinout, TPS3852H33DRBT application, or TPS3852H33DRBT equivalent, key selection considerations include its 3.3-V nominal monitored rail support, programmable CWD timing interface, open-drain RESET/WDO outputs, manual reset (MR) input, and SET1 watchdog enable/disable control - all in an 8-pin VSON package.

Technical Context

The TPS3852H33DRBT implements a dual-path supervision architecture: one path monitors VDD against a precision 3.3-V undervoltage threshold (VITN = 3.168 V) with 0.5% hysteresis, while the second path executes a window watchdog function using either factory-programmed delays (e.g., tWDL = 800 ms typ, tWDU = 1600 ms typ) or user-adjustable capacitor-based timing. Its internal state machine evaluates CWD pin configuration at power-up to select timing mode.

RESET assertion is triggered when VDD falls below VITN and held low for tRST = 200 ms (typ), while WDO asserts independently only when WDI pulses fall outside the defined time window - enabling fault classification without full system reset. MR and SET1 inputs provide external control of reset initiation and watchdog enable/disable, respectively, with internal pull-ups eliminating need for external biasing.

Key Specifications

Pinout & Package

TPS3852H33DRBT is housed in a 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 thermal dissipation via soldered thermal pad to ground plane.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3852H33DRBT, TPS3851H33DRBT removes watchdog intelligence for simpler reset-only use, while MAX6373KA33+T trades accuracy, programmability, and package size for lower unit cost - making each alternative viable only when those specific trade-offs align with design constraints.

Availability

TPS3852H33DRBT is available at Aetrix Electronics and suitable for industrial control systems, patient monitoring equipment, telematics control units, and FPGA-based embedded platforms requiring stable component supply with guaranteed long-term manufacturability.

Supply support for TPS3852H33DRBT 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 decades of leadership in power management and precision analog ICs.

The TPS385x family was developed to address increasing demand for high-accuracy, low-power supervision in safety-critical industrial and medical systems - combining precision voltage monitoring with intelligent window watchdog functionality in compact packages.

FAQ

What is the exact undervoltage threshold voltage (VITN) for TPS3852H33DRBT?

The TPS3852H33DRBT has a nominal undervoltage threshold of 3.168 V, corresponding to a 3.3-V rail with –4% tolerance. This value is factory-trimmed to ±0.8% accuracy over –40°C to +125°C, ensuring consistent reset behavior across temperature and process variation. The device achieves this precision using laser-trimmed internal resistors and a bandgap reference, not external components.

How does the CWD pin configure watchdog timing on TPS3852H33DRBT?

The CWD pin on TPS3852H33DRBT selects watchdog timing mode at power-up: left unconnected or pulled to VDD via 10-kΩ resistor enables factory-programmed tWDL/tWDU (e.g., 800 ms / 1600 ms); connection to ground via capacitor enables user-adjustable timing per tWDU(typ) = 77.4 × CCWD(µF) + 0.055 s. The internal state machine evaluates CWD within 381 µs after VDD exceeds VPOR.

Can TPS3852H33DRBT monitor a 3.3-V rail while powered from a different supply voltage?

Yes - TPS3852H33DRBT monitors its own VDD pin, so it directly supervises the rail it is powered from. To supervise a separate 3.3-V rail, connect that rail to VDD. Its 1.6 V to 6.5 V VDD range accommodates direct connection to 3.3-V supplies. For monitoring auxiliary rails (e.g., 1.8-V or 5-V), use dedicated variants like TPS3852G18 or TPS3852G50 - the 'H33' suffix denotes 3.3-V nominal threshold.

What happens to WDO when RESET is asserted on TPS3852H33DRBT?

When RESET is asserted (low), WDO enters a high-impedance state regardless of WDI activity - this is defined in the functional modes table. WDO only actively drives low when RESET is high *and* a WDI pulse violates the tWDL–tWDU window. This separation prevents conflicting signals during power faults and enables independent fault reporting paths.

Is the thermal pad of TPS3852H33DRBT electrically connected, and how must it be handled?

Yes - the thermal pad of TPS3852H33DRBT is internally connected to GND. It must be soldered to a large-area PCB ground plane to ensure proper thermal performance (RθJB = 25.8°C/W) and electrical stability. Leaving the pad unconnected degrades thermal resistance by >2× and may cause junction temperature exceedance under sustained load, violating recommended operating conditions.