Texas Instruments TPS3813K33DBVT

Overview

TPS3813K33DBVT from Texas Instruments is a window-watchdog supervisory IC for microcontroller and DSP systems, featuring a fixed 2.93V supply voltage threshold (VIT), 25ms power-on reset delay, 9µA typical supply current, open-drain RESET output, and programmable watchdog window ratio via WDR/WDT pins. It operates across –40°C to +85°C and targets safety-critical embedded control.

For engineers reviewing the TPS3813K33DBVT datasheet, TPS3813K33DBVT pinout, TPS3813K33DBVT application, or TPS3813K33DBVT equivalent, key selection considerations include its precise 2.93V VIT tolerance (±70mV), dual-boundary watchdog timing configurability, SOT-23-6 package footprint, and compatibility with 2V–6V supply rails in industrial and medical systems.

Technical Context

The TPS3813K33DBVT integrates a precision voltage supervisor and a user-programmable window-watchdog timer in a single 6-pin SOT-23 device. Its internal bandgap reference sets a fixed 2.93V VIT with 40mV hysteresis, and it asserts RESET when VDD falls below VIT or when WDI pulses miss the configured time window.

Watchdog timing is defined by two independent inputs: WDT selects upper timeout (0.25s/2.5s or capacitor-programmable up to ~63nF), while WDR selects lower boundary ratio (1:31.8 to 1:127.7). The device requires no external components for basic operation and supports open-drain RESET interfacing up to 6V.

Key Specifications

Pinout & Package

TPS3813K33DBVT is housed in a 6-pin SOT-23 package (2.90mm × 1.60mm body size) with standard JEDEC MO-178AC outline and thermal pad omitted.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3813L30DBVT and TPS3813I50DBVT, the TPS3813K33DBVT provides optimal voltage threshold alignment for modern 3.3V microcontrollers-reducing risk of spurious reset during nominal rail operation while maintaining sufficient headroom for brownout detection.

Availability

TPS3813K33DBVT is available at Aetrix Electronics and suitable for infusion pump control, industrial HVAC controllers, electricity metering units, and safety-critical AAS subsystems requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for TPS3813K33DBVT 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 delivering analog and embedded processing solutions, with over 90 years of innovation in power management, signal chain, and real-time control technologies.

The TPS3813xxx family was designed specifically for high-reliability processor supervision in safety-critical applications-integrating precision voltage monitoring and programmable window-watchdog functionality into a minimal 6-pin SOT-23 footprint.

FAQ

What is the exact supply voltage threshold (VIT) for TPS3813K33DBVT?

The TPS3813K33DBVT has a fixed negative-going input threshold voltage (VIT) of 2.93V, with a guaranteed range of 2.87V to 3.00V over –40°C to +85°C. This value is laser-trimmed during manufacturing and does not require external configuration. The 40mV hysteresis ensures noise immunity during voltage recovery transitions. All specifications for TPS3813K33DBVT are validated per TI's SLVS331J datasheet revision August 2024.

How does the window-watchdog function work on TPS3813K33DBVT?

The TPS3813K33DBVT implements a two-boundary watchdog: the upper timeout is set via WDT (GND = 0.25s, VDD = 2.5s, or capacitor), and the lower boundary ratio is set via WDR (GND = narrow, VDD = wide). The supervised processor must assert WDI within this window-missing either boundary triggers RESET. This prevents both software hangs and premature timeouts due to jitter. The TPS3813K33DBVT's architecture eliminates reliance on single-point watchdog triggers.

Can TPS3813K33DBVT be used with a 5V microcontroller RESET input?

Yes. The TPS3813K33DBVT features an open-drain RESET output rated for up to 6V, allowing direct connection to 5V microcontroller RESET pins using a 5V pull-up resistor. The device itself operates from 2V–6V VDD, so it can supervise a 3.3V rail while driving a 5V RESET line-no level shifter required. This interoperability is explicitly supported in TPS3813K33DBVT's electrical characteristics table (Section 6.5).

What is the minimum recommended bypass capacitor for TPS3813K33DBVT VDD?

A 0.1µF ceramic capacitor is the minimum recommended bypass capacitor for the VDD pin of TPS3813K33DBVT, placed as close as possible to the pin. TI specifies this value to ensure stable internal reference operation and glitch immunity during fast transients. Larger values (up to 1µF) may be used in noisy environments, but the 0.1µF part is mandatory for proper power-on reset behavior and threshold accuracy per Section 7.3.1.1 of the TPS3813K33DBVT datasheet.

Does TPS3813K33DBVT require external components for basic supervision functionality?

No. TPS3813K33DBVT requires no external components for core voltage supervision and fixed watchdog operation. Only a 0.1µF VDD bypass capacitor is mandatory. WDT and WDR pins can be hard-wired to GND or VDD to select preset timing modes-eliminating need for resistors or capacitors in most implementations. External capacitors on WDT are optional only when non-standard timeout values (between 0.25s and 2.5s) are required for the TPS3813K33DBVT.