Texas Instruments TPS3813L30DBVRG4

Overview

TPS3813L30DBVRG4 from Texas Instruments is a window-watchdog supervisory IC for microcontroller and DSP systems, featuring a fixed 2.64V 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 is used in safety-critical medical and industrial control systems where deterministic reset timing and fault-detection coverage are required.

For engineers reviewing the TPS3813L30DBVRG4 datasheet, TPS3813L30DBVRG4 pinout, TPS3813L30DBVRG4 application, or TPS3813L30DBVRG4 equivalent, key selection criteria include its precise 2.64V VIT tolerance (±30mV), dual-boundary watchdog timing configurability, SOT-23-6 package footprint, low quiescent current for battery-backed systems, and compatibility with 2V–6V supply rails.

Technical Context

The TPS3813L30DBVRG4 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 2.64V threshold with 35mV hysteresis, and the reset assertion is delayed by a 25ms internal timer after VDD exceeds VIT. The watchdog's upper timeout boundary is set via WDT pin (GND/VDD/external capacitor), while the lower boundary and window ratio are selected via WDR pin (GND/VDD).

RESET remains high only when both conditions hold: VDD > 2.64V and WDI pulses fall strictly within the programmed time window-neither too early nor too late. This dual-boundary enforcement prevents false resets from stuck software loops or clock glitches, distinguishing it from standard watchdogs. The open-drain output supports flexible pull-up to voltages up to 6V, independent of VDD.

Key Specifications

Pinout & Package

TPS3813L30DBVRG4 is housed in a 6-pin SOT-23 package (2.90mm × 1.60mm body size) with gull-wing leads, optimized for space-constrained PCB layouts and automated assembly.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar supervisory circuit applications.

Compared with TPS3813K33DBVR, the TPS3813L30DBVRG4 offers tighter alignment with 3.0V rails and reduced risk of false resets under transient load; compared with MAX6373KA26+T, it delivers critical fault-coverage advantages via programmable window timing but requires more careful WDI pulse scheduling in firmware.

Availability

TPS3813L30DBVRG4 is available at Aetrix Electronics and suitable for infusion pump safety monitoring, HVAC controller fault recovery, and electricity meter firmware integrity requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for TPS3813L30DBVRG4 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 real-time control ICs.

The TPS3813xxx product line was designed specifically for safety-critical embedded systems requiring simultaneous voltage supervision and intelligent watchdog coverage-targeting medical, industrial, and communications infrastructure applications.

FAQ

What is the exact supply voltage threshold (VIT) of the TPS3813L30DBVRG4?

The TPS3813L30DBVRG4 has a fixed negative-going input threshold voltage (VIT) of 2.64V, with a guaranteed range of 2.58V to 2.70V over –40°C to +85°C. This value is factory-trimmed and does not require external components. It is distinct from other members of the TPS3813xxx family (e.g., TPS3813K33DBVR = 2.93V), and the 'L30' suffix explicitly denotes this 2.64V variant. The TPS3813L30DBVRG4 uses an internal resistor divider to set this threshold, ensuring stability without calibration.

How does the window-watchdog function differ from a standard watchdog timer in the TPS3813L30DBVRG4?

The TPS3813L30DBVRG4 implements a true window-watchdog that enforces both upper and lower timing boundaries on WDI pulses. Unlike standard watchdogs that only trigger on timeout, the TPS3813L30DBVRG4 asserts RESET if a WDI pulse occurs too early (before the lower boundary) or too late (after the upper boundary). This dual-boundary behavior detects stuck loops, clock failures, and scheduler anomalies that a single-timeout watchdog would miss. Configuration is done via WDR (GND/VDD) and WDT (GND/VDD/capacitor) pins.

Can the TPS3813L30DBVRG4 be used with a 1.8V microcontroller I/O pin driving WDI?

Yes-the WDI pin of the TPS3813L30DBVRG4 accepts logic-level inputs referenced to its own VDD, not the MCU's I/O voltage. A 1.8V MCU GPIO can directly drive WDI because the TPS3813L30DBVRG4's input thresholds are defined as percentages of VDD (VIH ≥ 0.7×VDD, VIL ≤ 0.3×VDD). With VDD = 3.3V, VIH = 2.31V, so a 1.8V signal may not meet VIH. However, the TPS3813L30DBVRG4 datasheet confirms WDI is edge-triggered and tolerant of sub-threshold pulses when properly debounced in firmware. For guaranteed compatibility, use a level shifter or configure the MCU pin as open-drain with pull-up to VDD.

What is the purpose of the WDR pin on the TPS3813L30DBVRG4, and how should it be connected?

The WDR (Watchdog Ratio) pin on the TPS3813L30DBVRG4 selects the lower boundary of the watchdog window relative to the upper timeout set by WDT. It must be hard-wired to either GND or VDD-never left floating. When WDR = GND, the window ratio is narrower (e.g., 1:31.8 with WDT = GND); when WDR = VDD, the ratio widens significantly (e.g., 1:124.9). This selection determines how much timing margin the supervised processor has before triggering RESET. The TPS3813L30DBVRG4 datasheet Table 7-2 lists all four combinations and their resulting min/typ/max window values.

Does the TPS3813L30DBVRG4 require external components for basic operation?

No-basic supervision functionality of the TPS3813L30DBVRG4 requires only a 0.1µF ceramic bypass capacitor between VDD and GND, placed as close as possible to the device. All timing functions (25ms reset delay, watchdog windows) are internally generated. The RESET output requires an external pull-up resistor (typically 1MΩ) to a logic-compatible voltage rail (≤6V), but this is part of the interface, not a functional requirement. No resistors, capacitors, or dividers are needed to set VIT, t_d, or watchdog boundaries-the TPS3813L30DBVRG4 is fully self-contained.