Texas Instruments TPS3813J25DBVT

Overview

TPS3813J25DBVT from Texas Instruments is a window-watchdog supervisory IC for microcontroller and DSP systems, featuring a fixed 2.25V supply voltage threshold (VIT), 25ms power-on reset delay, 9µA typical supply current, open-drain RESET output, and operation from –40°C to +85°C. It monitors VDD and enforces strict timing compliance via programmable watchdog window boundaries in safety-critical embedded control.

For engineers reviewing the TPS3813J25DBVT datasheet, TPS3813J25DBVT pinout, TPS3813J25DBVT application, or TPS3813J25DBVT equivalent, key selection considerations include its 2.25V precision voltage monitor, SOT-23-6 package compatibility, window-watchdog configurability via WDT/WDR pins, and suitability for fail-safe reset supervision in medical and industrial systems.

Technical Context

The TPS3813J25DBVT integrates a precision voltage supervisor with a user-programmable window-watchdog timer. Its internal comparator uses a bandgap reference to detect VDD crossing 2.25V ±0.05V, while hysteresis (30mV) prevents false resets during supply transients. The watchdog's upper timeout boundary is set by WDT pin state (GND/VDD/external capacitor), and lower boundary by WDR pin (GND/VDD), establishing a fixed ratio window (e.g., 1:31.8 to 1:127.7).

RESET assertion occurs when VDD drops below 2.25V or WDI pulses fall outside the configured window. The device operates from 2V–6V supply, draws only 9µA at 2V, and features glitch immunity (3µs minimum pulse width at VIT) and open-drain output capable of sinking 5mA with VOL ≤0.2V at 500µA load.

Key Specifications

Pinout & Package

TPS3813J25DBVT is housed in a 6-pin SOT-23 package with 2.90mm × 1.60mm body size and standard lead pitch. Pin functions are validated per TI SLVS331J datasheet Figure 5-1 and Table 5-1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3813L30DBVT, the TPS3813J25DBVT offers tighter alignment with 2.5V nominal supplies and lower threshold hysteresis (30mV vs. 35mV), improving noise margin in noisy industrial environments; versus TPS3803-01DBVT, it adds critical window-watchdog capability for detecting firmware timing anomalies beyond simple timeout failure.

Availability

TPS3813J25DBVT is available at Aetrix Electronics and suitable for infusion pumps, electricity meters, HVAC controllers, and active antenna systems requiring stable component supply, long-term lifecycle support, and guaranteed traceability.

Supply support for TPS3813J25DBVT 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 experience in high-reliability industrial and medical IC design.

The TPS3813xxx product line was developed specifically for safety-critical embedded systems requiring simultaneous voltage monitoring and intelligent watchdog supervision-enabling robust fault detection in medical, energy, and communications infrastructure.

FAQ

What is the exact supply voltage threshold (VIT) of the TPS3813J25DBVT?

The TPS3813J25DBVT has a precisely trimmed negative-going input threshold voltage (VIT) of 2.25V, with a guaranteed range of 2.20V to 2.30V over –40°C to +85°C. This value is factory-set and does not require external calibration. The device also provides 30mV of hysteresis to prevent oscillation during supply droops, making the rising threshold 2.28V. This specification is confirmed in Section 6.5 of the TI SLVS331J datasheet.

How is the 25ms reset delay implemented in the TPS3813J25DBVT?

The TPS3813J25DBVT implements a fixed 25ms typical reset delay (t_d) using an internal RC timer that starts counting only after VDD rises above the 2.25V threshold. This delay holds RESET low to ensure complete power rail stabilization and clock lock before releasing the microcontroller. The actual delay ranges from 20ms to 30ms across temperature and voltage, as specified in Section 6.7 of the datasheet. No external components are needed.

Can the TPS3813J25DBVT watchdog window be configured without external components?

Yes-the TPS3813J25DBVT supports fully pin-configurable watchdog timing. Connecting WDT to GND sets the upper timeout to 0.25s; connecting it to VDD sets it to 2.5s. Similarly, WDR tied to GND yields a 1:31.8 window ratio, while WDR tied to VDD gives 1:127.7. These four combinations require no capacitors or resistors. External capacitors on WDT (155pF–63nF) enable fine-grained tuning, but are optional.

What is the maximum sink current capability of the TPS3813J25DBVT RESET output?

The TPS3813J25DBVT RESET pin is an open-drain output rated for a maximum low-level output current (I_OL) of 5mA. At 500µA load and VDD = 2V–6V, the low-level output voltage (V_OL) is guaranteed ≤0.2V. This allows direct interface with most microcontroller RESET inputs and supports pull-up to voltages up to 6V-enabling level translation in mixed-voltage systems without additional logic.

Does the TPS3813J25DBVT require a bypass capacitor on VDD?

Yes-a 0.1µF ceramic bypass capacitor is required between VDD and GND, placed as close as possible to the TPS3813J25DBVT pins. This stabilizes the internal bandgap reference and ensures reliable power-on reset assertion. The datasheet explicitly states this in Section 7.3.1 and Figure 8-1. Omitting it risks erratic RESET behavior, especially during transient load conditions or rapid VDD ramp-up.