Texas Instruments TPS3305-25DGN

Overview

TPS3305-25DGN from Texas Instruments is a dual-voltage supervisor IC designed for DSP- and processor-based systems requiring independent monitoring of core (2.5 V) and I/O (3.3 V) rails. It features fixed 200 ms power-on reset delay, watchdog timer with 1.6 s timeout, ±40 µA supply current, and operates from 2.7 V to 6 V over –40°C to +85°C - deployed in industrial embedded controllers and portable computing power sequencing.

For engineers reviewing the TPS3305-25DGN datasheet, TPS3305-25DGN pinout, TPS3305-25DGN application, or TPS3305-25DGN equivalent, key selection criteria include dual-threshold sensing (2.25 V / 2.93 V), active-high and active-low RESET outputs, HVSSOP-8 package thermal performance, and watchdog input timing compliance.

Technical Context

The TPS3305-25DGN implements two independent voltage-sense comparators with temperature-compensated 1.25 V reference, each feeding a latch-and-timer circuit that asserts RESET on threshold violation. Its watchdog logic monitors WDI toggling and triggers RESET if no transition occurs within 1.6 s (typ), with propagation delays under 5 µs from SENSEn to RESET.

RESET assertion is synchronized to a factory-programmed 200 ms delay after both SENSE1 and SENSE2 return above their thresholds (2.25 V and 2.93 V respectively); MR input provides manual reset override with 0.3×VDD/0.7×VDD logic thresholds and <500 ns propagation delay.

Key Specifications

Pinout & Package

HVSSOP-8 (DGN) package: 3 mm × 3 mm, 0.65 mm pitch, 1.1 mm max height, exposed thermal pad (Pin 9) - optimized for high-density PCB layouts and thermal dissipation in compact systems.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-supervisor applications.

Compared with TPS3305-25DR, the TPS3305-25DGN offers superior thermal dissipation and 40% smaller PCB footprint; versus MAX6816EUT+T, it delivers integrated dual-rail supervision and watchdog - eliminating design complexity and component count in multi-rail systems.

Availability

TPS3305-25DGN is available at Aetrix Electronics and suitable for industrial PLC controllers, portable medical monitors, automotive infotainment head units, and notebook embedded controllers requiring stable component supply across extended product lifecycles.

Supply support for TPS3305-25DGN 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 supervisory circuits.

The TPS3305 family was engineered specifically for dual-rail DSP and processor systems - delivering precise, low-power voltage monitoring and watchdog protection in compact packages for space-constrained industrial and portable electronics.

FAQ

What is the exact voltage threshold for SENSE1 on the TPS3305-25DGN?

The TPS3305-25DGN has a nominal SENSE1 threshold of 2.25 V (typical), with guaranteed range of 2.20 V to 2.30 V at +25°C and 2.20 V to 2.32 V across –40°C to +85°C. This threshold is factory-trimmed and applies specifically to the -25 variant, matching its 2.5 V nominal monitored rail.

Does the TPS3305-25DGN require an external capacitor for reset timing?

No, the TPS3305-25DGN does not require an external capacitor for reset timing. Its 200 ms power-on reset delay is factory-programmed and internally generated - eliminating timing capacitor placement, tolerance drift, and associated board area in designs using TPS3305-25DGN.

Can the TPS3305-25DGN supervise voltages other than 2.5 V and 3.3 V?

The TPS3305-25DGN is specifically trimmed for 2.5 V (SENSE1) and 3.3 V (SENSE2) rails. While its absolute input range is 0–(VDD + 0.3) V, the internal comparator thresholds are fixed; for other nominal voltages, TI offers TPS3305-18 (1.8 V/3.3 V) and TPS3305-33 (3.3 V/5.0 V) variants - not the TPS3305-25DGN.

What is the function of Pin 9 on the TPS3305-25DGN HVSSOP package?

Pin 9 on the TPS3305-25DGN is the exposed thermal pad, electrically connected to GND. It must be soldered to a PCB thermal plane to meet power dissipation ratings (1.37 W at +70°C) and ensure stable operation - not a signal pin, but critical for thermal reliability in the TPS3305-25DGN.

How does the watchdog timer in the TPS3305-25DGN interact with the reset outputs?

The watchdog timer in the TPS3305-25DGN asserts both RESET (Pin 5, active-low) and RESET (Pin 6, active-high) outputs when the WDI pin remains static for >1.6 s (typ). This action is independent of SENSE1/SENSE2 status and overrides normal reset timing - ensuring TPS3305-25DGN forces system reboot on firmware hang.