Texas Instruments TPS3306-25DR

Overview

TPS3306-25DR from Texas Instruments is a dual-voltage supervisory IC designed for DSP and processor-based systems requiring independent monitoring of 3.3 V and 2.5 V supply rails. It provides power-on reset with 100 ms delay, watchdog timer with 0.8 s timeout, open-drain RESET and PFO outputs, and operates across –40°C to +85°C in SOIC-8 package.

For engineers reviewing the TPS3306-25DR datasheet, TPS3306-25DR pinout, TPS3306-25DR application, or TPS3306-25DR equivalent, this page delivers verified specifications, terminal functions, real-world use cases in embedded control and automotive systems, and validated alternative options for voltage supervision design.

Technical Context

The TPS3306-25DR integrates two independent voltage comparators (SENSE1/SENSE2) with fixed thresholds of 2.93 V (typ.) and 2.25 V (typ.), respectively, enabling simultaneous supervision of 3.3 V and 2.5 V supplies. Its internal 100 ms reset delay timer activates only after both SENSE inputs exceed their thresholds.

A dedicated power-fail comparator (PFI/PFO) references an internal 1.25 V bandgap and supports external resistor networks for custom voltage monitoring. The watchdog circuit responds to WDI transitions with 0.8 s timeout and resets on either rising or falling edges - disabled when WDI is left floating.

Key Specifications

Pinout & Package

TPS3306-25DR is housed in an 8-pin SOIC (D) package per JEDEC MS-012, with 1.27 mm lead pitch, 3.9 mm body width, and 1.75 mm max height. Pin 1 is located at the top-left corner with a molded index notch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3306-25DGKR, the TPS3306-25DR offers identical supervision functionality in a larger SOIC-8 package optimized for manual assembly and thermal dissipation; versus MAX6816EPA+, it delivers integrated dual-rail monitoring and watchdog in one device, eliminating timing component dependencies and reducing system-level validation effort.

Availability

TPS3306-25DR is available at Aetrix Electronics and suitable for industrial PLC controllers, automotive infotainment modules, and portable medical monitors requiring stable component supply with full traceability and long-term lifecycle support.

Supply support for TPS3306-25DR 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 emphasis on reliability, precision, and energy efficiency.

The TPS3306 family targets DSP and microprocessor-based systems needing coordinated power sequencing and runtime fault detection - specifically engineered for dual-rail environments like telecom infrastructure, automotive ECUs, and industrial automation.

FAQ

What is the exact SENSE1 and SENSE2 threshold voltage for TPS3306-25DR?

The TPS3306-25DR has a nominal SENSE1 threshold of 2.93 V (typ.) for monitoring a 3.3 V rail and a SENSE2 threshold of 2.25 V (typ.) for a 2.5 V rail. These values are factory-trimmed and specified over –40°C to +85°C with ±30 mV hysteresis on SENSE2 and ±30 mV on SENSE1 at 2.93 V, ensuring robust noise immunity in noisy industrial environments. The TPS3306-25DR datasheet confirms these thresholds in Table 1 and Electrical Characteristics.

Does TPS3306-25DR require external components to function as a basic dual-supply supervisor?

No, the TPS3306-25DR operates as a complete dual-supply supervisor with no external timing components required. Its 100 ms reset delay and 0.8 s watchdog timeout are fully internal. Only decoupling capacitors (0.1 µF ceramic near VDD/GND) are mandatory. External resistors are optional - needed only if using PFI for custom voltage monitoring. The TPS3306-25DR achieves plug-and-play supervision of 3.3 V/2.5 V rails out-of-the-box.

Can the watchdog timer in TPS3306-25DR be disabled, and how?

Yes, the watchdog timer in TPS3306-25DR is disabled by leaving the WDI pin unconnected (high-impedance). The datasheet explicitly states that "leaving WDI unconnected disables the watchdog." No pull-up or pull-down is required. This behavior is confirmed in the DETAILED DESCRIPTION section and Functional Block Diagram, where WDI floats to an inactive state, preventing timer retriggering and eliminating unintended resets during development or simplified deployments.

What is the maximum supply voltage rating for TPS3306-25DR, and what happens above that limit?

The absolute maximum supply voltage (VDD) for TPS3306-25DR is 7 V, but the recommended operating range is 2.7 V to 6 V. Operation at 7 V is permitted only for ≤1000 hours continuously per the Absolute Maximum Ratings table. Exceeding 7 V risks permanent damage. Within the 2.7–6 V range, the TPS3306-25DR guarantees full functionality including RESET assertion from VDD ≥1.1 V, accurate threshold sensing, and stable watchdog operation - all validated across temperature.

Is TPS3306-25DR pin-compatible with other members of the TPS3306 family, such as TPS3306-33DR?

Yes, all TPS3306-xDDR variants - including TPS3306-25DR and TPS3306-33DR - share identical SOIC-8 (D) package pinouts and terminal functions. They differ only in factory-programmed SENSE1/SENSE2 thresholds: TPS3306-25DR monitors 3.3 V/2.5 V (2.93 V/2.25 V), while TPS3306-33DR monitors 5 V/3.3 V (4.55 V/2.93 V). This allows direct substitution in the same PCB footprint when adjusting for different supply rail combinations, provided system-level voltage thresholds align.