Texas Instruments TPS3306-25QDRQ1

Overview

TPS3306-25QDRQ1 from Texas Instruments is an automotive-grade dual supervisory circuit for DSP and processor-based systems, monitoring 3.3 V and 2.5 V supply rails with threshold voltages of 2.93 V and 2.25 V respectively, featuring a 100-ms power-on reset delay, 0.8-s watchdog timeout, and open-drain RESET/PFO outputs. It operates across −40°C to 125°C and draws only 15 µA typical supply current.

For engineers reviewing the TPS3306-25QDRQ1 datasheet, TPS3306-25QDRQ1 pinout, TPS3306-25QDRQ1 application, or TPS3306-25QDRQ1 equivalent, key selection considerations include dual-voltage supervision accuracy, watchdog timing tolerance, automotive temperature compliance, open-drain output drive capability, and SOIC-8 package compatibility in safety-critical embedded control designs.

Technical Context

The TPS3306-25QDRQ1 integrates two independent voltage comparators with fixed thresholds (2.93 V on SENSE1, 2.25 V on SENSE2), a 100-ms reset delay timer, and a retriggerable watchdog circuit with 0.8-s timeout. Its internal 1.25-V reference enables configurable PFI monitoring via external resistor dividers.

RESET assertion occurs when either SENSE input falls below its threshold or the watchdog times out; RESET remains active until both SENSE inputs exceed thresholds for ≥100 ms. The PFO output asserts low when PFI drops below 1.25 V, supporting low-battery or auxiliary rail monitoring independent of VDD.

Key Specifications

Pinout & Package

TPS3306-25QDRQ1 is housed in an 8-pin SOIC (D) package with 1.27-mm pitch, 3.9-mm body width, and 1.75-mm max height, compliant with JEDEC MS-012AA and RoHS.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3306-25QDRQ1, the TPS3306-25QDRQ1.A offers identical supervision performance in an alternate packaging variant, while the TPS3839G33QDBVRQ1 sacrifices dual-rail monitoring, watchdog, and PFI to achieve smaller size and lower cost-making it unsuitable for applications requiring comprehensive fault coverage.

Availability

TPS3306-25QDRQ1 is available at Aetrix Electronics and suitable for automotive engine control units, ADAS camera modules, and infotainment head units requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for TPS3306-25QDRQ1 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 automotive ICs, with decades of experience in high-reliability power management and supervision solutions.

The TPS3306-Q1 product line delivers AEC-Q100 qualified dual-supply supervisors for safety-critical automotive electronics, designed specifically to meet stringent voltage accuracy, timing stability, and thermal robustness requirements in ECUs and ADAS systems.

FAQ

What is the exact voltage threshold monitored on SENSE2 for TPS3306-25QDRQ1?

The TPS3306-25QDRQ1 monitors SENSE2 at a nominal 2.5-V rail with a negative-going input threshold voltage (VIT) of 2.25 V (typical), with min/max values of 2.18 V and 2.34 V over −40°C to 125°C. This threshold is factory-trimmed and specified in the Electrical Characteristics table of the official datasheet (SGLS241B).

Does TPS3306-25QDRQ1 require external components to function as a basic dual-supply supervisor?

TPS3306-25QDRQ1 requires only external pull-up resistors on RESET and PFO (open-drain outputs), plus decoupling capacitors on VDD and GND. No external timing components are needed-the 100-ms reset delay and 0.8-s watchdog timeout are fully integrated. SENSE1 and SENSE2 connect directly to the monitored rails.

Can the watchdog timer in TPS3306-25QDRQ1 be disabled, and how?

Yes, the watchdog timer in TPS3306-25QDRQ1 is disabled by leaving the WDI pin unconnected (high-impedance). The datasheet confirms that an unconnected or high-Z WDI disables the watchdog function and causes internal retriggering-no external pull-up or pull-down is required to disable it.

What is the minimum VDD voltage at which TPS3306-25QDRQ1 asserts RESET during power-up?

TPS3306-25QDRQ1 asserts RESET when VDD rises above 1.1 V. This power-up reset voltage is guaranteed across temperature and process variation, enabling reliable reset generation even during slow-ramp or brownout-recovery conditions before the main supply reaches nominal levels.

Is TPS3306-25QDRQ1 pin-compatible with other members of the TPS3306-Q1 family?

Yes, all TPS3306-Q1 variants-including TPS3306-15QDRQ1, TPS3306-18QDRQ1, TPS3306-20QDRQ1, TPS3306-25QDRQ1, and TPS3306-33QDRQ1-share identical SOIC-8 (D) package, pinout, and terminal functions. Only the internal voltage thresholds differ, making them direct hardware replacements when adjusting supervised rail combinations.