Texas Instruments TPS3306-15DGK

Overview

TPS3306-15DGK from Texas Instruments is a dual-voltage supervisory IC designed for DSP and processor-based systems requiring independent monitoring of 3.3 V and 1.5 V rails. It integrates power-on reset (100 ms delay), watchdog timer (0.8 s timeout), open-drain RESET and PFO outputs, and operates from 2.7 V to 6 V supply with 15 µA typical supply current over –40°C to +85°C.

For engineers reviewing the TPS3306-15DGK datasheet, TPS3306-15DGK pinout, TPS3306-15DGK application, or TPS3306-15DGK equivalent, this page delivers verified functional identity, exact VSSOP-8 package mapping, confirmed dual-threshold sensing (2.93 V / 1.40 V), watchdog timing behavior, and validated alternatives for multi-rail power supervision in embedded control and portable systems.

Technical Context

The TPS3306-15DGK implements two independent voltage comparators with fixed thresholds (2.93 V for SENSE1, 1.40 V for SENSE2) referenced to an internal 1.25 V bandgap, each with ~20 mV hysteresis. Its RESET output asserts low when either sensed voltage falls below its threshold or during power-up until VDD ≥1.1 V, then remains active for 100 ms after both inputs exceed their thresholds.

A dedicated PFI comparator monitors external voltages via resistor divider and drives an open-drain PFO output; the integrated watchdog accepts WDI transitions (low-to-high or high-to-low) every 0.8 s to prevent timeout-induced RESET assertion - disabling WDI by leaving it unconnected disables watchdog functionality entirely.

Key Specifications

Pinout & Package

VSSOP-8 (DGK) package: 3.0 mm × 3.0 mm body, 0.65 mm lead pitch, exposed pad optional (not electrically connected per datasheet), RoHS-compliant NiPdAu finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3306-15DR, the TPS3306-15DGK offers identical supervision functionality in a 62% smaller footprint but with lower thermal dissipation margin (220 mW vs. 377 mW at +85°C); TPS3808G15DBVR provides no dual-rail capability or watchdog, making it unsuitable as a direct alternative without redesign.

Availability

TPS3306-15DGK is available at Aetrix Electronics and suitable for industrial motor control, portable medical instrumentation, DSP-based audio processing, and automotive infotainment head units requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for TPS3306-15DGK 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 for mission-critical systems.

The TPS3306 family was engineered specifically for dual-rail DSP and microprocessor systems needing coordinated reset, watchdog protection, and auxiliary power-fail detection - targeting industrial, medical, and automotive-qualified applications.

FAQ

What is the exact voltage threshold monitored by SENSE1 and SENSE2 on the TPS3306-15DGK?

The TPS3306-15DGK monitors SENSE1 at a typical threshold of 2.93 V and SENSE2 at 1.40 V, corresponding to nominal 3.3 V and 1.5 V supply rails. These thresholds are factory-trimmed and exhibit ±3% tolerance over temperature; hysteresis is approximately 20 mV to prevent chatter near trip points. The TPS3306-15DGK datasheet Table 1 confirms these values as device-specific for the -15 variant.

Does the TPS3306-15DGK require external components to operate as a basic dual-supply supervisor?

No, the TPS3306-15DGK operates autonomously with only VDD, GND, and the two SENSE inputs connected - no external capacitors or resistors are needed for core supervision. An external pull-up resistor is required on RESET and PFO due to their open-drain architecture. The PFI input may use a resistor divider if monitoring voltages other than the primary rails, but that is optional.

Can the watchdog timer on the TPS3306-15DGK be disabled, and how?

Yes, the watchdog timer on the TPS3306-15DGK is disabled by default when the WDI pin is left unconnected (high-impedance). The datasheet explicitly states "Leaving WDI unconnected disables the watchdog." If WDI is driven, any low-to-high or high-to-low transition within 0.8 s resets the timeout; failure to do so asserts RESET for 100 ms. No register programming or external signal is required to disable it.

What is the minimum VDD voltage at which the TPS3306-15DGK asserts RESET during power-up?

The TPS3306-15DGK asserts RESET as soon as VDD reaches 1.1 V, per the "Power-up reset voltage" specification in the Electrical Characteristics table. This ensures early fault detection even before the full 2.7 V minimum operating voltage is reached. RESET remains asserted until both SENSE1 and SENSE2 exceed their respective thresholds and the 100 ms delay timer completes.

Is the TPS3306-15DGK pin-compatible with other members of the TPS3306 family, such as TPS3306-33DGK?

Yes, all TPS3306-xxDGK variants share identical VSSOP-8 pinout, package dimensions, and terminal functions - only the internal voltage thresholds differ. TPS3306-33DGK monitors 5 V / 3.3 V rails (4.55 V / 2.93 V thresholds), while TPS3306-15DGK monitors 3.3 V / 1.5 V (2.93 V / 1.40 V). Swapping them requires verifying threshold compatibility with target supply rails.