Description:

In automotive microcontroller or microprocessor power-supply applications, a watchdog is used to monitor the operating state of the microcontroller to prevent the software from running out of control. To ensure system reliability, the watchdog must be independent of the microcontroller. The TPS7B63-Q1 is a 300-mA watchdog low-dropout regulator (LDO) rated for operation up to 40 V, with a typical quiescent current of only 19 µA under light-load conditions. The device integrates programmable features for selecting either a window watchdog or a standard watchdog, and uses an external resistor to set the watchdog time with 10% accuracy.

Features:

AEC-Q100 qualified for automotive applications:

Temperature grade 1: –40°C to 125°C, TA

Maximum output current: 300 mA

Wide VIN input voltage range of 4 V to 40 V, with transient voltages up to 45 V

Fixed 3.3-V and 5-V outputs

Maximum dropout voltage: 400 mV (300 mA)

Stable with output capacitors across a wide capacitance range (4.7 µF to 500 µF) and ESR range (0.001 Ω to 20 Ω)

Low quiescent current (I(Q)):

< 4 µA when EN is low (shutdown mode)

19 µA typical at light load (WD_EN high, watchdog disabled)

Configurable as a window watchdog or a standard watchdog

Open/close window ratio configurable as 1:1 or 8:1

Fully adjustable watchdog period (from 10 ms to 500 ms)

Watchdog period accuracy of 10%

Dedicated WD_EN pin for controlling the watchdog on/off

Fully adjustable power-good threshold and power-good delay period

Low input voltage tracking for UVLO

Integrated fault protection:

Overload current-limit protection

Thermal shutdown

Functional Safety-Capable:

Documentation available to aid functional safety system design

16-pin HTSSOP package

Applications:

Automotive MCU power supply

Body control module (BCM)

Seat comfort module

EV and HEV battery management system (BMS)

Electronic gear shifter

Transmission

Electric power steering (EPS)