F

RT7204E

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is a registered trademark of Richtek Technology Corporation.

RT7204E_DS-00

May 2024

www.richtek.com

37

For the typical protection behavior of shutdown with auto-recovery, the OPTO pin voltage will be latched low to

limit the output power until the VDD voltage drops below the VDD turn-off threshold VVDD_OFF, as shown in Figure

12. After VDD is turned off, VOPTO is released and VDD will be automatically powered up again.

VDD

t

tVDD_OVP

VOPTO

t

VBUS

t

VVDD_OFF

OV Hysteresis

VVDD_ON

VVOUT_OVP

t

Fault Flag

Figure 12. Timing Sequence of the OVP Function

16.6

Blocking N-MOSFET Control

The RT7204E provides a charge-pump driver for controlling an external blocking N-MOSFET, which is shown in

Figure 13. The N-MOSFET is activated once the communication is set up with an UFP, or a sink termination

resistor Rd at the CC1/CC2 pin of a USB Type-C connector is detected. The blocking N-MOSFET can be quickly

turned off in the event of any fault condition. In the case of a VOUT overvoltage condition, the blocking N-MOSFET

will be turned off to protect the UFP from potential damage. When VOUT is shorted to GND, the N-MOSFET will

automatically turn off, and the output power will be limited. Additionally, to prevent the IO pins from damaging due

to abnormal contact with VBUS at the USB Type-C receptacle, a quick-interruption feature is designed to turn off

the blocking N-MOSFET.

Control

Fault

VDD

USBP

VBUS

VOUT

Charge

Pump

Figure 13. Blocking N-MOSFET Control