7.8

VBUS discharge

VBUS discharge is activated via I2C bus and controlled via firmware by the USB-C power delivery controller.

The VBUS discharge feature integrated in TCPP02-M18 allows to discharge 10 µF in less than 220 ms

(TDIS_VBUS).

This discharge time is in line with USB-C specification, extracted below for VBUS discharge:

Table 15. Common source electrical parameters from USB-C specification

Parameter

Description

Min.

Typ.

Max.

Units

tSafe0V

Time to reach

vSafe0V max.

-

-

650

ms

tSafe5V

Time to reach

vSafe5V max.

-

-

275

ms

7.9

VCONN discharge

VCONN discharge is activated via I2C bus and controlled via firmware by the USB-C power delivery controller.

The VCONN discharge feature integrated in TCPP02-M18 allows to discharge VCONN in RDIS_VCONN < 5.5 kΩ, as

per USB-C specification table extracted below:

Table 16. VCONN source characteristics from USB-C power delivery specification

Minimum

Maximum

Notes

Rdch

30 Ω

6120 Ω

Discharge resistance applied

in UnattachedWait.SRC

between the CC pin being

discharged and GND.

Note:

•

VCONN discharge is activated and stopped via I2C commands from USB-PD controller

•

To avoid short-circuit, VCONN discharge cannot be activated if VCONN switch are closed

•

The CCxc pin discharged is the last one acting as VCONN

7.10

OTP (over temperature protection)

Above 150°C typ., the OTP triggers the FLGn pin.

OVP and OCP on VCONN, CC lines, VBUS are shut down.

Auto recovery is ensured when the temperature goes back below OTP threshold.

TCPP02-M18

VBUS discharge

DS13787 - Rev 4

page 16/27