9.3.2 TVSP Device Configuration and ESD Protection
The Transient Voltage protection and
firmware Setting Pin (TVSP) has three functions: 1) Boot
configuration settings; 2) USB connector pin short to VBUS or
VBAT protection; and 3) USB connector pin enhanced ESD protection.
RTVSP: At power on, the resistance
between the TVSP pin and PGND determines the boot method, USB PD port
I2C addresses and I2C logic thresholds. Refer to
Table 9-3. The most
common configuration is shown in Figure 9-4 with RTVSP open, corresponding to TVSP Index 0. During device
initialization and boot, typically within 4 seconds after power on,
VIN must be above 7.6 V to ensure proper bias of the TVSP pin
to 5.5 V. Once boot is complete the device can operate over the full
VIN range.
CTVSP: A 0.1-µF capacitor
(CTVSP) must be connected to PGND. Place
CTVSP as close to the TVSP pin as possible to minimize
parasitic inductance. CTVSP is part of the centralized protection
circuitry fortifying connector pins Px_CCy, Px_DP and Px_DM from damage
during short to VBUS, VBAT and ESD events. A 40-V
0.1-µF capacitor is recommended for proper operation of the internal TVSP
regulator circuit.
TVSP Damper Network:
Capacitance, CDAMP, and resistance, RDAMP, form an RC
network preventing excessive current from flowing inside the device durging
connector pin over-voltage and ESD events.
CDAMP: A 0.47-µF capacitor must be
connected in series with RDAMP to PGND. A 40-V 0.47-µF
capacitor is recommended.
RDAMP: A 10-Ω resistor must be
connected in series with CDAMP to PGND. A 0.25-W rating
is recommended.
Device firmware can be updated using the USB Endpoint on the PA_DP and PA_DM pins.
To enable firmware update mode, boot the device with a resistance corresponding to
Index 8 between TVPS and PGND. A boot cycle can be performed by power cycling the
device or by pulling the EN/UVLO pin momentarily below VEN(OPER)
threshold. An example circuit to enable USB Endpoint firmware update mode is shown
in Figure 9-5
Figure 9-5 Example Circuit to Enable USB
Endpoint Firmware Update Mode