For an automotive USB charging port, the V_BUS, D+, and D– pins are exposed and require a protection device. The protection required includes V_BUS overcurrent, D+ and D– ESD protection, and short-to-battery protection. This charging-port device protects the upstream dc-dc converter (bus line) and automotive SOC or hub chips (D+ and D– data lines). An application schematic of this circuit with short-to-battery protection is shown in Figure 9-1.

Figure 9-1 Typical Application Schematic: USB Port Charging With Cable Compensation