Automotive USB charging head unit
The USB Charging module for the head unit application is also referred to as Break-out-Box (BoB) module. The module supports USB-C Power Delivery (max of 100W) along with USB Data connectivity from a Phone, to support Apple CarPlay or Android Auto, or a USB Storage Device to stream content. The module could also support a USB Hub (to connect more than one USB Device to the module) to connect to the Head Unit, with one USB Cable.
The USB PD Controller (CCG7D) is a Dual Port USB PD Controller with Integrated DC-DC Buck-Boost Controller. Based on an ARM processor with 128KB Flash and GPIOs, CCG7D can interface with the USB Hub over the I2C interface. The Head Unit or Board Control Module (BCM) can interact with CCG7D via the USB Hub and over the I2C interface. Infineon has developed a software interface protocol (called Host Protocol Interface – HPI) in CCG7D to share the USB-PD port status with Head Unit or BCM. The HPI interface can also be used by the Head Unit and BCM to control the CCG7D’s functionality.
When connected to the Head Unit, CCG7D can receive certified firmware Over The Air (via the LTE or WiFi interfaces) or via the OBD port. CCG7D uses Root of Trust Public Key (RoTPK), RSA-2048, and SHA-256 Crypto Algorithms to validate the firmware before updating its internal Flash, with the new firmware. This feature enables CCG7D to be up to date with changing USB standards and any updates needed to the Firmware for better functionality, even after the Automotive is out of the manufacturers production line.
CCG7D is the heart of the BoB, which integrates a 24V LDO enabling CCG7D to be powered up from the Automotive Battery, after the Input Filter Module. The internal DC-DC Buck-Boost controllers drive the external Dual H-Bridge Switching FETs, with Current Sense Amplifiers for protection. CCG7D integrates VCONN FETs to detect Electronically Marked USB Type-C Cables that supports 5A. CCG7D can accept up to 4 NTC Thermistors to measure the temperature of the module, these measurements will be used to throttle the output power.
CCG7D with integrated features and automotive software offers the following Value Added Features for Automotive Applications:
- Dynamic Load Sharing between the USB-C Ports
- I2C interface to USB Hub
- Output Power Throttling based on Temperature and Battery Voltages
- Authenticated Firmware Update
- Black Box Feature – to store a number of fault occurrences for diagnostics
- Support for Programmable Power Supply (optional spec of USB-C Power Delivery)
- VBATT to GND Short Protection