Why automakers should be concerned with USB Type-C and USB Power Delivery?
Evolutions in Consumer electronics do affect also the Automotive market. The new USB Type-C connector has already pervaded the Computer, Mobile Phones and Tablets; consequently, car makers are forced to move from standard type B connectors to type C. This is new standard is not only replacing the connectors for infotainment data exchange and connection, but it is also invading the cigarette lighter market with the associated USB Power Delivery standard. The power capability has been elevated from 10-15W to 100W and to the 5V additional 3.3V, 9V, 15V, 20V output voltages are now available. The standard is enhanced with the Alternate mode, allowing the USB connector to become a bridge for high-speed data ports like HDMI and DisplayPort.
The possible usages of AEK-POW-L5964V1 are:
- As an MCU driven DC-DC power board with two adjustable output voltage channels. In this configuration the board could be used for Infotainment, general Body Application supply and ECU internal supply.
- As a general DC-DC power board without direct control from a MCU and where the MCU control signals (e.g. GPIOs) are replaced by direct supply signals.
- As a power board for AEKD-USBTYPEC1 kit to exploit the functionality of USB Type-C and USB Power Delivery version 2.0 (i.e. adjustable fixed voltages).
- As a power board for USB Power Delivery version 3.0 where Programmable Power Source (PPS) for current and voltage loops are required.
- As high power board up two 100W where the two channels are combined in one. This option is available on the PCB but not implemented.
Usage with AEKD-USBTYPEC1 demo kit
AEKD-USBTYPEC1 demo kit is designed for the evaluation of the USB Power Delivery protocol stack version 2.0 implemented on the ASIL-B automotive grade 32-bit Power Architecture® microcontroller.
The AEKD-USBTYPEC1 kit is composed of
- SPC58EC-DISP Microcontroller discovery board with various peripherals (CAN, LIN, Ethernet among others).
- AEK-USB-2TYPEC1 dual port USB Type-C interface board with a pair of STUSB1702Y automotive grade USB Type-C controllers.
- STSW-USB2TYPEC1 firmware (MCU flash image). The software is built with different abstraction layers and is running parallel tasks on a free real-time operating system (FreeRTOS).
- AEK-POW-L5964V1 power board (sold separately), plugged on top of the interface board, it extends available power profiles (PDOs).
- The kit is very flexible, scalable, customizable and automotive grade compliant. For example, through the Microcontroller Discovery board, you can expand your application by connecting additional boards to extend functionalities.
The SPC58EC-DISP discovery board hosts SPC58 ASIL-B automotive grade 32-bit Power Architecture microcontroller with, CAN ports, Flex port and Ethernet port among others. The microcontroller pins are multi-functions, i.e. through internal microcontroller register programming, it is possible to assign different functionalities to the same pin. The capability of SPC5 to configure its pins and the intuitive graphical interface of SPC5-Studio development environment are key elements for fast-prototyping and customizable application design.
The functional interface board, AEK-USB-2TYPEC1, hosts a pair of STUSB1702Y, automotive grade USB Type-C controller with TX/RX line driver and BMC, one for each USB Type-C port. The board contains devices for ESD protection, dual Transil™ array ESDA25LY and very low capacitance USBLC6-2SC6Y. Each port status is monitored on the board through some LEDs. One of this LED (the green one on each port) will turn-on once the power profile negotiation is successfully reached between provider and consumer.
The AEK-POW-L5964V1 is a digitally controller board hosting L5964: an automotive grade, dual channel DC-DC buck converter with up to 3A output current per channel. The board outputs are adjustable with fixed voltages (3.3V, 5V, 9V) and within the variable range 3.3V-11V with steps of 20mV, according to the newest Programmable Power Supply (PPS) definition in USB Power Delivery version 3.0. The board hosts circuitry for 15V, 20V output provided a higher input voltage is supplied to the board. The current loop with steps of 50mA in the range 0-3A according to PPS is available when the board is plugged on AEK-USB-2TYPEC1 interface board.
The firmware STSW-USB2TYPEC1 is pre-loaded on the SPC58EC-DISP discovery board.
In addition to the STSW-USB2TYPEC1 firmware, a SPC5-Studio plugin with software source code is available after registration. It contains:
- A driver dedicated to the STUSB1702Y device
- A plugin for the USB Power Delivery software stack version 2.0
- A demo application
The software can be configured via SPC5-Studio dedicated plugin graphical user interface for USB-PD stack. SPC5-Studio automatically regenerates the code without additional developer’s coding.
A specific software driver is available in the AutoDevKit™ library for AEK-POW-L5964V1: the driver has been conceived for two working modes: full features (including PPS) and basic adjustable voltage. Through the graphical user interface provided in SPC5-Studio, the user can select the preferred mode and consequently only the necessary pins are allocated. Please note that in the full feature mode the allocation is fixed because intended to be plugged on top of the AEK-USB-2TYPEC1 board. In the basic mode the pin allocation is dynamic according to the available pins in the MCU.