PRELIMINARY Functional Overview USB-C Subsystem This subsystem provides the interface to the Type-C USB port and comprises the following: ■ USB-PD Physical Layer (only Rp terminations and Line-Comparators) ■ VCONN FETs ■ ADC ■ Undervoltage, overvoltage, and reverse-current protection on VBUS ■ High-side current sense amplifier for VBUS with OCP and short-circuit protection (SCP) ■ VBUS Discharge ■ Gate Driver for VBUS NFET ■ Charger Detect USB-PD Physical Layer The USB-C subsystem contains the USB-PD physical layer block and supporting circuits. The USB-PD Physical Layer consists of only two Deep Sleep comparators that are used to detect Type-C attach/detach, CC line activity events, and determine the voltage range on the chosen CC line. In addition, the block includes Rp termination and their switches as required by the USB Type-C spec. The Rp termination is implemented using current sources to indicate the current profiles supported by DFP. VCONN FET ACG1F has power supply input V5V pin for providing power to EMCA cables through integrated VCONN FETs. There are two VCONN FETs in ACG1F to power either CC1 or CC2 pins. These FETs are capable of sourcing maximum of 1.0W on the CC1 or CC2 pin to power active EMCA cables. At any given time, only one of the VCONN FETs shall be ON. The floating V5V pin should not cause ACG1F to malfunction and draw more current. ADC ACG1F has one low-footprint 8-bit SAR ADC available for general purpose A-D conversion applications in the chip. The ADC can be accessed from the GPIOs through an on-chip analog mux. Undervoltage and Overvoltage Protection on VBUS The chip implements an undervoltage/overvoltage (UVOV) detection circuit for the VBUS supply. The thresholds for both OCP and UVOV are made programmable. High-side Current Sense Amplifier for VBUS The chip supports the programmable threshold VBUS current sensing through the VBUS path. External resistor (5 m) placed in the connector VBUS path connects to the chip, and the drop across this resistor is monitored to sense the magnitude of current. Document Number: 002-26356 Rev. *C ACG1F VBUS Reverse Current Protection ACG1F restricts reverse current to zero on the VBUS provider path when Type-C VBUS is greater than VIN (provider voltage before the VBUS NFET). ACG1F reacts quickly (less then 1 µs -Typ) and turns off the VBUS provider NFET. VBUS Discharge The chip supports 21.5-V VBUS discharge circuitry inside the 40-QFN package and 5-V VBUS discharge circuitry inside the 24-QFN package. After cable removal detection, the chip will discharge the residual charge and bring the floating VBUS back to 0.8 V. VBUS Load Switch ACG1F has an integrated VBUS provider load switch, which includes OVP, OCP, SCP, RCP protection, and high-side current sense amplifier. ACG1F supports thermal protection where the load switch is turned OFF when the on-chip temperature rises above the threshold temperature and turns ON the load switch when the device temperature falls below threshold temperature. Gate Driver for VBUS NFET ACG1F has an integrated gate driver to drive NFETs on the VBUS provider path. Charger Detect The chip implements battery charger emulation (source) for USB BC.1.2. MCU and Memory CPU The Cortex M0 in ACG1F is part of a 32-bit MCU subsystem, which is optimized for low-power operation with extensive clock gating. The CPU also includes a serial wire debug (SWD) interface, which is a 2-wire form of JTAG. The debug configuration used for ACG1F has 4 break-point (address) comparators and two watchpoint (data) comparators. Flash The 16-KB integrated Flash memory shall store the firmware implementing Type-C functionality. The 16-KB flash shall support in-system firmware upgrade through the SWD or I2C interface A section of Flash can be used for storing Device/System power parameters. SROM The 32-KB SROM contains boot and configuration routines. The SROM will also be used for storing frequently-used functionalities in the firmware. SRAM The 4-KB RAM is used under software control to store temporary status of system variables and parameters. Page 4 of 27