We were settling on CCG3PA in a new design which is a Type C/Type A dual port charging only, with fixed 5V supply. I had a few more questions about the implementation I was hoping to get answered:
- Does Cypress have a design/schematic check service?
- There seems to be GPIO that is preferred for certain functions in design examples (i.e. external VCONN FET enable, Type A current sensing etc.) - is there a definitive listing of these? Can this all be changed in firmware?
- There appears to be no RCP (Reverse Current Protection) on the CCG3PA - is this possible using an external current sensor (into an ADC pin) and modifying the firmware (for both Type A and Type C ports)?
- I've read in a notice and in the forums that the FW was closed source - what does this mean? Is it possible to get full access under NDA if we run into issues when we customise the higher level code?
- For CSP connection - is there a way to make this Kelvin connection? Is Pin 22 the -ve input of the current sense amplifier or is this just a general ground? Any recommendations here?
- Is there a schematic of internal PFET drivers? How does the internal pull-up on the VBUS_P_CTRL path function if VBUS_IN_DIS is used in the configuration shown here (CCG3PA Power Adapter/Car Charger (1C+1A) single chip solution hardware design tips) for a Type C/Type A port - what is it pulling up to? In this case do we need an external pull-up?
- With respect to the PFET drivers again - are they able to continuously sink current if shorted to VBUS = 20V while trying to pull-down? It would seem that with an internal pull-down of 3kΩ max the dissipation is a minimum of 133mW - can we add external resistor in series with the pin to reduce dissipation in this instance? Also noticed there is difference in sink currents vs drive strengths given (Table 32. Gate Driver DC Specifications) is there a firmware control aspect here too? I think a schematic of how this works might clarify things for me.
- Is it possible to disable FW upgrade over CC pins after an initial FW update?
- We eventually want to extend this to control an external supply up to 20V/5A - this will be over an I2C/UART comms port instead of direct feedback. Is there any device that is preferred to implement this between CYPD3171-24LQXQ, CYPD3174-24LQXQ and CYPD3175-24LQXQ? Are there any application examples of firmware/hardware modified to support digitally controlled power supply via I2C/UART/SPI?