- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
Hi,
The default CCP3PA project (CY4532 EVK with CYPD3171 CLA implementation) uses direct feedback implementation. In the firmware, there's the following defines in config.h:
VBUS_CTRL_NONE (0)
VBUS_CTRL_PWM (1)
VBUS_CTRL_DIR_FB (2)
VBUS_CTRL_OPTO_FB (3)
VBUS_CTRL_TYPE_P1 (VBUS_CTRL_DIR_FB)
My hardware doesn't use the CYPD3171's Feedback pin. I am using a GPIO to toggle between 2 voltage options (5V or 9V) from my external regulator. When I use VBUS_CTRL_NONE, my application doesn't work (or run) at all because it seems VBUS_CTRL_NONE is not really implemented. If I use VBUS_CTRL_DIR_FB, my 5V (default) option works, but with all the idac calculations in vbus_ctrl.c (which I think isn't necessary for my implementation), I cannot get my 9V option to work even after setting my GPIO pin. Hardware-wise, the GPIO pin did set, but my PD analyzer keep showing "hard reset" after a successful 9V negotiation over CC pin. Maybe I am missing something in the firmware. I tried commenting out some of the idac calculations code, but that didn't work.
Is it possible to implement a no feedback option?
Thanks,
Jonathan
Solved! Go to Solution.
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
Hi Lisa,
Thanks for your reply. I've did some digging and it appears that there was a timer in the feedback code that I needed for my no-feedback implementation. I have added it to my own function and it is working now.
I have a separate question related to the CY4532 EVK, but I will create a new topic on this.
Thanks,
Jonathan