I've designed a circuit with CP2102. Please find the eagle schematic file here https://drive.google.com/file/d/1EHs33n2UcIHdwup-5k_3nsP4D_qBC7Kx/view?usp=drivesdk
Please let me know why the PCB is not getting recognised by the PC at all??
And here is a working circuit of mine:
I'm using the QFN24, and you're using the QFN28, but most things are similar.... a couple things jump at me (and I'm just going by memory... haven't looked these things up!):
1. !SUSPENDB is floating on yours, I have mine pulled low through a 10k
2. !RSTb - I have a 1k, you have a 10k (I wouldn't think that matters however)
3. VREGIN and VBUS - I have the resistor divider on VREGIN, yours is tied to VBUS
As I said, I haven't looked it up, but maybe some things to check! (I've built hundreds with this circuit, btw)
I guess this is a BUS-Powered design (refer figure 2.1 of datasheet).
1. pay special attention on the VBUS pin. refer to figure 2.5 of datasheet. you need a voltage driver for VBUS.
2. follow the guide in the datasheet. try to populate 4.7uF+0.1uF for VDD and VREGIN.
3. Be sure the pin sequence on the USB connector/receptor is correct (VB/D0/D+/ID/GND).
Hi Paul Vint,
Thanks for your very detailed answer. But, is it mandatory to have that voltage divider? because basically the voltage divider feeds 3.4V to VBUS pin of CP2102N which is little odd. And also I have seen some circuits like following where just two caps are used and the circuit is done. Is the following circuit correct? Or which chip should I use in case if I want to make a circuit something as follwing?
Divider for the VBUS:
And also I have seen some circuits like following where just two caps are used and the circuit is done. Is the following circuit correct?
Where you get the circuit? Is it for CP2102N?
It did not follow the guideline. Datasheet have below picture.
You may also refer the miniEK reference design.
You can take a look at this document.
Thanks for the app note. So, it basically says I can replace it right.