cancel
Showing results for 
Search instead for 
Did you mean: 

USB EZ-PD Type-C

MuIc_4620061
New Contributor II

Hi,

I would like you to have a look at following schematics and review/criticize/recommend.

It will be a UFP device with TFT-LCD display and buttons. Some blocks/components are displayed black, I don't know why.

Thanks.

0 Likes
1 Solution
MaBr_2028236
New Contributor II

Hello,

I do have a recommendation for you.

You connected your sense resistor R9 between VBUS_IN and VBUS_OUT and the CCG3 controls the power input through the power MOSFETs Q1A / Q1B which are located between the same net names (VBUS_IN and VBUS_OUT). So the sense resistor is connected in parallel to the power MOSFETs which render useless the CCG3 control since current will always flow through the sense resistor.

I would rather connect the sense resistor in series with the control MOSFETs. Depending on where you want to read the current/voltage (input or output), it could be :

USB-C connector input --> VBUS_IN --> R9 --> VBUS_IN_SENSE --> Q1A/Q1B --> VBUS_OUT --> USB-C connector output

or

USB-C connector input --> VBUS_IN --> Q1A/Q1B --> VBUS_OUT --> R9 --> VBUS_OUT_SENSE --> USB-C connector output

I also wonder what will you be connecting to the USB-C PC Power Output connector? Will you be using a standard USB-C device with PD capability? If yes, you might encounter problem since the CC lines are left unconnected on the connector output.

Hope this helps,

Best Regards,

Martin

View solution in original post

5 Replies
Sananya_14
Moderator
Moderator

Hi,

The schematic is fine. For the recommended values of capacitors on the supply pins please refer to the datasheet. Could you please let me know whether the Type-C plug or receptacle is connected to the host (DFP)? Also what the micro-B connector is used for?

Best Regards,

Sananya

0 Likes
MuIc_4620061
New Contributor II

Thanks for answer.

Type-C plug will be connected to host. Micro USB will be used for host communication. I also added a USB 2.0 multiplexer ( or switch) to swtich the host-connection between microusb and type-c plug. This device will be development board. For some tests I want to use micro usb and type-c for host-connection.

Regards.

0 Likes
MaBr_2028236
New Contributor II

Hello,

I do have a recommendation for you.

You connected your sense resistor R9 between VBUS_IN and VBUS_OUT and the CCG3 controls the power input through the power MOSFETs Q1A / Q1B which are located between the same net names (VBUS_IN and VBUS_OUT). So the sense resistor is connected in parallel to the power MOSFETs which render useless the CCG3 control since current will always flow through the sense resistor.

I would rather connect the sense resistor in series with the control MOSFETs. Depending on where you want to read the current/voltage (input or output), it could be :

USB-C connector input --> VBUS_IN --> R9 --> VBUS_IN_SENSE --> Q1A/Q1B --> VBUS_OUT --> USB-C connector output

or

USB-C connector input --> VBUS_IN --> Q1A/Q1B --> VBUS_OUT --> R9 --> VBUS_OUT_SENSE --> USB-C connector output

I also wonder what will you be connecting to the USB-C PC Power Output connector? Will you be using a standard USB-C device with PD capability? If yes, you might encounter problem since the CC lines are left unconnected on the connector output.

Hope this helps,

Best Regards,

Martin

View solution in original post

MuIc_4620061
New Contributor II

Hi,

Oh yes, you are right. I must have been overseen that the current sense resistor is parallel to MOSFET.

Power output will be used for non-PD devices.

MaBr_2028236
New Contributor II

Hi,

It should be fine then if using non-PD devices.

By the way, concerning the blocks that are displayed black.

You seem to be using Altium designer. Have you used Altium's command "Smart PDF..." in file menu to generate the PDF?

I've had some display problem myself when generating PDF using other methods than "Smart PDF..."

Cheers,

Martin

0 Likes