TCAN4550-Q1: schematic review

Hi Denny,

I have reviewed the schematic and it looks pretty good.

I wanted to point out that by default nWKRQ is supplied from an internal 3.6V rail, but it can be configured as an Open-Drain that would require a pull-up resistor to VIO (3.3V).  The schematic has a 10k resistor to SYS_3V3 that looks to be installed by default.  Unless they add the open-drain configuration settings to their initialization sequence, there will be some leakage through the nWKRQ pin (3.6V to 3.3V).  I would recommend making R408 Not Mounted (N.M) by default.

The crystal oscillator circuit looks good.  I will point out that the TCAN4550-Q1 supports both a crystal and a single-ended clock input.  Because of this, the components chosen (load capacitors, series dampening resistor, etc.) may need to be adjusted based on the PCB parasitic capacitance and the motional parameters of the specific crystal that will be used.  These values look good as a starting point and there is an application note that has been published to give additional information on how to optimize the clock circuit.  It can be found on the TCAN4550-Q1 product folder on ti.com.

Regards,

Jonathan