PCA9956B External Clock

cancel
Showing results for 
Show  only  | Search instead for 
Did you mean: 

PCA9956B External Clock

594 Views
davemarnatti
Contributor I

Greetings, I've used and external 4MHz clock to synchronize 4 pca9685 s, and would now like to do the same with the pca9956B.  The 9685 has an EXTCLK pin, a selection bit in MODE1, and even a prescaler to divide the clock down if desired.  I see a reference to external clocking in the 9956's datasheet (section 7.4), but no pin, control bit, or scaling capability.  Is what I want to do possible?  I need two of them to operate in lock step within a few nanoseconds, because I want to tie their per-channel outputs together in order to double the current.

0 Kudos
2 Replies

494 Views
AldoG
NXP TechSupport
NXP TechSupport

Hello, Dave

 

The external clock mentioned in the datasheet, is referenced to the signal applied to the OE pin which can be used as a dimming or blinking control, setting LDRx = 01 will set fully ON the outputx, then you can blink/dim the outputx, applying a clock signal, since this pin can whether turn ON or OFF the device outputs.

 

Regards, Aldo

494 Views
davemarnatti
Contributor I

Thanks for the clarification, Aldo,

Best regards,

Dave

0 Kudos