topic PCA9956B External Clock in Other NXP Products

PCA9956B External Clock

davemarnatti — Thu, 26 Jul 2018 23:18:33 GMT

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.

Re: PCA9956B External Clock

AldoG — Tue, 31 Jul 2018 15:04:34 GMT

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

Re: PCA9956B External Clock

davemarnatti — Tue, 31 Jul 2018 20:31:50 GMT

Thanks for the clarification, Aldo,

Best regards,

Dave