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TCA6507: as a PWM generator

Kai Lai
Genius 9911 points

Part Number: TCA6507
Other Parts Discussed in Thread: TPS61199

Hi Team,

Just want to check can I use TCA6507 as a fix 125Hz PWM generator ? And use the register to adjust the output duty cycle ?

I want to use this PWM signal output to our LED driver TPS61199 as the PWM input dimming.

Thanks!
Kai

  • 0
    TI__Guru 60618 points

    Hi Kai,

    TCA6507 has seven available outputs that can be configured into two banks of outputs (BANK0 and BANK1). Each bank of outputs can be independently controlled for dimming rate and intensity through the I2C bus, these rates are fully programmable. 

    The intensity of each bank of LEDs is controlled by dynamically varying the duty cycle of the signal, which has a period of approximately 8 ms (125 Hz) and a pulse rate of 125 times per second. 

    Regards,

    Tyler

  • 0 in reply to Tyler Townsend
    TI__Genius 9911 points

    Hi Tyler,

    So it mean TCA6507 can be a PWM generator right?

    I mean I can use one output channel to the LED driver instead of connect to a LED? Like below highlight.

     

  • 0 in reply to Kai Lai
    TI__Guru 60618 points

    Hi Kai,

    Yes you are correct. You can use one output channel to the LED driver as a 125 Hz PWM signal with adjustable duty cycle by changing register values via table 5 in the datasheet. 

    Please be cautious of the current through that one p-port output. The maximum continuous output LOW current of a single p-port is 50mA. Any greater current draw could cause permanent damage to the device. Also keep in mind that the maximum supply current ICC must be respected as well.

    Regards,

    Tyler

  • 0 in reply to Tyler Townsend
    TI__Genius 9911 points

    Hi Tyler,

    Thanks!

    For those unused pin, should I floating it ?   

    Customer plan to use just one output channel as a 125 Hz PWM signal source.

    Thanks!

    Kai

  • +1 in reply to Kai Lai
    TI__Guru 60618 points

    Hi Kai,

    The unused p-ports can be left floating since they are open-drain outputs. 

    Regards,

    Tyler