LM36923: Brightness Control

Hi Teboho,

You must use either PWM or I2C to set brightness, both cannot be left unconnected.  The default settings enable PWM control for PWM frequency < 10kHz.  If your PWM frequency is > 10 kHz you will need I2C control to change the PWM sample frequency in register 0x12.

Best regards,

Randy

Hi Randy 

Thanks for the reply.

I want use the device as a stand alone. Can I set the brightness first then leave the device to work as stand alone with the pins not connected?

Hi Teboho,

You could connect the PWM pin to VIN with a pull-up resistor to turn on the Boost and LED current sinks. If you let the PWM pin float the boost will turn off.
Best regards,
Randy

Hi Randy

I will share my schematic soon for you to review. Thanks

Hi Randy

Please review my schematic. HWEN and ASEL are connected to external connectors for manual selection. I'll be using Arduino to configure brightness control, can you provide me with the code to do this. Also I've driven PWM highfor standalone mode. ThanksBLU LED Driver LM36923H.pdf

Hi Teboho,

Can you provide more information regarding standalone mode?

Are you disconnecting PL3 and PL4 in standalone mode? If yes you will need a pullup on HWEN pin D2.

The capacitor values are not shown on your schematic, otherwise the schematic is okay.

We do not have any Arduino code for this device.

best regards,

Randy

Hi Randy

What I meant by standalone is that the device is self-contained and there won't be any connections to it as you mentioned I'll be disconnecting PL3 for I2C writes (SCL SDA), PL4 won't be disconneced it will be just to enable and disable the LED driver, will I still need a pull'up on it as well?. My capacitor values are 2.2uF on D3 and 1uF on C3. Will I need pull-ups on ASEL as well?