topic Re: MC34844 - 10 Channel LED Backlight Driver in Other NXP Products

MC34844 - 10 Channel LED Backlight Driver

lvza — Sun, 22 Oct 2023 16:23:21 GMT

Hello! Is it possible to turn off LED channels in manual operation mode without using I2C? In other words: our solution does not involve the use of any microcontroller and must control 16 LED strings. Thus, I have 4 free channels out of 10x2=20.

As an option: maybe it is possible to connect unused channels to the VOUT bus (like the LT3754), or through a resistor to the GND bus (like the A80606)?

Thanks in advance for your answer.

Re: MC34844 - 10 Channel LED Backlight Driver

guoweisun — Mon, 23 Oct 2023 01:25:30 GMT

In manual mode pull low the EN to shut down this IC:

Re: MC34844 - 10 Channel LED Backlight Driver

lvza — Mon, 23 Oct 2023 10:59:02 GMT

Dear guoweisun,

Of course, I read the manual very carefully. And I understand very clearly how to turn off all channels. There are no problems with this. But, I need to exclude several channels from work in MANUAL MODE (without using the I2C bus).

How can I use the MC34844 with SIX LED strings instead of TEN without using the I2C bus?

As an option: maybe it is possible to connect UNUSED FOUR LED Channels (I6-I9 Inputs, look 34844 Pin Definitions on the Datasheet, page 5) LED string connections) to the VOUT bus (like the LT3754), or through a resistor to the GND bus (like the A80606)? Thanks in advance for your answer.

Re: MC34844 - 10 Channel LED Backlight Driver

guoweisun — Tue, 24 Oct 2023 02:02:03 GMT

You can follow below connecting way, unused channel directly connect with Ground: