TPS61500: Realize constant voltage boost circuit with TPS61500

Hi Conor,

In my understanding, the constant voltage required in LCD is supplied with "LCD Bias driver" and the constant current is supplied with "Backlight LED driver". Actually we have both type solutions. I can recommend those devices if you could share with me some more detailed spec requirements.

Theoretically, I think it is okay to use TPS61500 as constant voltage supply if you replace the LEDs with resistors. But this device was not designed in such application so my concern is that whether there will be unexpected issues like loop stability.

BR

Patrick

Hi Patrick,

Patrick Yao said:

I can recommend those devices if you could share with me some more detailed spec requirements.

I have listed the specifications required for an LCD in the attachment, so would it be possible for you to suggest the most suitable product?

LCD backlight requirement specifications.xlsx

Thanks,

Conor

Hi Conor,

I noticed the LCD 4,5,6,7 are "built into the LCD", so do you only need our device to provide the LCD 1,2,3 rails?

BR

Patrick

Hi Patrick,

LCDs 4 to 6 have PWM dimming built-in, so this function is not necessary. LCD1~3 require this function on the power supply circuit side. We are looking for an IC that can be used as a backlight for any LCD.

Thanks,

Conor

Hi Conor,

So you need 3 separate devices to fit LCD 1~3 requirements, is my understanding correct?

BR

Patrick

Hi Patrick,

Yes, but It would be better if it could be controlled by a common IC if possible.

Thanks,

Hi Conor,

TPS61500 can handle the LCD 1~3 separately, you can adjust R3 in datasheet typical application schematic for different LED current.

BR

Patrick