2014-11-27 01:55 AM
Hi,
I want to connect LCD to the ST using VLCD pin , but instead of 3V i need 4.5 V. I found in data sheet that there is stepup converter (kind of SW configurable DC2DC) that can be used for this purpose but i couldn't find any other information - how to handle it by software. 1) is it correct ? 2) if yes, how to configure it. Thanks in advance , Moran. #lcd #stm32l1 #vlcd2014-11-28 02:13 AM
> I want to connect LCD to the ST using VLCD pin , but instead of 3V i need 4.5 V.
You can't. The maximum voltage on VLCD pin is 3.6V.> I found in data sheet that there is stepup converter (kind of SW configurable DC2DC) that
> can be used for this purpose but i couldn't find any other information - how to handle it by > software. All the information you need is in RM0038 and the datasheet. The steupup is switched on by clearing VSEL bit in LCD_CR and its output controlled by CC[2:0] bits in LCD_FCR; in that case you need to have a capacitor connected to VLCD instead of external voltage source. But don't hope for output higher than 3.6V - this chip is simply not capable of handling higher voltages. You'll need to use the LCD accordingly. JW2014-11-30 12:27 AM
Thanks alot JW.
I've read the reference but couldn't understand what should I do if I need 4.5V instead of maximum 3.6V for better contrast.