question about TFT display for Newhaven

[aliyesami]

I am reading datasheet for NHD-2.4-240320SF-CTXI#-FT1 display which is a 2.4inch ILI9341 controller based display and its says the following about voltage requirements

Supply Voltage for Logic IOVDD ‐ 1.65 2.8 3.3 V
Supply Current IDD VDD=2.8V ‐ 7 9 mA
“H” Level input Vih ‐ 0.8*VDD ‐ VDD V
“L” Level input Vil ‐ GND ‐ 0.2*VDD V
“H” Level output Voh ‐ 0.8*VDD ‐ VDD V
“L” Level output Vol ‐ GND ‐ 0.2*VDD V

i can put a 3.3 v regulator on the supply volage but what do i do with the WR, D/C, RD and RES signals that are coming from the MCU ? since the data sheet is requiring High input as 0.8 xVDD .

thanks

 

[emresel]

Hi;
High input as 0.8 xVDD is minumum input for high level. Typical is vdd (ie if you supply lcd from 2.8V, you should apply High as 2.8V). By the way LCD typical supply is 2.8V not 3.3V, i advise you to supply it from 2.8V. What is your MCU supply? If it is also 2.8V no problem. But if MCU supply is 3.3V, then you need the level shifting for digital i/o's. Try to use common voltage for MCU and LCD.

Hope helps

 

[aliyesami]

hi emeresel !
i am using 3.3v for MCU, but if the datasheet of teh display saying i can go upto 3.3v why shouldnt I ?

regards

 

[amirke]

Hey aliyesami,

No real problem to use 3.3V. I would do it.
Although the data sheet is not telling what are the absolute maximum rating (poor datasheet), It does says that is allowed to use with 3.3V.

But if you insist and have a spare time, you can put regulated voltage from 3.3V to 2.8V.
You can choose from a wide line of product such as:
https://www.ti.com/lsds/ti/interface/dual-supply-translator-products.page

 

[aliyesami]

thanks for your advise. I Am moving my MPU to 3.3v also
so i wont be doing any voltage level shifting as i was previously intending.