stm32L073 LCD drive voltage

[Nabu .1]

Hi,

I plan to use STM32L073 to drive my 7segment LCD. The LCD maker not able to design 3.3V LCD due to the cycle size. I am using 1/8 cycles. 1/3 bias but with 5V operating voltage.

The problem is, I've read the datasheet mention that I only can drive LCD up to 3.6V max.

So how do I need to drive my LCD with 5V voltage using L073?

Or is there any other solution to make this thing works?

Do I need to choose other MCU due to 5V issue? what do you suggest?

​

Thanks.

Norzilah

[KiptonM]

Look at the data sheet to see what the LCD calls a logic high. A lot of times it is 2.7 volts or less. Since your logic high is greater than 3, it should work for writing to the LCD. If you have to read from the LCD you have to add some extra HW like a zener and a resistor, to keep the 5V from damaging your input pins.

If that does not work (which it should) you can always use the outputs as open collector, and pull up to 5V with a resistor. You still have problems if you have to read the LCD.

[waclawek.jan]

> So how do I need to drive my LCD with 5V voltage using L073?

You simply can't.

I'm afraid there are not many western semiconductor manufacturers producing LCD-equipped mcus, let alone 5V; or even LCD controllers - this kind of business mostly migrated to the Far East during the last decades.

JW