MSP430 LCD_E 1/2 BIAS

Eduardo Bernardi

Other Parts Discussed in Thread: MSP430FR4133

According to family guide, the msp430fr4133 that i am using does not support 1/2 bias lcd mode, only 1/3. The display samples that i am working with are 1/2 bias. Is there anything i can do instead of requesting another kind of display? I also got the VIM878 display from digikey for test purposes, but there is no information about the biasing on its datasheet. Any suggestions?

over 9 years ago

0 Ryan Brown1 over 9 years ago

TI__Guru**** 217837 points

Eduardo,

Are you sure that the display you are working with only supports 1/2 bias (a mux ratio of 1/2)? Can it not be used with any other mux ratio? Please provide the LCD name and datasheet. The VIM878 datasheet does not contain much information but it seems to me like it can be used at multiple mux ratios (1/2 or 1/3 included).

Regards,
Ryan

0 Eduardo Bernardi over 9 years ago in reply to Ryan Brown1

Intellectual 920 points

I attached the AD8077 datasheet.

I did not find the VIM878 specifications. I made the pcb layout with it, it is a prototype for "concept validating" for this product so any glass lcd like vim878 will fit.

Do you think it is to risky if I use the vim878 in 1/3 bias mode?

AD8077.pdf

0 Ryan Brown1 over 9 years ago in reply to Eduardo Bernardi

TI__Guru**** 217837 points

It would appear that the AD8077 is designed only for 1/2 bias and therefore would not be compatible with the MSP430FR4311. The VIM878 seems very similar in operation to the PD-878 which can be driven under multiple biases: www.pacificdisplay.com/.../PD-878.pdf

This would leave me to believe that you can drive the VIM878 in 1/3 bias mode, but to be certain you would probably have to contact the manufacturer. Varitronix's contact information can be found on their website.

Regards,
Ryan

0 Eduardo Bernardi over 9 years ago in reply to Ryan Brown1

Intellectual 920 points

I tried to contact varitronix, but i didnt receive any reply. I will keep the vim878 on my layout, worst case scenario i change it to PD-878, since they are pin to pin compatible. Thanks for you support !

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MSP430 LCD_E 1/2 BIAS