Questions? Call us: +1 760-918-6722

S128240C refresh

How driver ST7529 will refresh the LCD S128240C FC BW-3.

According to frame frequency it is given the range of 78hz to 160hz, frame frequency frame rate was they are same if it is so the frame rate is 78/160 times in a second

I need to know how it is done internally by ST7529

In the page 40/86 ST7529 document it is given PB3 specifies number of line cycles (range from 2 to 16) in a frame what does it mean

According to LCD datasheet it is given that the duty ratio is 144 and bias as 1/12, in our LCD we have only 128 commons then why we need to use duty as 144.


dtechsupport's picture
July 19, 2011

1) After the driver DDRAM updated, the driver will update the signal waveform to update the LCD.
2) About the frame frequency, please refer to the IC data sheet command section, PBI setting of the Analog circuit set (32H).
3) Please refer to 7.8 Display timing generator circuit and 7.9 Liquid crystal drive circuit of the IC data sheet.
4) It means FI decides the inversion type of frame at the end of common scan cycle while the number of duty is not divisible by the number of line cycles per frame. For example, in the application of 1/m duty and n line cycles in a frame set, the difference of the choice in FI is shown as:
m = n x k + r, where m, n, k, and r are all whole numbers, and r is the remainder of m divided by n (r < n).
5) Duty of 144 was suggested by the IC manufacturer.