AN3114

LCD controller drive signals

Doc ID 16829 Rev 3

17/43

Discrimination ratio calculation for octaplex mode:

COM0 - SEG0 [ON] = (0 -VDD) + 3 (3VDD/4-VDD) + 2 (3VDD/4 - VDD/2) + 2 (3VDD/4 -

VDD) + (VDD - 0) + 3 (VDD/4 - 0) + 2 (VDD/4 - VDD/2) + 2 (VDD/4 - 0) => VDC = 0

COM0 - SEG0 [OFF] = 4 (3VDD/4-VDD) + 2 (3VDD/4 - VDD/2) + 2 (3VDD/4 - VDD) + 4

(VDD/4 - 0) + 2 (VDD/4 - VDD/2) + 2 (VDD/4 - 0) => VDC = 0

V

ON RMS

()

VSi

()

2

n

∑

n

------------------------

7

VDD

4

-------------

⎝⎠

⎛⎞

2

VDD

()

2

7

VDD

–

4

----------------

⎝⎠

⎛⎞

2

VDD

–

()

2

++

+

16

----------------------------------------------------------------------------------------------------------------------

0,423VDD

==

=

V

OFF RMS

()

VSi

()

2

n

∑

n

------------------------

8

VDD

4

-------------

⎝⎠

⎛⎞

2

8

VDD

–

4

----------------

⎝⎠

⎛⎞

2

+

16

------------------------------------------------------------

0,25VDD

==

=

D

V

ON RMS

()

V

OFF RMS

()

-----------------------------

0,423VDD

0,25VDD

----------------------------

1,692

==

=