AN3114

LCD controller drive signals

Doc ID 16829 Rev 3

11/43

Figure 5.

LCD signals for duplex mode

Discrimination ratio calculation for duplex mode:

COM0 - SEG0 [ON] = (0 - VDD) + (VDD/2 - VDD) + (VDD - 0) + (VDD/2 - 0) => VDC = 0

COM0 - SEG0 [OFF] = (0 - 0) - (VDD/2 - VDD) + (0 - 0) + (VDD/2 - 0) => VDC = 0

COM0

MS19738V1

SEG0

SEG1

VDD/2

COM1

0 V

VDD

VDD/2

0 V

VDD

0 V

VDD

0 V

VDD

COM0-SEG0

Selected waveform

VDD/2

0 V

VDD

-VDD/2

-VDD

Odd

frame

Even

frame

Odd

frame

Even

frame

Odd

frame

V

ON RMS

()

VSi

()

2

n

∑

n

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

VDD

()

2

VDD

2

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

⎝⎠

⎛⎞

2

VDD

–

2

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

⎝⎠

⎛⎞

2

VDD

–

()

2

++

+

⎝⎠

⎛⎞

4

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

0,790VDD

==

=

V

OFF RMS

()

VSi

()

2

n

∑

n

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

0

()

2

VDD

2

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

⎝⎠

⎛⎞

2

0

()

2

VDD

–

2

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

⎝⎠

⎛⎞

2

++

+

⎝⎠

⎛⎞

4

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

0,353VDD

==

=

D

V

ON RMS

()

V

OFF RMS

()

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

0,790VDD

0,353VDD

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

2,237

==

=