
Epson Research and Development
Page 21
Vancouver Design Center
S5U13706B00C Rev. 1.0 Evaluation Board User Manual
S1D13706
Issue Date: 01/02/23
X31B-G-004-04
The S5U13706B00C uses GPO and CVOUT to control the MAX754 as shown in the
following table..
When JP5 is set to position 2-3, VDDH is adjustable using R24 (200
Ω
potentiometer) to
provide an output voltage from +24V to +40V.
Note
When manually adjusting the voltage, set the potentiometer according to the panel’s
specific power requirements before connecting the panel.
6.5 Manual/Software Adjustable LCD Panel Negative Power Supply (VLCD)
Most passive monochrome LCD panels require a negative bias voltage between -14V and
-24V. The S5U13706B00C uses a Maxim MAX749 Digitally Adjustable LCD Bias Supply
to provide this voltage range. The signal VLCD can be adjusted manually (using a potenti-
ometer) or controlled through software.
When JP7 is set to position 1-2, VLCD can be controlled through software to provide an
output voltage from -8V to -24V. CVOUT and GPO of the S1D13706 are connected to ADJ
and CTRL of MAX749. The output voltage (VLCD) can be adjusted from -8V to -24V in
64 steps by sending pulses to CVOUT. Each CVOUT pulse increments VLCD one step
towards -24V. When decremented beyond -24V, VLCD resets to -8V again. In other words,
63 pulses equal incrementing 1 step. After the MAX749 is reset (see “Controlling the
MAX749” on page 21), VLCD is set at -16V.
The S5U13706B00C uses GPO and CVOUT to control the MAX749 as shown in the
following table..
When jumper JP7 is set to position 2-3, VLCD can be adjusted by R41 (500K potenti-
ometer) to provide an output voltage from -16V to -23V.
Note
When using manual adjust, set the potentiometer according to the panel’s specific power
requirements before connecting the panel.
Table 6-1: Controlling the MAX754
Signal
Turn MAX754 On
Turn MAX754 Off
Reset MAX754
GPO
high
low
low
CVOUT
X
low
high
X = don’t care
Table 6-2: Controlling the MAX749
Signal
Turn MAX749 On
Turn MAX749 Off
Reset MAX749
GPO
high
low
low
CVOUT
X
low
high
X = don’t care