Buffered Lcd Connector; Adjustable Lcd Panel Positive Power Supply (Vddh); Manual/Software Adjustable Lcd Panel Negative Power Supply (Vlcd) - Epson S1D13504 Technical Manual

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4.3.2 Buffered LCD Connector

4.3.3 Adjustable LCD Panel Positive Power Supply (VDDH)

S1D13504 Output Signal

4.3.4 Manual/Software Adjustable LCD Panel Negative Power Supply (VLCD)

S1D13504 Output Signal
S1D13504
X19A-G-014-01
J1 provides the same LCD panel signals as those directly from S1D13504, but with voltage-
adapting buffers which can be set to 3.3V or 5V. Pin 32 on this connector provides power
for the LCD panel logic at the same voltage as the buffer power supply.
Most passive LCD color and passive single monochrome LCD panels require a positive
bias voltage between +24V and +40V. The S5U13504B00C uses a Maxim MAX754 LCD
Contrast Controller to provide this voltage range. VDDH can be adjusted using RV1 (200Ω
potentiometer) to provide an output voltage from +24V to +40V.
To enable the VDDH power supply, the evaluation board uses the LCDPWR# output from
the S1D13504, inverted by U6, to control the MAX754 as shown in the following table..
Table 4-5: Controlling the MAX754
LCDPWR#
Note
When manually adjusting the voltage, set the potentiometer according to the panel's
specific power requirements before connecting the panel.
Most passive monochrome LCD panels require a negative bias voltage between -14V and
-24V. The S5U13504B00C uses a Maxim MAX749 Digitally Adjustable LCD Bias Supply
to provide this voltage range. VLCD can be adjusted using RV2 (500K potentiometer) to
provide an output voltage from -16V to -23V.
To enable the VLCD power supply, the evaluation board uses the LCDPWR# output from
the S1D13504, inverted by U6, to control the MAX749 as shown in the following table..
Table 4-6: Controlling the MAX749
LCDPWR#
Note
When using manual adjust, set the potentiometer according to the panel's specific power
requirements before connecting the panel.
Turn MAX754 On
low
Turn MAX749 On
low
S5U13504B00C Rev. 2.0 PCI Evaluation Board User Manual
Epson Research and Development
Vancouver Design Center
Turn MAX754 Off
high
Turn MAX749 Off
high
Issue Date: 2002/12/02