Swing Power Supply For The Vertical Drive (V0Y) And Logic (Vccy / V5Y) Voltages - Epson S1D13706 Technical Manual

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2.4 Swing Power Supply for the Vertical Drive (V0Y) and Logic (VCCY / V5Y)

Power Supply Potential V0Y

Power Supply Potential VCCY

Power Supply Potential V5Y

X31B-G-012-03

The vertical drive voltage (V0Y) and vertical logic voltages (VCCY and V5Y) require a

swing power supply. To obtain the required voltage range, VEEY is used to swing the

vertical system voltages through the recommended -32V to 32V range. The swing circuit

is shown in Figure 2-5: "Swing Power Supply for Vertical System Voltages" .

Figure 2-5: Swing Power Supply for Vertical System Voltages

The swing power supply is controlled by the S1D13706 output signal GPIO3 (FRS). When

GPIO3 is low, transistor Q1B turns on and Q1A turns off. V5Y (vertical logic low

potential) goes to GND. Transistor U1 also turns on and VCCY (vertical logic high

potential) = VCC = 3.3V. V0Y (vertical liquid crystal drive supply) swings to | VEEY | +

4.5 when GPIO3 goes low since the reference changes to VEEY from GND for this signal.

When GPIO3 is high, transistor Q1A turns on and Q1b turns off. V5Y goes to the level of

VEEY. VCCY is now referenced to VEEY and its level goes to VEEY + VCC. Diode D8

forward biases and sets V0Y = VDDH = 4.5V.

The following table shows the values of V5Y, V0Y, and VCCY for the high and low values

of the control signal GPIO3 (FRS).

Table 2-1: Swing Power Supply Values

|VEEY| + VDDH

Epson Research and Development

Vancouver Design Center

Connecting to the Epson D-TFD Panels

Issue Date: 01/02/23

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