AN2503

PDP Sustain circuit

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Figure 10.

Subfield structure – expression of gray level

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PDP Sustain circuit

In a Plasma Display Panel, frequent discharges are made to occur by alternately charging

each side of the panel to a critical voltage, allowing images to be displayed. This alternating

voltage is called the sustain voltage, and the sustain circuit (or sustainer) is needed to

provide it to the display [5.].

If a pixel has been driven "ON" during address period, the sustainer maintains the "ON"

state of that pixel by repeatedly discharging that pixel cell during the whole sustain period. If

a pixel has been driven "OFF" by an address driver, the voltage across the cell is never high

enough to cause a discharge, and the cell remains "OFF" during the sustain period.

The sustain circuit must drive all panel pixels at once. This means that the capacitance as

seen by the sustainer is typically very large. In a 42-inch panel with 852x480 pixels, the total

capacitance of all the pixel cells, Cp, could be as much as 80 nF.

The key parameters in the sustainer study are:

●

Cp - Panel equivalent capacitance

●

Vs - Sustain Voltage

●

f - Sustainer Switching frequency

●

Conventional sustain circuit (half bridge topology) drives the panel directly, and thus

ground.

In a complete sustain cycle, each side of the panel is charged to Vs and subsequently

sustain cycle.