KR20060104006A - Apparatus for recovering energy of driving devices of a plasma display panel - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an energy recovery apparatus for a plasma display panel driving circuit, and is used in an energy recovery (ER) circuit used for driving a plasma display panel (PDP) to suppress a reflux current. It is configured to be. Accordingly, the operating margin of the plasma display panel can be improved and the reliability of components can be improved.

PDP, sustain, energy recovery, reflux current

Description

Apparatus for recovering energy of driving devices of a Plasma Display Panel}

1 is an example of a conventional energy recovery device,

2 is an example of switching timing in an energy recovery apparatus;

3 is an embodiment of an energy recovery apparatus according to the present invention,

4 is a simulation result graph of the energy recovery device according to the present invention.

* Explanation of symbols for main parts of the drawings

Q1, Q2, Q3, Q4, Q11, Q12, Q13, Q14: Switch D1, D2, D3, D11, D12: Diode

L, L1, L2: Inductor Cp: Panel Capacitor

Cs: source capacitor 30: recovery current accumulating means

32: recovery current release means 34: current recovery means

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an energy recovery apparatus in a plasma display panel driving circuit. In particular, the present invention is used in an energy recovery (ER) circuit used to drive a plasma display panel (PDP) to suppress a reflux current. This is to improve the operating margin of the plasma display panel and to increase the reliability of the parts.

An energy recovery apparatus used to drive a conventional plasma display panel will be described with reference to FIG. 1.

Here, the panel capacitor Cp equivalently represents the capacitance formed between the scan electrode and the sustain electrode. A third switch Q3 and a fourth switch Q4 are connected in parallel to the source capacitor Cs, and an anode of the diode D1 is connected to the other end of the third switch Q3 and the diode D1 of the diode D1 is connected. The cathode is connected to the anode of another diode D2. The cathode of the diode D2 is again connected to the other end of the fourth switch Q4, and the inductor L is connected between the common node of the diode D1 and the diode D2 and the panel capacitor Cp. .

The current accumulated in the panel capacitor Cp is recovered and accumulated in the source capacitor Cs, and the third switch Q3 supplies the recovered current stored in the source capacitor Cs to the panel capacitor Cp again. The third switch Q3 is turned on by the Er_up signal that controls. Accordingly, a current path is formed from the source capacitor Cs to the third switch Q3, the inductor L, and the panel capacitor Cp, and the inductor L and the panel capacitor Cp form a series resonant circuit. By forming, the panel capacitor Cp can be charged with a voltage equal to the magnitude of the sustain voltage Vs.

When the fourth switch is turned on by the Er_dn signal controlling the fourth switch Q4 so that the current accumulated in the panel capacitor Cp is recovered and accumulated in the source capacitor Cs, the panel capacitor Cp is turned on. A current path from Cp to the inductor L, the fourth switch Q4, and the source capacitor Cs is formed so that the current accumulated in the panel capacitor Cp is recovered to the source capacitor Cs.

1, a first switch Q1 and a second switch Q2 are connected in parallel to a common node of the inductor L and the panel capacitor Cp, and the other end of the first switch Q1 is It is connected to the sustain voltage Vs, and the other end of the second switch Q2 is connected to the ground voltage source GND.

Therefore, when the first switch Q1 is turned on by the Sus_up signal for supplying the sustain voltage Vs to the panel capacitor Cp, the panel is charged with the voltage of the sustain voltage Vs size by the Er_up signal. The sustain voltage Vs is continuously supplied to the capacitor Cp to prevent the voltage of the panel capacitor Cp from falling below the sustain voltage Vs. This allows sustain discharge to occur normally.

After the current accumulated in the panel capacitor Cp is discharged by the Er_dn signal and recovered to the source capacitor Cs, the Sus_dn signal for controlling the second switch Q2 so that the residual voltage of the panel capacitor Cp becomes 0 volt. Occurs. Accordingly, when the second switch Q2 is turned on, a current path is formed from the panel capacitor Cp to the base voltage source GND, thereby lowering the voltage of the panel capacitor Cp to 0 volts.

The diode D3 has an anode connected to one end of the inductor L and a cathode connected to the sustain voltage Vs, and a diode D1 positioned between the third switch Q3 and the fourth switch Q4. The diode D2 and the internal diodes of the first switch Q1 to the fourth switch Q4 control the flow of current to prevent the current from flowing in the reverse direction.

As a result, referring to the operation of the conventional energy recovery device, the source capacitor Cs recovers and accumulates the accumulated current in the panel capacitor Cp during sustain discharge, and supplies the accumulated current to the panel capacitor Cp. Allow the voltage as much as the sustain voltage (Vs) to be charged.

An operation process of the energy recovery device shown in FIG. 1 will be described in detail through the voltage waveforms of the panel capacitor Cp according to the waveforms of the Er_up signal, the Er_dn signal, the Sus_up signal, and the Sus_dn signal shown in FIG. 2. .

Here, it is assumed that the panel capacitor Cp is charged with a voltage of 0 volts and the source capacitor Cs is charged with a half magnitude (Vs / 2) voltage of the sustain voltage before the T1 period.

In the T1 period, the third switch Q3 is turned on in response to the occurrence of the Er_up signal, and the current accumulated in the source capacitor Cs is supplied to the panel capacitor Cp. At this time, since the inductor L and the panel capacitor Cp form a series resonant circuit, the panel capacitor Cp is provided with a sustain voltage that is twice the voltage of the source capacitor Cs by supplying current from the source capacitor Cs. Vs) is charged.

In the T2 period, the first switch Q1 is turned on by the Er_dn signal, and the sustain voltage Vs is supplied to the panel capacitor Cp. This prevents the voltage of the panel capacitor Cp from dropping below the sustain voltage Vs. Since the voltage of the panel capacitor Cp has risen to the sustain voltage Vs during the T1 period, it is supplied externally to cause sustain discharge. Giving drive power is minimized.

The voltage of the panel capacitor Cp maintains the sustain voltage Vs for the period of T3. In the T4 period, the first switch Q1 is turned off and the fourth switch Q4 is turned on by the Sus_up signal. As a result, the current accumulated in the panel capacitor Cp is recovered to the source capacitor Cs, and the source capacitor Cs is charged with a voltage Vs / 2 of half the cysteine voltage.

In the T5 period, the fourth switch Q4 is turned off and the second switch Q2 is turned on by the Sus_dn signal. The second switch Q2 forms a current path between the panel capacitor Cp and the base voltage source GND to allow the voltage of the panel capacitor Cp to drop to zero volts.

In the T6 period, the state of T5 is maintained for a certain time.

The operation generated from T1 to T6 is periodically repeated.

On the other hand, in the period in which the sustain current is supplied through the first switch Q1, a reflux current is generated through the inductor L, as shown by a dotted line in FIG. 1. In this case, when the reflux current flows, devices positioned on the path through which the reflux current flows are subjected to stress, which may adversely affect the reliability of the circuit. In addition, a part of the current to be caused by the discharge falls into the reflux current through the inductor (L).

Accordingly, the present invention has been made to solve the above problems, it is possible to suppress the reflux current in the energy recovery device of the plasma display panel driving circuit, thereby improving the reliability of various components of the plasma display panel driving circuit. The goal is to improve the operating margin.

In order to achieve the above object, the energy recovery apparatus in the plasma display panel driving circuit according to the present invention is connected in series between the electrode of the panel which is a capacitive load and the sustain voltage, and is controlled by the Sus_up and Er_up signals, respectively. A first switch and a third switch for supplying current to the electrodes of the panel; A second switch and a fourth switch connected in series between an electrode of the panel and a ground voltage source, respectively controlled by a Sus_dn signal and an Er_dn signal to discharge current stored in the electrode of the panel; Current recovery means for recovering the current discharged through the fourth switch and accumulating it in the recovery current accumulating means; And recovery current emitting means for emitting current accumulated in the recovery current accumulating means to the electrode of the panel through the third switch.

In the energy recovery apparatus according to the present invention, the recovery current discharge means includes a first inductor; And first current flow control means for controlling the current flow so that the current accumulated in the recovery current accumulating means is discharged to the electrode of the panel through the first inductor and the third switch, and reverse current is blocked. And the current recovery means comprises: a second inductor; And second current flow control means for recovering current flowing through the fourth switch and the second inductor discharged from the electrode of the panel, and controlling the current flow to block reverse current.

Here, the first and second current flow control means is characterized in that the diode.

In addition, in the energy recovery apparatus according to the present invention, the first to fourth switches are characterized in that the switch configured using a MOS device.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Referring to FIG. 3, the energy recovery apparatus according to the present invention includes a recovery current accumulating means 30, a recovery current discharging means 32, and a current recovering means 34 between the three means and the panel capacitor Cp. The first switch Q11 and the third switch Q13 are arranged in series, and the fourth switch Q14 and the second switch Q12 are arranged in series.

At this time, the first switch Q11 and the third switch Q13 are connected in series between the sustain voltage Vs and the output node OUT, and the fourth switch Q14 and the second switch Q12 are output. It is connected in series between the node OUT and the ground voltage source GND.

In addition, each of the third switch Q13, the first switch Q11, the fourth switch Q14, and the second switch Q12 are controlled by the Er_up signal, the Sus_up signal, the Er_dn signal, and the Sus_dn signal, respectively.

As a result, the Er_up signal causes the current accumulated in the recovery current accumulating means 30 to be supplied to the panel capacitor Cp through the third switch Q13 through the recovery current discharging means 32 and to sustain the panel capacitor Cp. As much as the voltage Vs is charged, the Sus_up signal supplies the sustain voltage Vs to the panel capacitor Cp so that the voltage charged to the panel capacitor Cp through the Er_up signal is maintained.

After the sustain discharge occurs in the panel capacitor Cp, the Er_dn signal is generated and the current accumulated in the panel capacitor Cp is passed through the current recovery means 34 through the fourth switch Q14, and the recovery current accumulating means 30 ) And the Sus_dn signal initializes the panel capacitor Cp so that the voltage charged to the panel capacitor Cp becomes 0 volt.

That is, when the third switch Q13 is turned on by the Er_up signal, the current accumulated in the recovery current accumulating means 30 via the recovery current emitting means 32 is emitted to the panel capacitor Cp, and the Er_dn signal When the fourth switch Q4 is turned on, the current stored in the panel capacitor Cp is collected by the current collecting means 34 and collected by the current collecting means 30.

In the present invention, as the recovery current accumulating means 30, a source capacitor Cs capable of accumulating the current recovered from the panel capacitor Cp is used.

The recovery current discharging unit 32 discharges the first inductor and the current accumulated in the recovery current accumulating unit 30 to the panel capacitor Cp through the first inductor and the third switch, and reverse current is blocked. It may be configured as a first current flow control means for controlling the current flow as possible.

The current recovering means 34 recovers the current flowing through the fourth switch and the second inductor discharged from the second inductor and the panel capacitor Cp, and the second current controls the current flow so that reverse current is blocked. It may be configured as a flow control means.

Here, the first current flow control means of the recovery current discharge means 32 and the second current flow control means of the current recovery means 34 are characterized in that the diode.

Through the voltage waveform of the panel capacitor Cp according to the waveforms of the Er_up signal, the Er_dn signal, the Sus_up signal, and the Sus_dn signal shown in FIG. 2, the operation process of the energy recovery device shown in FIG. 3 will be described in more detail. do. At this time, it is assumed that the panel capacitor Cp is charged with a voltage of 0 volts and the source capacitor Cs is charged with a voltage (Vs / 2) half of the sustain voltage size before the T1 period.

In the T1 period, while the third switch Q13 is turned on by the generation of the Er_up signal, the current accumulated in the recovery current power storage means 30 is released through the recovery current discharge means 32 to the panel capacitor Cp. At this time, the first inductor L1 existing in the recovery current discharging means 32 forms a series resonant circuit with the panel capacitor Cp by supplying the current of the recovery current accumulating means to form the panel capacitor Cp. Is charged with a voltage of the sustain voltage Vs, which is twice the voltage charged in the source capacitor Cs.

In the T2 period, the first switch Q11 is turned on by the generation of the Sus_up signal. When the first switch Q11 is turned on, the sustain voltage Vs is supplied to the panel capacitor Cp, thereby preventing the voltage of the panel capacitor Cp from falling below the sustain voltage Vs. At this time, since the voltage of the panel capacitor Cp has risen to the sustain voltage Vs in the T1 period, the driving power supplied from the outside to cause the sustain discharge is minimized. Then, the voltage of the panel capacitor Cp maintains the sustain voltage Vs for the period of T3.

In the T4 period, the fourth switch Q14 is turned on by the Er_dn signal. Accordingly, the current recovery means 34 receives the current discharged from the panel capacitor Cp through the fourth switch Q14 and transfers it to the recovery current accumulating means 30, and the source capacitor serving as the recovery current accumulating means 30. As current accumulates in (Cs), a voltage that is half the size (Vs / 2) of the sustain voltage (Vs) is charged again.

In the T5 period, the second switch Q12 is turned on by the Sus_dn signal, thereby forming a current path between the panel capacitor Cp and the base voltage source GND and discharging the voltage of the panel capacitor Cp to 0 volts. To initialize the panel capacitor Cp.

In the T6 period, the state of the T5 period is maintained for a certain time. The operation generated from T1 to T6 is periodically repeated.

In the energy recovery device according to the present invention, the current flowing through the first switch Q11 is the first inductor L1 or the second inductor, which is an energy recovery coil by the first diode D11 and the fourth switch Q14. The flow to L2 is suppressed, thereby preventing the reflux current from flowing.

In each of the above-described embodiments, the first switch Q11 to the fourth switch Q14 may be preferably configured by using a MOS device.

4 is a simulation result of applying 200 volts as the sustain voltage to the circuit shown in FIG. 3, and it can be seen that the sustain output waveform has the same energy recovery resonance as the conventional energy recovery device shown in FIG. 1.

The present invention is not limited to the above embodiments and can be variously modified and implemented by those skilled in the art without departing from the technical spirit of the present invention.

According to the present invention, the reflux current can be suppressed in the energy recovery device of the plasma display panel driving circuit, thereby improving the reliability of various components of the plasma display panel driving circuit and improving the operating margin of the plasma display panel. .

Claims (5)

A first switch and a third switch connected in series between an electrode of the panel, which is a capacitive load, and a sustain voltage, respectively controlled by a Sus_up signal and an Er_up signal to supply current to the electrode of the panel; A second switch and a fourth switch connected in series between an electrode of the panel and a ground voltage source, respectively controlled by a Sus_dn signal and an Er_dn signal to discharge current stored in the electrode of the panel; Current recovery means for recovering the current discharged through the fourth switch and accumulating it in the recovery current accumulating means; And And a recovery current discharge means for releasing current accumulated in the recovery current accumulating means to the electrode of the panel through the third switch. The method of claim 1, wherein the recovery current discharge means A first inductor; And And first current flow control means for controlling the current flow so that the current accumulated in the recovery current accumulating means is discharged to the electrode of the panel through the first inductor and the third switch, and reverse current is blocked. An energy recovery apparatus in a plasma display panel drive circuit. The method of claim 1, wherein the current recovery means A second inductor; And And a second current flow control means for recovering current flowing through the fourth switch and the second inductor discharged from the electrode of the panel, and controlling the current flow so that reverse current is blocked. An energy recovery device in a drive circuit. The method of claim 2 or 3, wherein the first and second current flow control means An energy recovery device for a plasma display panel drive circuit, wherein the diode is a diode. The method of claim 1, wherein the first to fourth switches An energy recovery device for a plasma display panel drive circuit, comprising: a switch configured by using a MOS device.

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