CN1258880C - Level shifting grid voltage control circuit having thin grid oxygen low power comsumption self restored - Google Patents

Abstract

The present invention relates to a level shifting grid voltage control circuit with the function of thin grid oxygen low power consumption automatic restoration, which belongs to the technical field of level shifting grid voltage control. The present invention is characterized in that the present invention is composed of a sensitive amplifying circuit known publicly, a high voltage level shifting circuit, a driving output stage and a driving closing output stage which are known publicly, a constant current source and a control circuit of the driving and the driving closing output stages, wherein after grid electrodes and drain electrodes of tubes P1, P2 in the high voltage level shifting circuit are connected, and the grid electrodes and the drain electrodes are respectively connected with the drain electrodes of tubes HP1, HP2 in the sensitive amplifying circuit. HN2 in the sensitive amplifying circuit is used as the constant current source of which the grid electrode is controlled by an inverter, a constant current power supply branch and a circuit, wherein the input signals of the inverter are used as system control signals; the constant current power supply branch which composed of a P tube and an N tube which are butted mutually is connected in series between a control power supply and the ground, and the grid electrodes of the constant current power supply branch are all connected with the output of the inverter; the circuit is composed of another N tube connected in parallel with the N tube. The present invention has the advantages of low power consumption and automatic restoration.

Description

The self-healing level shift gate voltage of the low-power consumption of thin gate oxide control circuit

Technical field:

The self-healing level shift gate voltage of the low-power consumption of thin gate oxide control circuit belongs to the level shift gate voltage of high tension apparatus, relates in particular to the level shift circuit field in Organic Light Emitting Diode OLED (Organic Light Emission Diode) black and white, the colorful display screen.

Background technology:

Existing typical level shift circuit as shown in Figure 1.

In the empty frame is the regeneration level walking circuit.Frame is outward the high-voltage power output stage, operating voltage 30V, drive current 150mA.Except that inverter for the low pressure 5V work, all the other N, P pipe all is operated in high pressure 30V.Wherein N pipe grid voltage is provided by the low voltage logic circuit.Logic level is generally 4.3-5V.P pipe grid are high pressure (30V).

For preventing that the too high grid that cause of P pipe grid voltage from puncturing, a kind of way is to increase gate oxide thickness to more than 500 , and different with the gate oxide thickness (100 ) of other low-voltage devices, this will increase the manufacturing process difficulty, increase cost.

Level shift circuit after the improvement as shown in Figure 2.In the empty frame is the basic displacement circuit, adopts the current mirror working method.Increase a constant-current source and a current mirror, be T ₄The pipe grid electric charge of releasing.Shortcoming is at V _IN=1 changes V into _IN=0 o'clock, T ₂, T ₄Manage residual 0.5V grid voltage, can be at T ₁Form transient current during the pipe conducting, cause power loss.T ₅, T ₆Pipe is in order to eliminate above-mentioned shortcoming, but at V _INDuring the work of=1 normality, T ₃, T ₅, T ₆Electric current in the pipe will cause waste of electric energy.

Fig. 3 is for power consumption that overcomes above two kinds of shortcomings and cause because of subthreshold current and the unstable improved circuit that designs.Characteristics are as follows:

A. increase gating signal V _PASSControl T ₃, T ₅ON time is T ₂The pipe charging.After the complete charge, with charge storage at T ₂Gate capacitance on.Can reduce T like this ₃, T ₅ON time reduces power consumption.

B. use gating signal V _PASSControl T ₁₄, T ₁₅Be the T2 tube discharge, prevent that short circuit current from appearring in output stage.

C., power consumption only when existing, gating signal is just arranged.

But there is following shortcoming in the circuit of Fig. 3:

1. level shift mainly adopts current mirroring circuit.Sort circuit is fit to be applied to linear circuit, makees switch and uses then existence obviously not enough, because it is difficult to turn-off fully.Be breaking circuit, need to add many devices and make circuit become complicated.

2. owing to the circuit complexity, problems such as linear work also because phase shift and time unlatching are leaked electricity, are difficult to synchronously circuit, and the working point is difficult to control, and reliability reduces.

3. the two-phase signal controlling increases support circuit, makes complex system, increases production cost.

Summary of the invention:

The object of the present invention is to provide one can overcome above-mentioned shortcoming, be used for the high-pressure level shift circuit of OLED drive circuit.

The invention is characterized in:

1. the self-healing level shift gate voltage of the low-power consumption of thin gate oxide control circuit is characterized in that it contains

(1). sensitive amplifier circuit: it is by high voltage PMOS pipe HP ₁, HP ₂With high pressure NMOS pipe HN ₁, HN ₂Form HP ₁HP ₂Source electrode all link to each other HN with the power supply high-pressure side ₁, HN ₂Source electrode altogether, HP ₁, HP ₂Grid separately respectively with HP ₂, HP ₁Drain electrode link to each other, wherein, HN ₂It is the constant-current source of one 20～50 μ A;

(2). the high-pressure level shift circuit shift circuit: it is by P ₂, P ₃Pipe is formed, P ₂, P ₃Source electrode all link to each other P with the power supply high-pressure side ₂, P ₃Pipe grid and drain electrode separately links to each other, and then distinguishes successively and HP ₂, HP ₁The drain electrode of pipe links to each other;

(3). drive and turn-off the driving output stage: by PMOS pipe HP ₃With NMOS pipe HN ₃Drain electrode is connected to form; HP ₃Source electrode link to each other HP with the high-pressure side of power supply ₃Grid and HN ₂Drain electrode link to each other HN ₃Source ground;

(4). constant-current source HN ₂, and the control circuit that drives and close the driving output stage: it is by inverter, P ₁Pipe, N ₁Pipe, N ₂Pipe, HN ₂Pipe is formed, wherein, and P ₁The drain electrode of pipe and N ₁The drain electrode of pipe links to each other, P ₁Source electrode, connect the high-pressure side of constant current control power supply, N ₁, N ₂The source ground of pipe, N ₂After the drain electrode of pipe and its gate interconnect, respectively with P ₁The drain electrode of pipe, HN ₂The gate interconnect of pipe, the input welding system control signal In of inverter, output termination P ₁Pipe, N ₁The grid of pipe, thereby inverter, P ₁Pipe, N ₁Pipe, N ₂It is 20～50 μ A constant-current source HN that pipe has been formed electric current jointly ₂Control circuit; The output of inverter meets above-mentioned efferent duct HN ₃Grid, and HN ₃The drain electrode of pipe and HP ₃The drain electrode of pipe links to each other, and makes inverter and HN ₃Pipe has been formed the control circuit that drives and close the driving output stage again jointly.

Experimental results show that: circuit of the present invention can guarantee the N pipe of complementary drive level and P manage grid source driving voltage be respectively 0～5V and 0～-5V.See accompanying drawing.

Description of drawings:

Fig. 1. existing typical electrical translational shifting circuit theory diagrams, wherein, HVN refers to high pressure NDMOS pipe; HVP refers to high pressure P DMOS pipe.

Refer to the low pressure inverter, down together.

Fig. 2. the schematic diagram of the improvement circuit of the described circuit of Fig. 1.

Fig. 3. be the described improvement circuit theory diagrams of Fig. 2, wherein, T15 is a current mirror, is the LDD high voltage PMOS device; Refer to and door.

Fig. 4. be the schematic diagram of clamping type level shift circuit.

Fig. 5. be the schematic diagram of current mirror level shift circuit.

Fig. 6. be used for to the described circuit of Fig. 4, Fig. 5 lower consumption the design constant-current control circuit.

Fig. 7. be the self-healing level shift gate voltage of the low-power consumption control circuit schematic diagram of thin gate oxide of the present invention.

Embodiment:

With standard 0.5 μ m CMOS process compatible, all adopt same thin gate oxide in the height pressure pipe, under the situation of thickness 100 , present patent application provides following technical scheme:

1). simplify the high-pressure level shift circuit design

Fig. 4, Fig. 5 are the simplified design of a level shift circuit.It is by high voltage PMOS pipe HP ₁, HP ₂With high pressure NMOS pipe HN ₁, HN ₂Form sense amplifier, drive and close driving output stage PMOS pipe HP ₃, HN ₃" In " controls by system control signal.

P in the frame of broken lines ₂, P ₃The effect of pipe is with the high voltage level displacement, makes high-voltage tube HP ₁And HP ₂Gate source voltage be 0～-5V.P among Fig. 4 ₂, P ₃Equivalence is a backward diode, and punch through voltage-5V is leaked in the source.P among Fig. 5 ₂, P ₃And HP ₁, HP ₂Form current mirror, make HP ₁, HP ₂Acquisition-5V gate source voltage.

When control signal In=" 1 ", HN ₂, HP ₃Conducting is charged to the demonstration load by HP3, simultaneously, and HP ₁Conducting is HP ₂The gate capacitance discharge makes HP ₂Close.When control signal In=" 0 ", HN ₂Close, HP ₂Conducting makes HP ₁, HP ₃Close, finish charge cycle.

Like this, in one-period, this circuit can be finished level shift, can automatically reset again, and need not increase any reset device and circuit.

Each row of display screen, corresponding one group of drive circuit.If the line number of every frame is 100 row, the addressing pulse duty factor is 1: 1, and selected and ratio free time of then every row is 1: 200.Free time HN ₂Conducting, load are P ₂Pipe, and pass through HP ₃To showing the load charging.HN as a result ₂, P ₂In electric current cause main power loss.

The circuit of Fig. 6 is when control signal In=1, makes HN ₂Become the constant-current source of a 20-50 μ A,, can satisfy charging requirement, can reduce electric energy loss again because idle periods is long.

2). Fig. 7 is the self-healing level shift gate voltage of the low-power consumption of an a complete thin gate oxide of the present invention control circuit.It is used for the control of OLED display driver.

Adopt circuit of the present invention,, when design layout, it is embedded between display logic circuit and the power driving circuit, also can make independently level shift circuit according to different technology conditions and design rule.

Manufacturing process of the present invention and standard 0.5 μ m CMOS process compatible.High tension apparatus wherein, when OLED used, its operating voltage was 12V～30V.According to circumstances, select LDD or DMOS structure, the both has ripe, with the compatible technology of standard 0.5 μ m CMOS.

Circuit of the present invention when choice criteria 0.5 μ m CMOS-DMOS compatible technology, is selected suitable DMOS structure, can be operated under the higher voltage, in 100V, or higher, can be applicable to plasma panel (PDP), liquid crystal display (LCD) waits other display driver circuits.

A kind of embodiment of practicality:

Employing standard 0.5 μ m CMOS and DMOS compatible technology, the gate oxide of all devices is 100 .No matter high pressure and low pressure, the cut-in voltage of NMOS, PMOS pipe is respectively ± 0.7V.Low-voltage tube operating voltage 5V, high-voltage tube 20V.The input signal inverter uses standard 0.5 μ m technology.W is a channel width, and L is a channel length, unit micron (μ m).

The electrical quantity table:

The parameter symbol	Character	Metering	Circuit function
				I A	Electric current	106μA	Current mirror
I B	Electric current	50μA	Current mirror
				I C	Electric current	2.87mA	Current mirror
V G1	Voltage	0～5V	The HP1 gate voltage
				V G2	Voltage	0～5V	The HP2 gate voltage

The advantage of circuit of the present invention

Compare this circuit because electric current I with available circuit_CLarge and driving force is strong, reduce soon and greatly the leakage current that subthreshold voltage and the simultaneously conducting of P, N pipe cause from resume speed, reduce the measure such as idle current and reduced circuit power consumption, simplified circuit design.

Claims (1)

1. the self-healing level shift gate voltage of the low-power consumption of thin gate oxide control circuit is characterized in that it contains

(1). sensitive amplifier circuit: it is by high voltage PMOS pipe HP ₁, HP ₂With high pressure NMOS pipe HN ₁, HN ₂Form HP ₁HP ₂Source electrode all link to each other HN with the power supply high-pressure side ₁, HN ₂Source electrode altogether, HP ₁, HP ₂Grid separately respectively with HP ₂, HP ₁Drain electrode link to each other, wherein, HN ₂It is the constant-current source of one 20～50 μ A;

(2). the high-pressure level shift circuit shift circuit: it is by P ₂, P ₃Pipe is formed, P ₂, P ₃Source electrode all link to each other P with the power supply high-pressure side ₂, P ₃Pipe grid and drain electrode separately links to each other, and then distinguishes successively and HP ₂, HP ₁The drain electrode of pipe links to each other;

(3). drive and turn-off the driving output stage: by PMOS pipe HP ₃With NMOS pipe HN ₃Drain electrode is connected to form; HP ₃Source electrode link to each other HP with the high-pressure side of power supply ₃Grid and HN ₂Drain electrode link to each other HN ₃Source ground;

(4). constant-current source HN ₂, and the control circuit that drives and close the driving output stage: it is by inverter, P ₁Pipe, N ₁Pipe, N ₂Pipe, HN ₂Pipe is formed, wherein, and P ₁The drain electrode of pipe and N ₁The drain electrode of pipe links to each other, P ₁Source electrode, connect the high-pressure side of constant current control power supply, N ₁, N ₂The source ground of pipe, N ₂After the drain electrode of pipe and its gate interconnect, respectively with P ₁The drain electrode of pipe, HN ₂The gate interconnect of pipe, the input welding system control signal In of inverter, output termination P ₁Pipe, N ₁The grid of pipe, thereby inverter, P ₁Pipe, N ₁Pipe, N ₂It is 20～50 μ A constant-current source HN that pipe has been formed electric current jointly ₂Control circuit; The output of inverter meets above-mentioned efferent duct HN ₃Grid, and HN ₃The drain electrode of pipe and HP ₃The drain electrode of pipe links to each other, and makes inverter and HN ₃Pipe has been formed the control circuit that drives and close the driving output stage again jointly.

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