阅读说明：本技术 数字模拟转换器电路及其运作方法 (Digital-to-analog converter circuits and its operation method ) 是由 王暐筑 黄智全 于 2018-06-13 设计创作，主要内容包括：本发明公开了一种数字模拟转换器电路及其运作方法,应用于源极驱动装置。数字模拟转换器电路包含多个P型晶体管开关、多个N型晶体管开关及基板电压控制单元。该多个P型晶体管开关彼此串接。该多个N型晶体管开关彼此串接。基板电压控制单元分别耦接该多个P型晶体管开关的基板与该多个N型晶体管开关的基板,用以控制该多个P型晶体管开关的基板具有第一基板电压且该多个N型晶体管开关的基板具有第二基板电压。第一基板电压为工作电压减去特定电压差且第二基板电压为接地电压加上特定电压差。工作电压高于接地电压。(The invention discloses a kind of digital-to-analog converter circuits and its operation methods, are applied to source electrode driving device.Digital-to-analog converter circuits include multiple P-type transistors switch, multiple N-type transistors switch and substrate voltage control unit.Multiple P-type transistor switch is concatenated with one another.Multiple N-type transistor switch is concatenated with one another.Substrate voltage control unit is respectively coupled to the substrate of multiple P-type transistor switch and the substrate of multiple N-type transistor switch, and the substrate to control the substrate of multiple P-type transistor switch with first substrate voltage and multiple N-type transistor switchs has the second substrate voltage.First substrate voltage is that operating voltage subtracts particular voltage difference and the second substrate voltage is ground voltage plus particular voltage difference.Operating voltage is higher than ground voltage.)

1. a kind of digital-to-analog converter circuits are applied to a source electrode driving device, which is characterized in that the digital analog converter Circuit includes:

Multiple P-type transistor switches, multiple P-type transistor switch are concatenated with one another；

Multiple N-type transistor switches, multiple N-type transistor switch are concatenated with one another；And

One substrate voltage control unit, the substrate and multiple N-type transistor for being respectively coupled to multiple P-type transistor switch switch Substrate, the substrate to control multiple P-type transistor switch has a first substrate voltage and multiple N-type transistor is opened The substrate of pass has a second substrate voltage；

Wherein, which is that an operating voltage subtracts a particular voltage difference and the second substrate voltage is ground connection electricity Pressure adds the particular voltage difference, which is higher than the ground voltage.

2. digital-to-analog converter circuits according to claim 1, which is characterized in that the substrate voltage control unit according to Multiple P-type transistor switch determines the size of the particular voltage difference with the element characteristic of multiple N-type transistor switch, with drop The start-up resistor and critical voltage of those low transistor switches simultaneously avoid generating situation about leading to along local derviation.

3. digital-to-analog converter circuits according to claim 1, which is characterized in that if multiple P-type transistor switchs Source electrode receive one first input data signal and there is one first source voltage, then multiple P-type transistor switch this Voltage difference between source voltage and the first substrate voltage is less than the electricity between first source voltage and the operating voltage Pressure difference.

4. digital-to-analog converter circuits according to claim 3, which is characterized in that the first input data signal has The voltage for approaching the half of the operating voltage causes first source voltage to approach the half of the operating voltage.

5. digital-to-analog converter circuits according to claim 3, which is characterized in that the first input data signal has The voltage for approaching the operating voltage, causes that first source voltage approaches the operating voltage and the particular voltage difference levels off to zero.

6. digital-to-analog converter circuits according to claim 1, which is characterized in that if multiple N-type transistor switchs Source electrode receive one second input data signal and there is one second source voltage, then multiple N-type transistor switch this Voltage difference between two source voltages and the second substrate voltage is less than the electricity between second source voltage and the ground voltage Pressure difference.

7. digital-to-analog converter circuits according to claim 6, which is characterized in that the second input data signal has The voltage for approaching the half of the operating voltage causes second source voltage to approach the half of the operating voltage.

8. digital-to-analog converter circuits according to claim 6, which is characterized in that the second input data signal has The voltage for approaching the ground voltage, causes that second source voltage approaches the ground voltage and the particular voltage difference levels off to zero.

9. digital-to-analog converter circuits according to claim 1, which is characterized in that the source electrode driving device also includes one Operational amplifier and the operational amplifier have a first input end, one second input terminal and an output end, the operational amplifier The first input end be coupled to each other with the output end.

10. digital-to-analog converter circuits according to claim 9, which is characterized in that multiple p-type concatenated with one another is brilliant One end of body pipe switch is coupled to second input terminal of the operational amplifier.

11. digital-to-analog converter circuits according to claim 10, which is characterized in that the source electrode driving device also includes One divider resistance string, and the divider resistance string includes multiple divider resistances concatenated with one another, multiple P-type crystal concatenated with one another The other end of pipe switch is coupled between one end or any two adjacent divider resistances of the divider resistance string, to receive one first Input data signal.

12. digital-to-analog converter circuits according to claim 9, which is characterized in that multiple N-type concatenated with one another is brilliant One end of body pipe switch is coupled to second input terminal of the operational amplifier.

13. digital-to-analog converter circuits according to claim 12, which is characterized in that the source electrode driving device also includes One divider resistance string, and the divider resistance string includes multiple divider resistances concatenated with one another, multiple N-type crystal concatenated with one another The other end of pipe switch is coupled between one end or any two adjacent divider resistances of the divider resistance string, to receive one second Input data signal.

14. a kind of digital-to-analog converter circuits operation method turns to operate the digital simulation in a source electrode driving device Converter circuit, which is characterized in that the digital-to-analog converter circuits include that multiple P-type transistors switch, multiple N-type transistors are opened It closes and a substrate voltage control unit, multiple P-type transistor switchs concatenated with one another and multiple N-type transistor switch and go here and there each other It connects, which is respectively coupled to the substrate and multiple N-type transistor switch of multiple P-type transistor switch Substrate, the digital-to-analog converter circuits operation method comprise the steps of

(a) particular voltage difference is determined；

(b) operating voltage particular voltage difference is subtracted to obtain a first substrate voltage and control multiple P-type transistor opening The substrate of pass has the first substrate voltage；And

(c) ground voltage is obtained a second substrate voltage and controls multiple N-type transistor to open plus the particular voltage difference The substrate of pass has the second substrate voltage, and wherein the operating voltage is higher than the ground voltage.

15. digital-to-analog converter circuits operation method according to claim 14, which is characterized in that step (a) basis Multiple P-type transistor switch determines the size of the particular voltage difference with the element characteristic of multiple N-type transistor switch, with drop The start-up resistor and critical voltage of those low transistor switches simultaneously avoid generating situation about leading to along local derviation.

16. digital-to-analog converter circuits operation method according to claim 14, which is characterized in that if multiple p-type The source electrode of transistor switch receives one first input data signal and has one first source voltage, then multiple P-type transistor Voltage difference between first source voltage and the first substrate voltage of switch is less than first source voltage and work electricity Voltage difference between pressure.

17. digital-to-analog converter circuits operation method according to claim 16, which is characterized in that the first input number It is believed that number voltage with the half for approaching the operating voltage, causes first source voltage to approach the half of the operating voltage.

18. digital-to-analog converter circuits operation method according to claim 16, which is characterized in that the first input number It is believed that number voltage with the approach operating voltage, causes first source voltage to approach the operating voltage and the particular voltage difference Level off to zero.

19. digital-to-analog converter circuits operation method according to claim 14, which is characterized in that if multiple N-type The source electrode of transistor switch receives one second input data signal and has one second source voltage, then multiple N-type transistor Voltage difference between second source voltage and the second substrate voltage of switch is less than second source voltage and ground connection electricity Voltage difference between pressure.

20. digital-to-analog converter circuits operation method according to claim 19, which is characterized in that the second input number It is believed that number voltage with the half for approaching the operating voltage, causes second source voltage to approach the half of the operating voltage.

21. digital-to-analog converter circuits operation method according to claim 19, which is characterized in that the second input number It is believed that number voltage with the approach ground voltage, causes second source voltage to approach the ground voltage and the particular voltage difference Level off to zero.

Technical field

The present invention is related with display device, especially with respect to a kind of digital simulation applied in display driving integrated circuit Converter circuit and its operation method.

Background technique

Since the liquid crystal display panel of high-res (such as 4K or 8K) is gradually popularized, so that on face plate manufacturing technology Face the more and more stringent problem of specification requirement.

In general, as illustrated in figures 1A and ib, the connection of common digital-to-analog converter circuits is will be concatenated with one another The substrate of multiple P-type transistor switch MP0~MP7 be coupled to operating voltage AVDD or by multiple N-type crystal concatenated with one another The substrate of pipe switch MN0~MN7 is coupled to ground voltage AGND.

However, as shown in Fig. 2, divider resistance string RS can provide different voltage level VGM10~VGM18 and via conduct Digital analog converter DAC0~DAC255 of switch provides the channel operation amplifier OP of input signal SIN to rear end.Work as number When word analog converter DAC0~DAC255 transmits different voltages level, the cross-pressure between the source electrode and substrate of transistor switch 0 can be greater than, and it is inverse inclined to generate the substrate of transistor switch and source electrode, its critical voltage is caused to increase and generate not of uniform size Substrate effect, and then the resistance value of the conducting resistance (On-resistance, Ron) of transistor switch is influenced, cause digital simulation to turn The reaction speed of parallel operation DAC0~DAC255 is slack-off, also related so that channel operation amplifier OP provides output signal SOUT to liquid The charging time of crystal panel charging is influenced by input signal SIN.

Since the connection of common digital-to-analog converter circuits is to switch P-type transistor switch and N-type transistor Substrate is respectively coupled to operating voltage AVDD and ground voltage AGND, as shown in figure 3, correspond to large code (such as FEH, FFH the voltage level (such as VGM2, VGM1, VGM17, VGM18) that transistor) is transmitted can be closer to operating voltage AVDD or Ground voltage AGND corresponds to the voltage level (example transmitted compared with the transistor of lower Item (such as 00H, 01H) in comparison Such as VGM9, VGM8, VGM10, VGM11) if can be closer to half voltage level AHVDD, lead to the cross-pressure between its source electrode and substrate Larger, the substrate effect for causing it to generate is also more obvious.

Summary of the invention

In consideration of it, the present invention proposes a kind of digital-to-analog converter circuits and its operation method, effectively to solve existing skill The above problem that art is suffered from.

A specific embodiment according to the present invention is a kind of digital-to-analog converter circuits.In this embodiment, digital mould Quasi- converter circuit is applied to source electrode driving device.Digital-to-analog converter circuits include multiple P-type transistors switch, multiple N Transistor npn npn switch and substrate voltage control unit.Multiple P-type transistor switch is concatenated with one another.Multiple N-type transistor is opened It closes concatenated with one another.Substrate voltage control unit is respectively coupled to the substrate and multiple N-type transistor that multiple P-type transistor switchs The substrate of switch, the substrate to control multiple P-type transistor switch have first substrate voltage and multiple N-type transistor The substrate of switch has the second substrate voltage.First substrate voltage is that operating voltage subtracts particular voltage difference and the second substrate voltage Particular voltage difference is added for ground voltage.Operating voltage is higher than ground voltage.

In an embodiment, substrate voltage control unit is according to multiple P-type transistor switch and multiple N-type transistor The element characteristic of switch determines the size of particular voltage difference, and the start-up resistor to reduce those transistor switches and critical voltage are simultaneously It avoids generating situation about leading to along local derviation.

In an embodiment, if the source electrode of multiple P-type transistor switch receives the first input data signal and has the Source voltage, then the voltage difference between the first source voltage and first substrate voltage of multiple P-type transistor switch is less than Voltage difference between first source voltage and operating voltage.

In an embodiment, the first input data signal has the voltage of the half of approach operating voltage, causes the first source The half of pole tension approach operating voltage.

In an embodiment, the first input data signal has the voltage of approach operating voltage, causes the first source voltage Approach operating voltage and particular voltage difference levels off to zero.

In an embodiment, if the source electrode of multiple N-type transistor switch receives one second input data signal and has One second source voltage, the then voltage difference between the second source voltage and the second substrate voltage that multiple N-type transistor switchs Less than the voltage difference between the second source voltage and ground voltage.

In an embodiment, the second input data signal has the voltage of the half of approach operating voltage, causes the second source The half of pole tension approach operating voltage.

In an embodiment, the second input data signal has the voltage of approach ground voltage, causes the second source voltage Approach ground voltage and particular voltage difference levels off to zero.

In an embodiment, source electrode driving device also include operational amplifier and operational amplifier have first input end, Second input terminal and output end.The first input end of operational amplifier is coupled to each other with output end.

In an embodiment, one end of multiple P-type transistor switch concatenated with one another is coupled to the of operational amplifier Two input terminals.

In an embodiment, source electrode driving device also includes divider resistance string, and divider resistance string includes concatenated with one another Multiple divider resistances, the other end of multiple P-type transistor switch concatenated with one another are coupled to one end of divider resistance string or appoint Between two adjacent divider resistances, to receive the first input data signal.

In an embodiment, one end of multiple N-type transistor switch concatenated with one another is coupled to the of operational amplifier Two input terminals.

In an embodiment, source electrode driving device also includes divider resistance string, and divider resistance string includes concatenated with one another Multiple divider resistances, the other end of multiple N-type transistor switch concatenated with one another are coupled to one end of divider resistance string or appoint Between two adjacent divider resistances, to receive the second input data signal.

It is according to another embodiment of the present invention a kind of digital-to-analog converter circuits operation method.In this embodiment In, digital-to-analog converter circuits operation method is to operate the digital-to-analog converter circuits in source electrode driving device.Number Analog converter circuit includes multiple P-type transistors switch, multiple N-type transistors switch and a substrate voltage control unit.It should It is concatenated with one another that multiple P-type transistors switch concatenated with one another and multiple N-type transistor switch.Substrate voltage control unit distinguishes coupling Connect the substrate of multiple P-type transistor switch and the substrate of multiple N-type transistor switch.

Digital-to-analog converter circuits operation method comprises the steps of (a) and determines a particular voltage difference；(b) by work Voltage subtracts particular voltage difference and obtains first substrate voltage and control the substrate of multiple P-type transistor switch with first substrate Voltage；And ground voltage (c) is obtained into the second substrate voltage plus particular voltage difference and controls multiple N-type transistor switch Substrate have the second substrate voltage, wherein operating voltage be higher than ground voltage.

In an embodiment, step (a) switchs the member switched with multiple N-type transistor according to multiple P-type transistor Part characteristic determines the size of the particular voltage difference, to reduce the start-up resistors of those transistor switches and critical voltage and avoid producing Raw situation about leading to along local derviation.

In an embodiment, if the source electrode of multiple P-type transistor switch receives one first input data signal and has One first source voltage, the then electricity between first source voltage and the first substrate voltage that multiple P-type transistor switchs Pressure difference is less than the voltage difference between first source voltage and the operating voltage.

In an embodiment, which has the voltage for the half for approaching the operating voltage, causes this First source voltage approaches the half of the operating voltage.

In an embodiment, which has the voltage for approaching the operating voltage, causes first source Pole tension approaches the operating voltage and the particular voltage difference levels off to zero.

In an embodiment, if the source electrode of multiple N-type transistor switch receives one second input data signal and has One second source voltage, the then electricity between second source voltage and the second substrate voltage that multiple N-type transistor switchs Pressure difference is less than the voltage difference between second source voltage and the ground voltage.

In an embodiment, which has the voltage for the half for approaching the operating voltage, causes this Second source voltage approaches the half of the operating voltage.

In an embodiment, which has the voltage for approaching the ground voltage, causes second source Pole tension approaches the ground voltage and the particular voltage difference levels off to zero.

Compared to the prior art, digital-to-analog converter circuits of the invention and its operation method pass through according to its transistor The element characteristic of switch changes the mode of substrate voltage level to reduce the substrate effect of existing transistor switch, so that crystal The start-up resistor and critical voltage of pipe switch can reduce and can avoid generating situation about leading to along local derviation, by accelerate digital simulation The reaction speed of converter circuit will not influence channel operation amplifier offer output signal and fill to liquid crystal display panel charging The electric time is conducive to the design of rear end channel operation amplifier circuit.

It can be obtained further by detailed description of the invention below and appended attached drawing about the advantages and spirit of the present invention Solution.

Detailed description of the invention

Figure 1A shows the substrate of the P-type transistor switch concatenated with one another in the digital-to-analog converter circuits of the prior art It is coupled to the schematic diagram of operating voltage.

Figure 1B shows the substrate of the N-type transistor switch concatenated with one another in the digital-to-analog converter circuits of the prior art It is coupled to the schematic diagram of ground voltage.

Fig. 2 shows when divider resistance string provides different voltage levels and transmits via digital-to-analog converter circuits, The source electrode and substrate of transistor switch in digital-to-analog converter circuits are generated against partially, and critical voltage is caused to increase and generate base The schematic diagram of plate effect.

Fig. 3 shows the voltage level for corresponding to and being transmitted compared with the transistor of lower Item and is closer to half voltage level, leads to it Cross-pressure between source electrode and substrate is larger and generates the schematic diagram of obvious substrate effect.

Fig. 4 A shows the digital-to-analogue conversion of the digital-to-analog converter circuits in a specific embodiment according to the present invention Device includes the schematic diagram of multiple P-type transistors switch.

Fig. 4 B shows the digital-to-analogue conversion of the digital-to-analog converter circuits in a specific embodiment according to the present invention Device includes the schematic diagram of multiple N-type transistors switch.

Conducting resistance and critical voltage pair of the present invention with the transistor switch of the prior art is shown respectively in Fig. 5 A and Fig. 5 B The comparison figure of dram-source voltage.

Fig. 6 shows the flow chart of driving circuit operation method according to another embodiment of the present invention.

Main element symbol description:

PM0~PM7:P transistor npn npn switch

NM0~NM7:N transistor npn npn switch

AVDD: operating voltage

AGND: ground voltage

AHVDD: half voltage level

00H, 01H, 1FH, 3FH, 7FH, BFH, DFH, FEH, FFH: coding

SA0~SA7, SB0~SB7: control signal

INH: the first input data signal

INL: the second input data signal

OP: operational amplifier

: first input end

+: the second input terminal

DAC0~DAC255: digital analog converter

SIN: input signal

SOUT: output signal

RS: divider resistance string

R: divider resistance

WL: line load

INL0~INL255: input data signal

VGM1~VGM18: voltage level

AVDD- Δ V: first substrate voltage

AGND+ Δ V: the second substrate voltage

S10~S14: step

Specific embodiment

A specific embodiment according to the present invention is a kind of digital-to-analog converter circuits.In this embodiment, digital mould Quasi- source electrode driving device of the converter application in display, and digital-to-analog converter circuits can include multiple as Fig. 3 Digital analog converter.Those digital analog converters can be switched or by the multiple P-type transistors being one another in series by going here and there each other Multiple N-type transistors switch of connection is constituted.The substrate of those P-type transistors switch and the substrate of those N-type transistors switch It can be respectively coupled to first substrate voltage and the second substrate voltage, wherein first substrate voltage is higher than the second substrate voltage.

As shown in Figure 4 A, the digital analog converter in digital-to-analog converter circuits may include that multiple P-type transistors are opened Close PM0~PM7.Those P-type transistor switches PM0~PM7 is sequentially concatenated with one another and those P-type transistor switches PM0~PM7 Grid receives control signal SA0~SA7 respectively.The substrate of those P-type transistor switches PM0~PM7 can couple first substrate electricity Press (AVDD- Δ V) and first substrate voltage (AVDD- Δ V) that can be provided by substrate voltage control unit (not shown go out), but not with This is limited.First substrate voltage (AVDD- Δ V) can be operating voltage AVDD and subtract particular voltage difference Δ V.For example, special Constant voltage difference Δ V can be 2 volts, and but not limited to this.

In practical application, the size of first substrate voltage (AVDD- Δ V) can according to those P-type transistor switches PM0~ The element characteristic of PM7 and determine, as long as start-up resistor and the critical voltage for reducing transistor switch can be reached and avoid generating Along local derviation lead to situation, visual actual demand and adjust.

If the source electrode of those P-type transistor switches PM0~PM7 receives the first input data signal INH and has the first source Pole tension, then between the first source voltage of those P-type transistor switches PM0~PM7 and first substrate voltage (AVDD- Δ V) Voltage difference can be less than the voltage difference between the first source voltage and operating voltage (AVDD).That is, due to those p-types crystalline substance The substrate voltage of body pipe switch PM0~PM7 is reduced to first substrate voltage (AVDD- Δ V) by traditional operating voltage AVDD, so that Cross-pressure between the source electrode and substrate of those P-type transistor switches PM0~PM7 becomes smaller, therefore can effectively reduce its substrate effect.

When the first input data signal INH has the half (that is, half voltage level AHVDD) of approach operating voltage AVDD Voltage when, can make the first source voltage approach operating voltage AVDD half (that is, half voltage level AHVDD).When first defeated Enter data-signal INH have approach operating voltage AVDD voltage when, can make the first source voltage approach operating voltage AVDD and Particular voltage difference Δ V levels off to zero.

As shown in Figure 4 B, the digital analog converter in digital-to-analog converter circuits may include that multiple N-type transistors are opened Close NM0~NM7.Those N-type transistor switches NM0~NM7 is sequentially concatenated with one another and those N-type transistor switches NM0~NM7 Grid receives control signal SB0~SB7 respectively.The substrate of those N-type transistor switches NM0~NM7 can couple the second substrate electricity It presses (AGND+ Δ V), and the second substrate voltage (AGND+ Δ V) can be provided by substrate voltage control unit (not shown go out), but not As limit.The second substrate voltage (AGND+ Δ V) can be ground voltage AGND plus particular voltage difference Δ V.For example, Particular voltage difference Δ V can be 2 volts, and but not limited to this.

In practical application, the size of the second substrate voltage (AGND+ Δ V) can according to those N-type transistor switches NM0~ The element characteristic of NM7 and determine, as long as start-up resistor and the critical voltage for reducing transistor switch can be reached and avoid generating Along local derviation lead to situation, visual actual demand and adjust.

If the source electrode of those N-type transistor switches NM0~NM7 receives the second input data signal INL and has the second source Pole tension, then between the second source voltage of those N-type transistor switches NM0~NM7 and the second substrate voltage (AGND+ Δ V) Voltage difference can be less than the voltage difference between the second source voltage and ground voltage AGND.That is, due to those N-type crystal The substrate voltage of pipe switch NM0~NM7 rises to the second substrate voltage (AGND+ Δ V) by traditional ground voltage AGND, so that Cross-pressure between the source electrode and substrate of those N-type transistor switches NM0~NM7 becomes smaller, therefore can effectively reduce its substrate effect.

When the second input data signal INL has the half (that is, half voltage level AHVDD) of approach operating voltage AVDD Voltage when, can make the second source voltage approach operating voltage AVDD half (that is, half voltage level AHVDD).When second defeated Enter data-signal INL have approach ground voltage AGND voltage when, can make the second source voltage approach ground voltage AGND and Particular voltage difference Δ V levels off to zero.

In practical application, one end of those P-type transistor switches PM0~PM7 concatenated with one another in Fig. 4 A can be as Fig. 2 be equally coupled to the second input terminal+of operational amplifier OP and operational amplifier OP first input end-and output end that This coupling, and the other end of those P-type transistor switches PM0~PM7 can then be coupled to divider resistance string RS's as Fig. 2 Between one end or any two adjacent divider resistance R, to receive the first input data signal INH.

Similarly, one end of those N-type transistor switches NM0~NM7 concatenated with one another in Fig. 4 B can as Fig. 2 coupling The first input end-of the second input terminal+and operational amplifier OP that are connected to operational amplifier OP is coupled to each other with output end, and The other end of those N-type transistor switches NM0~NM7 can then be coupled to one end of divider resistance string RS or be appointed as Fig. 2 Between two adjacent divider resistance R, to receive the second input data signal INL.

Then, the transistor switch of the present invention with the prior art is shown respectively in A and Fig. 5 B, Fig. 5 A and Fig. 5 B referring to figure 5. Conducting resistance RON compared with critical voltage VTH is to dram-source voltage VDS figure.

As shown in Figure 5A, the conducting resistance curve of the transistor switch of the present invention and the prior art be respectively RON1 with RON0, if can obviously be found: the electric conduction of transistor switch of the invention so that dram-source voltage VDS is equal to 4 volts as an example Hinder conducting resistance curve RON0 of the curve RON1 lower than the transistor switch of the prior art.

As shown in Figure 5 B, the critical voltage curve of the transistor switch of the present invention and the prior art be respectively VTH1 with VTH0, if can obviously be found: the critical electricity of transistor switch of the invention so that dram-source voltage VDS is equal to 4 volts as an example Critical voltage curve VTH0 of the line VTH1 that buckles lower than the transistor switch of the prior art.

According to Fig. 5 A and Fig. 5 B: since the present invention opens those P-type transistors in digital-to-analog converter circuits The substrate voltage of pass is reduced to first substrate voltage (AVDD- Δ V) by traditional operating voltage AVDD and is opened those N-type transistors The substrate voltage of pass rises to the second substrate voltage (AGND+ Δ V) by traditional ground voltage AGND, so that those P-type crystals Cross-pressure between pipe switch and the source electrode and substrate of those N-type transistors switch can become smaller, therefore can effectively reduce its substrate effect It answers, reach the start-up resistor for reducing transistor switch and critical voltage and avoids generating the specific effect led to along local derviation.

It is according to another embodiment of the present invention a kind of digital-to-analog converter circuits operation method.In this embodiment In, digital-to-analog converter circuits operation method is to operate the digital-to-analog converter circuits in source electrode driving device.Number Analog converter circuit includes multiple P-type transistors switch, multiple N-type transistors switch and substrate voltage control unit.This is more It is concatenated with one another that a P-type transistor switchs concatenated with one another and multiple N-type transistor switch.Substrate voltage control unit is respectively coupled to The substrate of multiple P-type transistor switch and the substrate of multiple N-type transistor switch.

Fig. 6 is please referred to, Fig. 6 shows the flow chart of the driving circuit operation method in this embodiment.As shown in fig. 6, digital Analog converter circuit operation method may include the following steps:

Step S10: particular voltage difference is determined；

Step S12: operating voltage is subtracted into particular voltage difference and obtains first substrate voltage and controls multiple P-type transistor The substrate of switch has first substrate voltage；And

Step S14: ground voltage is obtained into the second substrate voltage plus particular voltage difference and controls multiple N-type transistor The substrate of switch has the second substrate voltage.Wherein, operating voltage can be higher than ground voltage.

In practical application, step S10 switchs the member switched with multiple N-type transistor according to multiple P-type transistor Part characteristic determines the size of particular voltage difference, to reduce the start-up resistors of those transistor switches and critical voltage and avoid generating Situation about leading to along local derviation.

If the source electrode of multiple P-type transistor switch receives the first input data signal and has the first source voltage, Voltage difference between the first source voltage and first substrate voltage of multiple P-type transistor switch can be less than the first source voltage Voltage difference between operating voltage.When the first input data signal has the voltage of the half of approach operating voltage, can make The half of first source voltage approach operating voltage；When the first input data signal has the voltage of approach operating voltage, meeting Make the first source voltage approach operating voltage and particular voltage difference levels off to zero.

If the source electrode of multiple N-type transistor switch receives the second input data signal and has the second source voltage, Voltage difference between the second source voltage and the second substrate voltage of multiple N-type transistor switch can be less than the second source voltage Voltage difference between ground voltage.When the second input data signal has the voltage of the half of approach operating voltage, can make The half of second source voltage approach operating voltage；When the second input data signal has the voltage of approach ground voltage, meeting Make the second source voltage approach ground voltage and particular voltage difference levels off to zero.

Compared to the prior art, digital-to-analog converter circuits of the invention and its operation method pass through according to its transistor The element characteristic of switch changes the mode of substrate voltage level to reduce the substrate effect of existing transistor switch, so that crystal The start-up resistor and critical voltage of pipe switch can reduce and can avoid generating situation about leading to along local derviation, by accelerate digital simulation The reaction speed of converter circuit will not influence channel operation amplifier offer output signal and fill to liquid crystal display panel charging The electric time is conducive to the design of rear end channel operation amplifier circuit.

By the above detailed description of preferred embodiments, it would be desirable to feature and spirit of the invention are more clearly described, and simultaneously It is non-that scope of the invention is limited with above-mentioned disclosed preferred embodiment.On the contrary, the purpose is to wish Various changes can be covered and have being arranged in the scope of the scope of the patents to be applied of the invention of equality.By above preferable The detailed description of specific embodiment, it would be desirable to feature of the invention and spirit are more clearly described, and not with above-mentioned disclosed Preferred embodiment limits scope of the invention.On the contrary, the purpose is to wish to cover various changes and tool Equality is arranged in the scope of the scope of the patents of the invention to be applied.