JP2006191568A - Integrated circuit device provided with control circuit to control amplifier output stage and its driving method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an integrated circuit device provided with an amplification circuit to generate an output voltage. <P>SOLUTION: Bias controlling circuits (215 and 216) generate bias controlling voltages (VB1 and VB2) or output voltages (VOUT+ and VOUT-) selectively from their outputs based on a state of a control signal (SW). An output stage driver circuit (213) operates responding to the voltages generated from the outputs of the bias controlling circuits. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an integrated circuit device and a driving method thereof, and more particularly to an integrated circuit device including a bias control circuit and a driving method thereof.

  In general, an operational amplifier OP-AMP having two or more stages uses a compensation capacitor to ensure stability. For example, as shown in FIG. 1, the conventional source driver circuit 100 includes an amplifier 110, a switch 120, and a load 130. Amplifier 110 amplifies the input and generates an output for load 130 through switch 120. The amplifier 110 may be designed to have a constant slew rate and stability within specific frequency and phase characteristics. Thus, the amplifier 110 may be designed to drive the load 130. As the load 130 increases, the frequency and phase characteristics deteriorate. This also increases the DC current consumption.

  Therefore, an object of the present invention is to provide an integrated circuit device including an amplifier circuit that generates an output voltage.

  An integrated circuit device according to an embodiment of the present invention includes an amplifier circuit that generates an output voltage, a bias control circuit that generates a bias control voltage or an output voltage from the output based on a state of a control signal, and an output of the bias control circuit. An output stage driver circuit that operates in response to the generated voltage is provided.

  The output stage driver circuit includes a totem-pole output stage driver.

  The output current generated through the output stage driver circuit in response to the bias control voltage is smaller than the output current generated through the output stage driver circuit in response to the output voltage.

  The integrated circuit device according to an embodiment of the present invention further includes a switch that operates in response to the control signal, and a load that is connected to the output stage driver circuit through the switch, and the bias control circuit receives the control signal. In response, a bias control voltage is generated from the output when the switch is open, and an output voltage is generated from the output when the switch is closed in response to the control signal.

  An integrated circuit device according to another embodiment of the present invention includes an amplifier circuit that generates first and second output voltages, a first bias control voltage or a first output voltage that is generated from the output based on the state of a control signal. 1 bias control circuit, a first bias control circuit for generating a second bias control voltage or a second output voltage from its output based on the state of the control signal, and an output of the first and second bias control circuits An output stage driver circuit that operates in response to a voltage is provided.

  The output current generated through the output stage driver circuit in response to the first and second bias control voltages is smaller than the output current generated through the output stage driver circuit in response to the first and second output voltages.

  The output stage driver circuit includes a totem pole output stage driver.

  The totem pole output stage driver includes a PMOS transistor that operates in response to a voltage at the output of the first bias control circuit, and an NMOS transistor that operates in response to a voltage at the output of the second bias control signal. .

  The first bias control voltage is higher than the first output voltage, and the second bias control voltage is lower than the second output voltage.

  The integrated circuit device according to another embodiment of the present invention may further include a switch that operates in response to the control signal, and a load connected to the output stage driver circuit through the switch, the first and second bias controls. Each circuit generates the first and second bias control voltages from these outputs when the switch is open in response to the control signal, and the switch is closed in response to the control signal. At some point, the first and second output voltages are generated from their outputs.

  A method of operating an integrated circuit device according to an embodiment of the present invention includes generating an output voltage, generating a bias control voltage or an output voltage from an output of a bias control circuit based on a state of a control signal, and the bias control. Driving the output stage driver circuit using a voltage generated from the output of the circuit.

  The output current generated through the output stage driver circuit in response to the bias control voltage is smaller than the output current generated through the output stage driver circuit in response to the output voltage.

  A method of operating an integrated circuit according to an embodiment of the present invention includes: generating a bias control voltage from an output of the bias control circuit when a switch is open in response to the control signal; and The method may further include generating the output signal from the output of the bias control circuit when the switch is closed in response.

  A method of operating an integrated circuit device according to another embodiment of the present invention includes generating a first and second output voltage, a first bias control voltage from an output of a first bias control circuit based on a state of a control signal, or Generating a first output voltage; generating a second bias control voltage or a second output voltage from an output of a second bias control circuit based on a state of the control signal; and the first and second bias control circuits. Driving the output stage driver circuit using the voltage generated from the output of the output stage.

  The output current generated through the output stage driver circuit in response to the first and second bias voltages is smaller than the output current generated through the output stage driver circuit in response to the first and second output voltages.

  The first bias control voltage is higher than the first output voltage, and the second bias voltage is lower than the second output voltage.

  According to another embodiment of the present invention, a method of operating an integrated circuit device includes first and second biases from outputs of the first and second bias control circuits when a switch is open in response to the control signal. Generating each of the control voltages, and generating each of the first and second output voltages from the outputs of the first and second bias control circuits when the switch is closed in response to the control signal. Further included.

  The integrated circuit device according to the present invention can prevent a decrease in frequency and phase characteristics and reduce DC current consumption.

  Hereinafter, in order to facilitate understanding of the drawings cited in the detailed description of the present invention, a brief description of each drawing is provided.

  For a full understanding of the invention and the operational advantages thereof and the objects achieved by the practice of the invention, reference should be made to the accompanying drawings that illustrate preferred embodiments of the invention and the contents described in the drawings. I have to.

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. The same reference numerals provided in each drawing denote the same members.

  FIG. 2 is a block diagram of a load driving system 200 according to an embodiment of the present invention. The load driving system includes an amplifier 210, a switch 220, and a load 230. The switch 220 is opened and closed based on the logic state of the control signal SW. When switch 220 is closed, the output of amplifier 210 is applied to load 230. If the switch is open, the output of the amplifier 210 is not applied to the load 230.

  According to the embodiment of the present invention, the amplifier 210 includes an operational transconductance amplifier (OTA) 211, a bias controller 212, and an output unit 213. The OTA 211 generates at least one amplified signal / voltage from one or more of its outputs. The bias controller 212 is responsive to the switch control signal SW and generates a bias control voltage or at least one amplified signal from its output. The output unit 213 generates an output signal OUTPUT in response to the signal / voltage output from the bias control unit 212. According to the embodiment of the present invention, the output unit 213 may also include a totem pole output stage driver circuit.

  Desirably, the output 213 may be biased differently depending on whether the load 230 is coupled to the output of the amplifier 210. By appropriately biasing the output 213 when the load 230 is not coupled to the amplifier 210, current usage by the amplifier can be reduced.

  FIG. 3 is a circuit diagram of a load driving system according to another embodiment of the present invention. As shown in FIG. 3, the bias controller 212 includes a first bias controller 215 and a second bias controller 216. The output unit 213 includes transistors P1 and N1 arranged in a totem pole structure.

  The OTA 211 receives the input signal INPUT through the VIN + node, and receives the output signal OUTPUT as a feedback signal from the output unit 213 through the VIN− node. The OTA 211 can output the first differential signal / voltage VOUT− and the second differential signal / voltage VOUT +. The first bias controller 215 generates a first bias signal / voltage VB1 and selectively outputs the first differential signal VOUT− or the first bias signal / voltage VB1 based on the logic state of the switch control signal SW. . The second bias controller 216 generates a second bias signal / voltage VB2, and selectively outputs the second differential signal VOUT + or the first bias signal / voltage VB2 based on the logic state of the switch control signal SW. In the embodiment of the present invention, if the switch control signal SW indicates that the load 230 is connected to the amplifier 210, VOUT− and VOUT + are output to the output unit 213. On the other hand, if the switch control signal SW indicates that the load 230 is not connected to the amplifier 210, VB1 and VB2 are output to the output unit 213. In the embodiment of the present invention, VB1> VOUT− and VB2 <VOUT +.

  As shown in FIG. 3, the output unit 213 includes transistors P1 and N1. The gate of P1 receives the output signal / voltage from the first bias controller 215, and the gate of N1 receives the output signal / voltage from the second bias controller 216.

  FIG. 4 is a waveform diagram for explaining the operation of the load driving system according to the embodiment of the present invention shown in FIGS. 2 and 3. The input signal INPUT is amplified by the OTA 211 before the SW signal is driven to connect the load 230 to the amplifier 210 through the switch 220. In this case, however, bias signals / voltages VB 1 and VB 2 are applied to the output unit 213. As a result, the output current Iout at the output unit 213 is relatively small. At this time, the output signal / voltage OUTPUT is not transmitted to the load 230. When the switch control signal SW is driven “high” and the load 230 is connected to the amplifier 210 through the switch 220, the differential signals VOUT + and VOUT− are applied to the output unit 213. At this time, the output signal / voltage OUTPUT is transmitted to the load 230. As a result, the output current Iout at the output unit 213 is relatively large. In the embodiment of the present invention, the output current Iout through the output unit 213 varies depending on the logic state of the switch control signal SW.

  In an embodiment of the present invention, the OTA 211 may not generate VOUT +. In this case, the second bias controller 216 may apply a constant bias to the output unit 213 transistor N1. Except that a constant signal / voltage VB3 is generated by the second bias control unit 216 and applied to the output unit 213 transistor N1, the operation of the load driving system is the same as the description of FIG. The signal / voltage has the following relationship: VB1> VOUT− and VB2 <VB3.

  As described above, the optimal embodiment has been disclosed in the drawings and specification. Although specific terms are used herein, they are merely used to describe the present invention and are intended to limit the scope of the invention as defined in the meaning and claims. It was not used for Accordingly, those skilled in the art will appreciate that various modifications and equivalent other embodiments are possible. Therefore, the true technical protection scope of the present invention should be determined by the technical idea of the claims.

  The present invention can be suitably applied to technical fields related to an integrated circuit device and a driving method thereof.

It is a block diagram of the conventional source driver circuit. 1 is a block diagram of a load driving system according to an embodiment of the present invention. FIG. 3 is a circuit diagram of a load driving system according to another embodiment of the present invention. FIG. 4 is a waveform diagram for explaining the operation of the load driving system according to the embodiment of the present invention shown in FIGS. 2 and 3.

Explanation of symbols

210 Amplifier 211 Operational transconductance amplifier (OTA)
212 bias controller 213 output unit 215 first bias control unit 216 second bias control unit 230 load P1, N1 transistor INPUT input signal OUTPUT output signal VB1 first bias signal / voltage VB2 second bias signal / voltage SW switch control signal VOUT − First differential signal VOUT + second differential signal

Claims (17)

An amplifier circuit for generating an output voltage;
A bias control circuit that generates a bias control voltage or output voltage from its output based on the state of the control signal; and
An integrated circuit device comprising: an output stage driver circuit that operates in response to a voltage generated from an output of the bias control circuit.   The integrated circuit device according to claim 1, wherein the output stage driver circuit includes a totem pole output stage driver.   The output current generated through the output stage driver circuit in response to the bias control voltage is smaller than the output current generated through the output stage driver circuit in response to the output voltage. Integrated circuit device. A switch that operates in response to the control signal;
A load coupled to the output stage driver circuit through the switch;
The bias control circuit generates a bias control voltage from the output when the switch is open in response to the control signal, and outputs the output voltage from the output when the switch is closed in response to the control signal. The integrated circuit device according to claim 1, wherein: An amplifier circuit for generating first and second output voltages;
A first bias control circuit for generating a first bias control voltage or a first output voltage from its output based on the state of the control signal;
A second bias control circuit for generating a second bias control voltage or a second output voltage from its output based on the state of the control signal;
An integrated circuit device comprising: an output stage driver circuit that operates in response to a voltage generated from outputs of the first and second bias control circuits.   The output current generated through the output stage driver circuit in response to the first and second bias control voltages is smaller than the output current generated through the output stage driver circuit in response to the first and second output voltages. The integrated circuit device according to claim 5.   The integrated circuit device according to claim 6, wherein the output stage driver circuit includes a totem pole output stage driver.   The totem pole output stage driver includes a PMOS transistor that operates in response to a voltage at the output of the first bias control circuit, an NMOS transistor that operates in response to a voltage at the output of the second bias control circuit, The integrated circuit device according to claim 7, further comprising:   9. The integrated circuit device according to claim 8, wherein the first bias control voltage is higher than the first output voltage, and the second bias control voltage is lower than the second output voltage. A switch that operates in response to the control signal;
A load coupled to the output stage driver circuit through the switch;
Each of the first and second bias control circuits generates the first and second bias control voltages from their outputs and responds to the control signal when the switch is open in response to the control signal. 6. The integrated circuit device according to claim 5, wherein when the switch is in a closed state, the first and second output voltages are generated from their outputs. In a method of operating an integrated circuit device,
Generating an output voltage;
Generating a bias control voltage or output voltage from the output of the bias control circuit based on the state of the control signal;
Driving the output stage driver circuit using a voltage generated from the output of the bias control circuit.   The output current generated through the output stage driver circuit in response to the bias control voltage is smaller than the output current generated through the output stage driver circuit in response to the output voltage. Method. Generating the bias control voltage from the output of the bias control circuit when a switch is open in response to the control signal;
12. The method of claim 11, further comprising generating the output signal from the output of the bias control circuit when the switch is closed in response to the control signal. In a method of operating an integrated circuit device,
Generating first and second output voltages;
Generating a first bias control voltage or a first output voltage from the output of the first bias control circuit based on the state of the control signal;
Generating a second bias control voltage or a second output voltage from the output of the second bias control circuit based on the state of the control signal;
Driving the output stage driver circuit using a voltage generated from the outputs of the first and second bias control circuits.   The output current generated through the output stage driver circuit in response to the first and second bias voltages is smaller than the output current generated through the output stage driver circuit in response to the first and second output voltages. 15. A method according to claim 14, characterized in that   The method of claim 15, wherein the first bias control voltage is higher than the first output voltage and the second bias voltage is lower than the second output voltage. Generating first and second bias control voltages from the outputs of the first and second bias control circuits, respectively, when a switch is open in response to the control signal;
The method further comprises generating the first and second output voltages from outputs of the first and second bias control circuits, respectively, when the switch is closed in response to the control signal. Item 15. The method according to Item 14.

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