JP2016152670A - Circuit device, electro-optic device and electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a circuit device capable of self-detecting the abnormality of a step-up voltage generated by a step-up circuit, and resetting the step-up operation of the step-up circuit to a normal state, and to provide an electro-optic device, an electronic apparatus, and the like.SOLUTION: A circuit device includes a power supply circuit having a step-up circuit 160, and an abnormality detection circuit 130 for detecting the abnormality of a step-up voltage VB generated based on the step-up operation of the step-up circuit 160. The abnormality detection circuit 130 has a detection transistor TDET. The detection transistor TDET is provided between the node of a first power supply voltage and the node of the step-up voltage VB, and an input voltage VNB1 based on a second power supply voltage is inputted to the gate thereof. The abnormality detection circuit 130 detects the abnormality of the step-up voltage VB, based on the voltage change on one of the source or drain of the detection transistor TDET.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a circuit device, an electro-optical device, an electronic apparatus, and the like.

  A display driver that drives a display panel requires various voltages such as a source drive amplifier power supply, a gate drive amplifier power supply, a gradation voltage generation circuit power supply, and a display panel common voltage. It has a built-in power supply circuit. For example, in Patent Documents 1 and 2, a power supply circuit having a plurality of booster circuits (primary booster circuit to quaternary booster circuit) and a source that operates by being supplied with power generated by the boosting operation of the booster circuit of the power supply circuit. A display driver including a driver and a gate driver is disclosed.

JP 2007-212897 A JP 2010-145738

  In such a display driver that generates a driving power supply by boosting operation, a large current flows through the parasitic bipolar of the boosting circuit due to noise or garbled register value data, and so-called power supply jamming occurs. As a result, the boosting operation of the booster circuit cannot be restored to the normal state.

  In the case of display drivers for mobile devices, even when such power supply jamming occurs, the power supply jamming is resolved by the user turning off the power switch of the mobile device, and the normal state is restored. it can. However, in a display driver for in-vehicle use, for example, the power supplied to the display driver cannot be turned off unless the engine is turned off.

  According to some aspects of the present invention, a circuit device, an electro-optical device, an electronic device, and the like that can detect an abnormality in a boosted voltage generated by a booster circuit and return the boosting operation of the booster circuit to a normal state. Can be provided.

  One embodiment of the present invention includes a power supply circuit having a booster circuit, and an abnormality detection circuit that detects an abnormality of a boosted voltage generated based on the boosting operation of the booster circuit, and the abnormality detection circuit includes a high potential side Provided between the node of the first power supply voltage, which is one of the power supply voltage and the low potential power supply voltage, and the node of the boosted voltage, and is the other of the high potential power supply voltage and the low potential power supply voltage The present invention relates to a circuit device having a detection transistor to which an input voltage based on a second power supply voltage is input to a gate, and detecting an abnormality of the boosted voltage based on a voltage change of one of a source and a drain of the detection transistor. .

  According to one embodiment of the present invention, the abnormality detection circuit detects an abnormality of the boost voltage based on a voltage change of one of the source and the drain of the detection transistor, so that the abnormality of the boost voltage generated by the boost circuit can be self-detected. . Since the abnormality detection circuit can detect the abnormality of the boosted voltage, the return operation can be performed based on the detection result, and the boost operation of the booster circuit can be returned to the normal state.

  In the aspect of the invention, the abnormality detection circuit may include a resistance element provided between the one of the source and the drain of the detection transistor and the node of the first power supply voltage.

  One voltage of the source and drain of the detection transistor is a voltage obtained by resistance division between the first power supply voltage and the boosted voltage by the resistance element and the on-resistance of the detection transistor. When the boosted voltage changes, the other voltage of the source and drain of the detection transistor changes, so that the on-resistance of the detection transistor changes. As a result, the resistance division ratio changes, so that the voltage of one of the source and drain of the detection transistor changes, and it is possible to detect an abnormality in the boosted voltage.

  In the aspect of the invention, the abnormality detection circuit is provided between the one of the source and the drain of the detection transistor and the node of the first power supply voltage, and the input voltage is input to a gate. A first transistor may be included.

  One voltage of the source and drain of the detection transistor is a voltage obtained by resistance-dividing between the first power supply voltage and the boosted voltage by the on-resistance of the first transistor and the on-resistance of the detection transistor. When the boosted voltage changes, the other voltage of the source and drain of the detection transistor changes, so that the on-resistance of the detection transistor changes. As a result, the resistance division ratio changes, so that the voltage of one of the source and drain of the detection transistor changes, and it is possible to detect an abnormality in the boosted voltage.

  In one embodiment of the present invention, a second transistor may be provided between the other of the source and the drain of the detection transistor and the node of the boosted voltage, and the drain and the gate are connected.

  In this way, the detection voltage for detecting an abnormality can be adjusted by providing the second transistor connected to the drain and the gate on the other side of the source and the drain of the detection transistor. That is, the second transistor has a so-called diode connection, and the other voltage of the source and drain of the detection transistor increases by the forward voltage. As a result, the gate-source voltage of the detection transistor is reduced by the forward voltage of the diode connection, and the detection voltage is adjusted.

  In the aspect of the invention, the abnormality detection circuit may detect that the boost voltage is abnormal when the boost voltage exceeds the detection voltage, and the detection voltage may have a hysteresis characteristic.

  Since the detection voltage has a hysteresis characteristic, when the boosted voltage is in the vicinity of the detection voltage, it is possible to suppress the result of abnormality detection from repeating normal / abnormal inversion.

  In the aspect of the invention, the abnormality detection circuit may include a buffer circuit that buffers the one of the source and drain voltages of the detection transistor, the gate of the detection transistor, and a node of the second power supply voltage. And a first transistor provided between the node of the first power supply voltage and the gate of the detection transistor. A resistor element; and a second resistor element provided between the gate of the detection transistor and the node of the second power supply voltage and connected in parallel to the third transistor.

  The output of the buffer circuit that buffers one of the source and drain voltages of the detection transistor is logically inverted when an abnormality in the boosted voltage is detected, thereby controlling on / off of the third transistor. Since the third transistor is connected in parallel to the second resistance element provided between the gate of the detection transistor and the node of the second power supply voltage, the detection transistor is turned on and off by the third transistor. The gate voltage changes. Thereby, a detection voltage comes to have a hysteresis characteristic.

  In the aspect of the invention, the boosted voltage is a negative voltage, the first power supply voltage is the high-potential-side power supply voltage, and the second power supply voltage is the low-potential-side power supply voltage. There may be.

  In this way, the detection transistor is provided between the node of the high potential side power supply voltage and the node of the negative boost voltage, and the input voltage based on the low potential side power supply voltage is input to the gate of the detection transistor. It will be. Since the on-resistance of the detection transistor increases when the boosted voltage rises to the vicinity of the low potential side power supply voltage, it can be detected that the boosted voltage is abnormal when the boosted voltage rises to the vicinity of the low potential side power supply voltage.

  In the aspect of the invention, the boosted voltage may be a substrate voltage of a circuit device.

  For example, when the substrate is a P substrate, the lowest voltage among the voltages generated by the power supply circuit is set as the substrate voltage. When an abnormality occurs in the power supply and a current flows through the parasitic bipolar of the substrate, the current often flows into the substrate voltage, which is the lowest voltage. Therefore, it is possible to detect an abnormality in the power supply by detecting an abnormality in the boost voltage that is the substrate voltage.

  In one embodiment of the present invention, the control circuit may include a control circuit that controls the power supply circuit, and the control circuit may re-execute a startup sequence of the power supply circuit when an abnormality in the boosted voltage is detected.

  When the start-up sequence is re-executed, the operation of the power supply circuit including the booster circuit is temporarily stopped. Therefore, no current is supplied from the booster circuit to the parasitic transistor on the substrate, and the power supply can be recovered from the abnormality.

  In one embodiment of the present invention, a driving circuit for driving a display panel based on power supplied from the power supply circuit may be included.

  According to another aspect of the invention, there is provided an electro-optical device including the circuit device described above and a display panel.

  Another aspect of the invention relates to an electronic device including the circuit device described in any of the above.

2 shows a configuration example of a circuit device and a first detailed configuration example of an abnormality detection circuit. Operation | movement explanatory drawing of an abnormality detection circuit. The 2nd detailed structural example of an abnormality detection circuit. The 1st structural example of a driver. FIG. 5A shows a second configuration example of the driver. FIG. 5B is a timing chart of the second configuration example of the driver. FIG. 6A shows a third configuration example of the driver. FIG. 6B is a timing chart of the third configuration example of the driver. 10 shows a configuration example of a jth booster circuit. FIG. 8A shows a fourth configuration example of the driver. FIG. 8B shows a fifth configuration example of the driver. A variation of the driver. 2 shows a detailed configuration example of a power supply circuit. A configuration example of a driver to which a power supply circuit is applied. Power supply circuit startup sequence. Configuration examples of electro-optical devices and electronic devices.

  Hereinafter, preferred embodiments of the present invention will be described in detail. The present embodiment described below does not unduly limit the contents of the present invention described in the claims, and all the configurations described in the present embodiment are indispensable as means for solving the present invention. Not necessarily.

1. Circuit Device, Anomaly Detection Circuit As described above, a driver that drives a display panel generates a plurality of voltages by a power supply circuit, and operates a circuit such as a source driver by the plurality of voltages. For example, as will be described later with reference to FIGS. 10 and 11, the power supply circuit 110 of the driver 100 uses the system power supply voltages VDD and VSS supplied from the system power supply 210, the power supply voltages VDDHSP and VDDHSN of the source driver 120, and the common voltage VCOM. Is generated.

  These voltages are supplied to each node or substrate of the transistor in each circuit (that is, to the P-type / N-type diffusion layer, etc.). As long as each voltage maintains a predetermined magnitude relationship, Since a reverse voltage is applied to the PN junction in the substrate, the parasitic bipolar is not turned on. However, when the magnitude relation of the voltage is broken for some reason, the parasitic bipolar transistor is turned on, and a current path may be generated between the voltages generated by the power supply circuit. When such a current path is maintained, the voltage on the side from which the current is drawn decreases and the voltage on the side into which the current flows increases, so that the voltage generated by the power supply circuit is not a predetermined voltage. Get stuck.

  As a factor for turning on the parasitic bipolar, for example, noise or garbled register values can be assumed. For example, in the case of in-vehicle use, there is a noise generation source such as an engine, so that the environment is very noisy. If such noise appears in the voltage generated by the driver's power supply circuit, the noise may turn on the parasitic bipolar and cause the power supply to get stuck. In addition, when the register value data is garbled due to noise or the like, the power supply circuit is set so as not to occur in a normal use situation, and the PN junction may become a forward voltage. For example, when the power of the driver is turned off, the charge of the capacitor holding each voltage generated by the power supply circuit is shorted to the ground and discharged. If the register value that instructs discharge causes data corruption during normal operation of the driver, a part of the voltage generated by the power supply circuit is short-circuited to the ground. If it does so, the magnitude relationship of a voltage may collapse | crumble and it may cause a power supply jam.

  FIG. 1 shows a configuration example of a circuit device capable of detecting a power supply abnormality as described above and a first detailed configuration example of an abnormality detection circuit. The circuit device includes a power supply circuit having a booster circuit 160 and an abnormality detection circuit 130 that detects an abnormality of the boosted voltage VB generated based on the boosting operation of the booster circuit 160. The abnormality detection circuit 130 includes a detection transistor TDET. The detection transistor TDET is provided between a node of the first power supply voltage, which is one of the high-potential-side power supply voltage VDD and the low-potential-side power supply voltage VSS, and a node of the boost voltage VB. An input voltage VNB1 based on the second power supply voltage that is the other of the low potential power supply voltage VSS is input to the gate. Then, the abnormality detection circuit 130 detects an abnormality of the boost voltage VB based on a voltage change of one of the source and drain of the detection transistor TDET.

  In the following, the detection transistor TDET is an N-type transistor, the first power supply voltage is the high potential power supply voltage VDD, the second power supply voltage is the low potential power supply voltage VSS, and the abnormality detection circuit 130 detects A case where abnormality is detected based on a voltage change of the drain (node NB2) of the transistor TDET will be described as an example.

  The high-potential-side power supply voltage VDD and the low-potential-side power supply voltage VSS are not generated by the power supply circuit 110, but are power supply voltages supplied from, for example, a system power supply outside the circuit device. That is, the power supply voltages VDD and VSS are reliable voltages that do not vary even when an abnormality occurs in the boosted voltage VB and are constant voltages.

  The detection transistor TDET is provided between the node of the reliable first power supply voltage VDD and the node of the boosted voltage VB, and the input voltage VNB1 based on the reliable second power supply voltage VSS is input to the gate thereof. Thus, the abnormality of the boost voltage VB can be accurately detected. That is, since the first power supply voltage VDD and the second power supply voltage VSS do not change, the change in the drain voltage VNB2 of the detection transistor TDET is caused by the change in the boost voltage VB. That is, by detecting a change in the drain voltage VNB2 of the detection transistor TDET, an abnormality in the boosted voltage VB can be detected.

  Further, since abnormality of the boosted voltage VB can be self-detected by the abnormality detection circuit 130, a return operation can be performed based on the detection result, and the boost operation of the booster circuit 160 can be returned to a normal state. . For example, in the driver 100 described later in FIG. 4, the i-th boost circuit BCi corresponds to the boost circuit 160 of FIG. In the driver 100 of FIG. 4, when the abnormality detection circuit 130 detects an abnormality in the i-th boost voltage VBi, the j-th boost circuit BCj performs a low-capacity boost operation or the like to recover from the power supply jamming. . That is, when the jth booster circuit BCj is a current supply source for the parasitic bipolar transistor in the power supply stuck state, the current supply capability of the jth booster circuit BCj is lowered to reduce the parasitic bias. The on state of the polar can be released.

  In this embodiment, the abnormality detection circuit 130 includes a resistance element RC provided between the drain of the detection transistor TDET (one of the source and the drain) and the node of the first power supply voltage VDD.

  That is, the resistance element RC and the detection transistor TDET are connected in series between the node of the first power supply voltage VDD and the node of the boost voltage VB. The drain voltage VNB2 of the detection transistor TDET is a voltage divided by the resistance element RC and the on-resistance of the detection transistor TDET. When the boosted voltage VB changes, the source voltage of the detection transistor TDET changes, so that the on-resistance changes and the ratio of resistance division changes, so that the drain voltage VNB2 of the detection transistor TDET changes and an abnormality of the boosted voltage VB is detected. Is possible.

  In the present embodiment, the second transistor TB2 is provided between the source of the detection transistor (the other of the source and the drain) and the node of the boosted voltage VB, and the drain and the gate are connected. For example, the second transistor TB2 is an N-type transistor.

  Thus, by providing the so-called diode-connected second transistor TB2 on the source side of the detection transistor TDET, the detection voltage for abnormality detection can be adjusted. Specifically, the boosted voltage VB is a voltage (negative voltage) lower than the second power supply voltage VSS, and the boosted voltage VB is a substrate voltage of the semiconductor substrate of the circuit device as will be described later. When the power supply is jammed, the boosted voltage VB, which is the substrate voltage, rises. However, since a diode (parasitic diode or the like) exists between the substrate and the second power supply voltage VSS, the boosted voltage VB rises. Up to about the second power supply voltage VSS. Therefore, the abnormality of the boost voltage VB is performed with a detection voltage that is slightly lower than the second power supply voltage VSS. At this time, the detection voltage can be lowered by providing the second transistor TB2, and an appropriate detection voltage can be set.

  Although the detection voltage can also be changed by changing the gate voltage of the detection transistor TDET, this gate voltage is related to the hysteresis characteristic and cannot be changed only for adjustment of the detection voltage. Therefore, the second transistor TB2 is provided to adjust the detection voltage.

  In this embodiment, the abnormality detection circuit 130 detects that the boost voltage VB is abnormal when the boost voltage VB exceeds the detection voltage. This detection voltage has a hysteresis characteristic.

  Specifically, the abnormality detection circuit 130 includes a buffer circuit BFB that buffers the voltage of the drain (one of the source and the drain) of the detection transistor TDET, a gate of the detection transistor TDET, and a node of the second power supply voltage VSS. A third transistor TB3 provided between the node of the first power supply voltage VDD and the gate of the detection transistor TDET, which is provided between the third transistor TB3 which is turned on / off based on the output (voltage VNB4) of the buffer circuit BFB. 1 resistor element RB1, and a second resistor element RB2 provided between the gate of the detection transistor TDET and the node of the second power supply voltage VSS and connected in parallel to the third transistor TB3.

  The buffer circuit BFB includes a first inverter (P-type transistor TB4, N-type transistor TB5) that receives the drain voltage VNB2 of the detection transistor TDET, and a second inverter IVB2 that receives the output of the first inverter. . Abnormality detection circuit 130 includes an inverter IVB2 that receives the output of buffer circuit BFB and outputs detection signal SDT.

  The operation of the abnormality detection circuit 130 will be described with reference to FIG. FIG. 2 is a simulation result of the drain voltage VNB2 and the gate voltage VNB1 of the detection transistor TDET when the boosted voltage VB is changed. For convenience of simulation, the boost voltage VB is changed along the time axis.

  First, the operation when changing from normal to abnormal will be described. Under normal conditions, the circuit operates in the vicinity of the boosted voltage VB = −10V. At this time, since the drain voltage VNB2 of the detection transistor TDET is lower than VSS = 0V, the output of the buffer circuit BFB is at a low level, and the transistor TB3 is off. The gate voltage VNB1 of the detection transistor TDET is determined by resistance division of the resistance elements RB1 and RB2.

  When the boosted voltage VB increases from −10 V (from the center of the drawing to the right), the source voltage of the detection transistor TDET increases accordingly, and the on-resistance of the detection transistor TDET increases. Thereby, the drain voltage VNB2 of the detection transistor TDET increases. When the boosted voltage VB becomes the detection voltage VD1, the detection transistor TDET is turned off, and the drain voltage VNB2 of the detection transistor TDET increases to the power supply voltage VDD. Then, the output of the buffer circuit BFB changes from the low level to the high level. That is, when the boost voltage VB exceeds the detection voltage VD1, it is detected that the boost voltage VB is abnormal.

  Next, the operation when returning from abnormality to normal will be described. As the boosted voltage VB decreases from VSS = 0V (from the left to the center of the drawing), the source voltage of the detection transistor TDET decreases accordingly. When the boosted voltage VB becomes the detection voltage VD2, the detection transistor TDET is turned on, and the drain voltage VNB2 of the detection transistor TDET becomes lower than VSS = 0V. Then, the output of the buffer circuit BFB changes from the high level to the low level. When the output of the buffer circuit BFB is at a high level, the transistor TB3 is on, and the gate voltage VNB1 of the detection transistor TDET is VSS = 0V. Since this is lower than the divided voltage of the resistance elements RB1 and RB2, the detection transistor TDET is not turned on unless the source voltage of the detection transistor TDET is lowered. That is, VD2 <VD1, and the detected voltage has a hysteresis characteristic.

  FIG. 3 shows a second detailed configuration example of the abnormality detection circuit 130. In this configuration example, the abnormality detection circuit 130 is provided between the drain (one of the source and the drain) of the detection transistor TDET and the node of the first power supply voltage VDD, and the input voltage VNB1 is input to the gate. 1 transistor TB1. In addition, the same code | symbol is attached | subjected about the component similar to a 1st detailed structural example, and description is abbreviate | omitted suitably.

  The operation is basically the same as in the first detailed configuration example. That is, the on-resistance of the first transistor TB1 corresponds to the resistance element RC in the first detailed configuration example. The drain voltage VNB2 of the detection transistor TDET is determined by resistance division of the on-resistance of the first transistor TB1 and the on-resistance of the detection transistor TDET. Drain voltage VNB2 rises, the output of the buffer circuit BFB is inverted, and an abnormality is detected.

2. First Configuration Example of Driver Next, a circuit device capable of self-recovering from a power supply abnormality to a normal state when an abnormality in the boosted voltage is detected will be described. Hereinafter, a case where the circuit device is a driver will be described as an example, but the present invention can be applied to any circuit device including a power supply circuit having a booster circuit.

  FIG. 4 shows a first configuration example of the driver. The driver 100 in FIG. 4 includes a power supply circuit 110 having first to nth booster circuits BC1 to BCn (n is an integer of n ≧ 2), and a drive circuit 120 that operates based on the power supplied from the power supply circuit 110. (Circuit in a broad sense) and an anomaly detection circuit 130. The booster circuit 160 in FIG. 1 corresponds to the i-th booster circuit BCi in FIG.

  The abnormality detection circuit 130 detects an abnormality of the i-th boosted voltage VBi generated based on the boosting operation of the i-th boost circuit BCi (i is an integer of 1 ≦ i ≦ n). The j-th boost circuit BCj (j is an integer of 1 ≦ j ≦ n and j ≠ i) has a lower current supply capability than the normal boost operation when an abnormality of the i-th boost voltage VBi is detected. The capacity boosting operation is performed or the boosting operation is stopped.

  Specifically, the power supply circuit 110 generates a plurality of power supplies based on the first to nth boosted voltages VB1 to VBn generated by the first to nth booster circuits BC1 to BCn. For example, the power supply circuit 110 may further include a plurality of regulators that regulate the boosted voltages VB1 to VBn generated by the first to nth booster circuits BC1 to BCn. The outputs of the plurality of regulators or the first to nth boosted voltages are output as power supplies.

  Each booster circuit of the first to nth booster circuits BC1 to BCn is, for example, a charge pump circuit that performs a boosting operation by a switched capacitor operation. Alternatively, a switching regulator that performs a step-up operation by PWM driving of the inductor may be used. Each booster circuit generates a boosted voltage by boosting a system voltage supplied from the outside of the driver 100, a boosted voltage generated by a booster circuit other than itself, or a regulator output. Here, “boost” refers not only to generating a positive (or negative) boosted voltage of the same sign from a positive (or negative) input voltage, but also from a positive (or negative) input voltage of a negative ( Or the case of generating a positive boosted voltage.

  The abnormality detection circuit 130 detects that the i-th boost voltage VBi is an abnormal (abnormal) voltage and outputs the detection signal SDT to the j-th boost circuit BCj. For example, since the i-th boosted voltage VBi is considered to be within a predetermined voltage range in the normal state, it is determined that the i-th boosted voltage VBi is outside the predetermined voltage range (for example, a predetermined voltage or higher as described later). Detect as an abnormal state. In response to the detection signal SDT becoming active, the j-th boost circuit BCj performs the low-capacity boost operation or stops the boost operation.

  The low-capacity boosting operation is a boosting operation in which the current supply capability for the load is reduced. In other words, if the maximum output current that allows the booster circuit to maintain the boosted voltage at the specified voltage is the current supply capability, the boosted voltage is maintained at the specified voltage with a lower output current than the normal boosting operation in the low-capacity boosting operation. become unable. For example, in the case of a charge pump circuit, the current supply capability can be changed by changing the size (ON resistance) of the switch element of the switched capacitor. For example, the low-capacity boosting operation can be realized by the boosting operation performed by the soft start transistor of FIG. The normal boosting operation is an operation with the original current supply capability of the boosting circuit, for example, a boosting operation performed by a transistor for normal boosting operation in the boosting circuit of FIG.

  Stopping the boost operation is a state where the boost circuit does not perform the boost operation, for example, a state where the charge pump circuit or the switching regulator stops the switching operation. In this state, the operation stops in any one of a plurality of phases repeated in the switching operation, or the output of the booster circuit is set to a high impedance state.

  As described above, the abnormality detection circuit 130 detects the abnormality of the i-th boosted voltage VBi, so that the driver 100 can self-detect the abnormality of the boosted voltage. Then, when the abnormality of the i-th boosted voltage VBi is detected by the abnormality detection circuit 130, the j-th booster circuit BCj performs the low-capacity boosting operation or stops the boosting operation, thereby bringing the boosted voltage into a normal state. It becomes possible to return.

  In other words, the power supply is stuck due to a current flowing between the power supplies generated by the power supply circuit 110 via the parasitic bipolar in the substrate of the driver 100. Since the power supply circuit 110 generates the power supply voltage based on the boosted voltage, the supply source of the current flowing through the parasitic bipolar is the booster circuit. As long as sufficient current is supplied to the parasitic bipolar, the on state of the parasitic bipolar is maintained. Therefore, when the booster circuit that is the current supply source performs the low-capacity boosting operation or stops the boosting operation, the on-state of the parasitic bipolar is released, and the power supply can be released.

3. Second and Third Configuration Examples of Driver FIGS. 5A and 6A show second and third configuration examples of the driver 100. 5A and 6A, a part of the booster circuit and the driver circuit 120 are not shown. FIGS. 5B and 6B show timing charts of the second and third configuration examples.

  As shown in FIGS. 5B and 6B, the j-th boost circuit BCj performs the low-capacity boost operation or boost operation during the period in which the abnormality of the i-th boost voltage VBi is detected. Is stopped, and when the abnormality of the i-th boosted voltage VBi is not detected, the normal boosting operation is resumed.

  In the example of FIGS. 5B and 6B, the period in which the abnormality of the i-th boosted voltage VBi is detected is a period in which the detection signal SDT is at the high level (active). The case where the abnormality of the boosted voltage VBi is not detected is when the detection signal SDT is changed from the high level to the low level (inactive).

  As described above, in the present embodiment, the i-th boosted voltage can be returned to the normal state by the j-th boost circuit BCj performing the low-capacity boosting operation or stopping the boosting operation. Since the abnormality is not detected when the i-th boosted voltage returns to the normal state, the j-th booster circuit BCj can resume normal boosting operation as a trigger, and the operation of the booster circuit and the boosted voltage are changed to the normal state. Can be restored. This return operation is completed in the driver 100, and it is not necessary for the user to turn off the power switch. For example, in an in-vehicle application, even if an abnormality occurs in the power supply of the driver 100, it may be difficult to stop and turn off the engine. Therefore, it is desirable that the display can be restored by self-recovery from the power supply abnormality.

  In this embodiment, the i-th boosted voltage VBi is the substrate voltage of the driver 100. The abnormality detection circuit 130 detects an abnormality in the substrate voltage.

  That is, the driver 100 is formed of an integrated circuit device, and the voltage set on the semiconductor substrate of the integrated circuit device is the substrate voltage. For example, when the semiconductor substrate is P-type, the lowest voltage among the power supplies generated by the power supply circuit 110 is set as the substrate voltage. For example, in the power supply circuit of FIG. 10 described later, the voltage VEE generated by the booster circuit BC4 is the substrate voltage.

  When the semiconductor substrate is P-type, since the substrate voltage is the lowest voltage, there is a high possibility that the current flowing in the parasitic bipolar will eventually flow into the substrate in the case of power supply abnormality. When such an abnormal current flows into the substrate, the substrate voltage rises, so that the substrate voltage abnormality can be detected by detecting the potential.

  Specifically, as shown in FIGS. 5B and 6B, the abnormality detection circuit 130 determines that the i-th boosted voltage VBi is abnormal when the i-th boosted voltage VBi exceeds the detection voltage VD1. It detects that it is. This detection voltage has a hysteresis characteristic. That is, when the detection is not performed, the detection voltage VD2 (<VD1) different from the detection voltage VD1 is used.

  Thus, by detecting that the i-th boosted voltage VBi exceeds the detection voltage VD1, it is possible to detect that the substrate voltage has increased due to the power supply being stuck. Since the i-th boosted voltage VBi is considered to fluctuate within a predetermined range in a normal operation state (that is, a state where the power supply generated by the power supply circuit 110 is normal), the detection voltage VD1 is set outside the predetermined range. Alternatively, if it is known how much the i-th boosted voltage VBi will be (for example, experimentally known) when the power supply is stuck, the detection voltage VD1 is set to that voltage.

  In the second configuration example shown in FIG. 5A, the i-th boost voltage VBi is a voltage generated based on the j-th boost voltage VBj generated based on the boost operation of the j-th boost circuit BCj. . Then, as shown in FIG. 5B, the j-th boost circuit BCj performs the low-capacity boost operation when the abnormality of the i-th boost voltage VBi is detected, and the abnormality of the i-th boost voltage VBi is not detected. When it is detected, the normal boosting operation is resumed.

  Specifically, the power supply circuit 110 includes an i-th boost circuit BCi, a j-th boost circuit BCj, and a regulator RGA. The regulator RGA generates a voltage VGA from the j-th boosted voltage VBj, and the i-th boost circuit BCi boosts the voltage VGA to generate the i-th boosted voltage VBi. The regulator RGA is, for example, a linear regulator, and regulates the jth boosted voltage VBj to a voltage VGA that is a predetermined multiple of the reference voltage. For example, in the power supply circuit of FIG. 10 described later, the first booster circuit BC1 corresponds to the jth booster circuit BCj, the regulator RG8 corresponds to the regulator RGA, and the fourth booster circuit BC4 corresponds to the ith booster circuit BCi. Correspond.

  In such a configuration, the output voltage VGA of the regulator RGA is necessary for the i-th boosted voltage VBi to recover from the abnormal state. That is, the jth boosted voltage VBj that is the input voltage of the regulator RGA needs to be generated. Therefore, in the configuration of FIG. 5A, the j-th booster circuit BCj performs a low performance operation without stopping the boosting operation in the abnormal state, and the output of the regulator RGA to the i-th booster circuit BCi also in the abnormal state. Supply voltage VGA. As a result, the power supply jam can be eliminated and the i-th boosted voltage VBi can be self-recovered to a normal voltage.

  In the third configuration example shown in FIG. 6A, the i-th boost voltage VBi is generated based on the boost operation of the k-th boost circuit (k is an integer of 1 ≦ k ≦ n, k ≠ i, j). The generated voltage is based on the kth boosted voltage VBk. As shown in FIG. 6B, the j-th boost circuit BCj stops the boost operation when the abnormality of the i-th boost voltage VBi is detected.

  Specifically, the power supply circuit 110 includes an i-th boost circuit BCi, a j-th boost circuit BCj, a k-th boost circuit BCk, and a regulator RGB. The regulator RGB generates a voltage VGB from the kth boosted voltage VBk, and the i-th booster circuit BCi boosts the voltage VGB to generate the i-th boosted voltage VBi. The regulator RGB is, for example, a linear regulator, and regulates the kth boosted voltage VBk to a voltage VGB obtained by multiplying the reference voltage by a predetermined value. For example, in the power supply circuit of FIG. 10 described later, the second and third booster circuits BC2 and BC3 correspond to the jth booster circuit BCj, the first booster circuit BC1 corresponds to the kth booster circuit BCk, and the regulator RG8 corresponds to the regulator RGB, and the fourth booster circuit BC4 corresponds to the i-th booster circuit BCi.

  In such a configuration, the i-th boost voltage VBi can be recovered from the abnormal state even if the j-th boost voltage VBj is not generated. Therefore, in the configuration of FIG. 6A, the j-th boost circuit BCj stops the boost operation in an abnormal state. As a result, the j-th boosted voltage VBj is not generated in an abnormal state, but it is possible to self-recover from the power supply jamming as long as the i-th boosted circuit BCi can generate the i-th boosted voltage VBi. It becomes.

  In the present embodiment, the jth booster circuit BCj is the booster circuit having the highest current supply capability among the first to nth booster circuits BC1 to BCn.

  The power supply jamming is a state in which the on state of the parasitic bipolar is maintained, but a current sufficient to maintain the on state must be supplied to the parasitic bipolar. For this reason, it is considered that, in the output of the booster circuit having a small current supply capability, even if the parasitic bipolar is turned on, the on-state is naturally eliminated. Therefore, the boosting operation of the booster circuit having a high current supply capability for maintaining the parasitic bipolar on state may be reduced or stopped.

  For example, in the power supply circuit of FIG. 10, the first booster circuit BC1 is the booster circuit having the highest current supply capability. Since the first booster circuit BC1 is provided with a plurality of regulators and booster circuits as subsequent circuits, and it is necessary to supply output current and consumption current of these regulators and booster circuits, the first booster circuit BC1 The current supply capacity is the maximum. Even if the parasitic bipolar transistor is turned on at the end of the regulator or booster circuit at the subsequent stage of the first booster circuit BC1, the current supply of the first booster circuit BC1 that is the current supply source at the preceding stage is narrowed or stopped. , Can recover from the power plug.

  In the present embodiment, the drive circuit 120 drives the display panel 200 (electro-optical panel) based on the jth boosted voltage VBj generated based on the boosting operation of the jth booster circuit BCj.

  The drive circuit 120 is a source driver that drives the source lines of the display panel. Since the source driver needs to drive the pixel capacitance at a high speed, it is a circuit that consumes a large amount of current in the driver 100. Therefore, when the power supply of the drive circuit 120 is generated based on the jth boosted voltage VBj, the jth boosted voltage VBj has a large current supply capability. Since the j-th boost circuit BCj having such a large current supply capability can be a current supply source for the parasitic bipolar, it can be recovered from the power supply jamming by reducing or stopping the boost operation. .

  For example, in the power supply circuit of FIG. 10, the output voltages VDDHSP, VDDRMP, VDDHSN, and VDDRMN of the regulators RG5, RG7, RG11, and RG12 are the source driver power supply voltages. That is, the first booster circuit BC1 and the third booster circuit BC3 correspond to the jth booster circuit BCj.

  Note that in the power supply circuit of FIG. 10, the second booster circuit BC2, the fourth booster circuit BC4, and the fifth booster circuit BC5 may perform the low-capacity boosting operation or stop the boosting operation when the power supply is stuck. .

4). Booster Circuit FIG. 7 shows a configuration example of a jth booster circuit BCj capable of a low-capacity boosting operation. FIG. 7 shows a configuration example when the j-th boost circuit BCj is a charge pump circuit.

  The j-th boost circuit BCj includes boost transistors TA3 and TA4 for normal boost operation and boost transistors TA5 and TA6 for soft start. In the low-capacity boosting operation, the boosting operation is performed by the soft-start boosting transistors TA5 and TA6.

  More specifically, the j-th boost circuit BCj includes first to fourth transistors TA1 to TA4 connected in series, and fifth and sixth transistors connected in parallel to the third and fourth transistors TA3 and TA4. Transistors TA5 and TA6. In the normal boosting operation, the first to fourth transistors TA1 to TA4 are turned on / off, and in the low capacity boosting operation, the third and fourth transistors TA3 and TA4 are turned off. The soft start of the boosting operation is performed using the first and second transistors TA1 and TA2 and the fifth and sixth transistors TA5 and TA6.

  The transistors TA1 to TA3 and TA5 are P-type transistors, and the transistors TA4 and TA6 are N-type transistors. In a normal boost operation, the transistors TA2 and TA4 are turned on in the first period (first phase), the transistors TA1 and TA3 are turned off, one end of the capacitor CA is connected to the ground voltage VSS, and the other end of the capacitor CA. Is connected to the input voltage VIN. In the second period (second phase), the transistors TA2 and TA4 are turned off, the transistors TA1 and TA3 are turned on, one end of the capacitor CA is connected to the input voltage VIN, and the other end of the capacitor CA is connected via the transistor TA. The output voltage VQ = 2 × VIN is output. The transistors TA5 and TA6 are off in both the first period and the second period. Alternatively, soft start transistors TA5 and TA6 may be used in combination in a normal boosting operation. That is, the transistor TA6 may be turned on and the transistor TA5 may be turned off in the first period, the transistor TA5 may be turned on, and the transistor TA6 may be turned off in the second period. In the low-capacity boosting operation, the transistors TA2 and TA6 are turned on in the first period, the transistors TA1 and TA5 are turned off, the transistors TA2 and TA6 are turned off in the second period, and the transistors TA1 and TA5 are turned on.

  The sizes of boost transistors TA3 and TA4 for soft start (for example, channel width W / channel width W of channel length L) are smaller than the sizes of boost transistors TA5 and TA6 for normal boost operation. Therefore, the soft-start boost transistors TA3 and TA4 have higher on-resistance, and the current supply capability of the j-th boost circuit BCj is reduced by performing a boost operation with the transistors TA3 and TA4. The soft-start boost transistors TA3 and TA4 are provided to suppress an inrush current when starting the boost operation when the power supply circuit 110 is activated. By using the soft start circuit originally provided in this way, it is possible to realize a low-capacity boosting operation when the power supply is stuck.

5. Fourth and Fifth Configuration Examples FIG. 8A shows a fourth configuration example of the driver 100. The fourth configuration example is a configuration example in the case where the j-th boost circuit BCj stops the boost operation when the power supply is stuck. Note that illustration of part of the driver circuit 120 and the booster circuit is omitted in FIG.

  The driver 100 includes a control circuit 140, a j-th boost circuit BCj, and an abnormality detection circuit 130. The jth booster circuit BCj includes an enable signal generator GEN, a booster clock generator CKG, and a booster BST.

  The booster BST is configured by the charge pump circuit described with reference to FIG. The step-up clock generation unit CKG generates a clock signal that drives the step-up unit BST. That is, a clock signal for controlling on / off of the transistors TA1 to TA6 constituting the boosting unit BST is generated corresponding to a normal boosting operation or a soft start operation (low-capacity boosting operation).

  The control circuit 140 outputs the enable signal EN and the soft start signal SFT to the j-th boost circuit BCj. The j-th boost circuit BCj performs a boost operation while the enable signal EN is active, and performs a soft start operation when the soft start signal SFT is active.

  The enable signal generation unit GEN generates a new enable signal ENA based on the enable signal EN from the control circuit 140 and the detection signal SDT from the abnormality detection circuit 130. When the enable signal EN is active and the abnormality detection circuit 130 detects an abnormality in the i-th boosted voltage VBi and the detection signal SDT becomes active, the enable signal generation unit GEN outputs an inactive enable signal ENA. To do. That is, the stop of the boosting operation is instructed to the jth booster circuit BCj when the power supply is stuck. For example, when the enable signal EN and the detection signal SDT are high active, the enable signal generation unit GEN includes an inverter that logically inverts the detection signal SDT, and an AND circuit that outputs a logical product of the output of the inverter and the enable signal EN. Composed.

  FIG. 8B shows a fifth configuration example of the driver 100. The fifth configuration example is a configuration example in the case where the j-th boost circuit BCj performs the low-capacity boost operation when the power supply is stuck. Note that illustration of part of the driver circuit 120 and the booster circuit is omitted in FIG.

  The driver 100 includes a control circuit 140, a j-th boost circuit BCj, and an abnormality detection circuit 130. The jth booster circuit BCj includes a soft start signal generator GSF, a booster clock generator CKG, and a booster BST.

  The soft start signal generation unit GSF generates a new soft start signal SFTA based on the soft start signal SFT from the control circuit 140 and the detection signal SDT from the abnormality detection circuit 130. When the soft start signal SFT is inactive and the abnormality detection circuit 130 detects the abnormality of the i-th boosted voltage VBi and the detection signal SDT becomes active, the soft start signal generation unit GSF generates an active soft start signal. Outputs SFTA. That is, the soft start operation (low-capacity boosting operation) is instructed to the jth booster circuit BCj when the power supply is stuck. For example, when the soft start signal SFT and the detection signal SDT are high active, the enable signal generation unit GEN is configured by a logical sum circuit that outputs a logical sum of the detection signal SDT and the soft start signal SFT.

6). Modified Example FIG. 9 shows a modified example of the driver 100. In this modification, when an abnormality of the boost voltage (i-th boost voltage VBi) is detected, the startup sequence of the power supply circuit 110 is re-executed.

  Specifically, the abnormality detection circuit 130 outputs a detection signal SDT to the control circuit 140. When the detection signal SDT becomes active, the control circuit 140 temporarily stops the operation of the power supply circuit 110, and then restarts the power supply circuit 110. The activation sequence is a sequence for controlling the operation timing of each part of the power supply circuit 110. As will be described later with reference to FIG. 12, for example, the timing for starting the boosting operation of the first to nth boosting circuits BC1 to BCn, the timing for starting and stopping the soft start, and the operation of the regulator are started (or the output is enabled). Control timing etc.

  As described above, not only the low-capacity boosting operation and the stoppage of the boosting operation but also the self-recovery from the power supply jamming can be performed by re-executing the startup sequence. That is, when the start-up sequence is re-executed, the operation of the power supply circuit including the booster circuit is temporarily stopped, so that no current is supplied to the parasitic transistor, and the power supply can be recovered from being stuck.

7). Power Supply Circuit FIG. 10 shows a detailed configuration example of the power supply circuit 110. FIG. 11 shows a configuration example of the driver 100 to which the power supply circuit 110 of FIG. 10 is applied.

  The driver 100 in FIG. 11 includes a power supply circuit 110, a source driver 120 (drive circuit), a gate driver 150, and a control circuit 140. The source driver 120 (data driver) is a circuit that drives a source line (data line) of the display panel 200, and includes, for example, a gradation voltage generation circuit, a D / A conversion circuit, a source amplifier, and the like. The gate driver 150 (scan driver) is a circuit that drives the gate lines (scan lines) of the display panel 200, and includes, for example, a level shifter, a buffer, and the like. The control circuit 140 includes, for example, an interface circuit that communicates with the display controller 300, a line latch that latches image data transmitted from the display controller 300, a timing controller that controls display control timing, and the like. For example, the control circuit 140 includes a gate array or the like.

  The power supply circuit 110 in FIG. 10 includes first to fifth booster circuits BC1 to BC5 and first to thirteenth regulators RG1 to RG13. For example, the first to fifth booster circuits BC1 to BC5 are charge pump circuits, and the first to thirteenth regulators RG1 to RG13 are linear regulators. In FIG. 10, the positional relationship between the voltages in the vertical direction of the drawing represents the approximate relationship between the voltages. For example, VDDL, VLDO, etc. are voltages between VDD and VSS, VOUTM, VOUT3, etc. are voltages lower than VSS (negative voltage), and VOUT, etc. are voltages higher than VDD.

  Regulators RG1, RG2, and RG3 step down the power supply voltage VDD to generate voltages VDDL, VLDO1, and VLDO2. As shown in FIG. 10, the voltage VDDL is a power supply voltage of the control circuit 140 (logic circuit).

  The booster circuit BC1 doubles the voltage VLDO1 with the voltage VSS as a reference to generate the voltage VOUT. Regulators RG4, RG5, RG6, RG7, RG8, and RG9 step down the voltage VOUT to generate voltages VREG, VDDHSP, VDDRHP, VDDRMP, VOFREG, and VONREG. The regulator RG4 generates a voltage VREG with reference to an output voltage of a band gap circuit (not shown). The other regulators RG1 to RG3 and RG5 to RG13 output each voltage based on the voltage VREG. As shown in FIG. 10, the voltages VDDHSP and VDDRMP are positive power supply voltages of the source driver 120 (power supply voltages used for positive electrode driving of dot inversion driving). The voltage VDDRHP is a power supply voltage of the gradation voltage generation circuit.

  The booster circuit BC2 inverts the voltage VLDO2 with respect to the voltage VSS to generate a negative voltage VOUTM. The regulator RG10 generates a voltage VCOM from the voltage VLDO2 and the voltage VOUTM. The voltage VCOM is a common voltage when driving the source line of the display panel 200.

  The booster circuit BC3 generates a negative voltage VOUT3 by inverting and boosting the voltage VDD four times with respect to the voltage VSS. The regulator RG11 steps down the voltage VOUT3 to generate the voltage VDDHSN, and the regulator RG12 steps down the voltage VDDHSN to generate the voltage VDDRMN. As shown in FIG. 10, the voltages VDDHSN and VDDRMP are negative power supply voltages of the source driver 120 (power supply voltages used for negative drive of dot inversion drive).

  The booster circuit BC4 inverts and boosts the voltage VOFREG three times with respect to the voltage VSS, and generates a negative voltage VEE. The voltage VEE is a substrate voltage of the semiconductor substrate (P-type substrate) of the driver 100. The regulator RG13 steps down the voltage VEE to generate the voltage VGL. As shown in FIG. 10, the voltage VGL is a negative power supply voltage of the gate driver 150.

  The booster circuit BC5 generates the voltage VDDHG = VONREG × 2-VGL from the voltage VONREG and the voltage VGL. As shown in FIG. 10, the voltage VDDHG is a positive power supply voltage of the gate driver 150.

  FIG. 12 shows a startup sequence of the power supply circuit 110 executed by the control circuit 140. The activation sequence is not limited to that shown in FIG. 12, and for example, the boosting operations of the booster circuits BC1 to BC5 may be started simultaneously. For example, the activation sequence may be set by the user by register setting.

  As shown in FIG. 12, when the register value DISON for instructing activation of the power supply circuit 110 is activated by the display controller (processing unit) outside the driver 100, the control circuit 140 starts the activation sequence of the power supply circuit 110. . For example, the execution period of the activation sequence is 6 frames F1 to F6. The regulator RG1 is turned on together with the band gap circuit when the driver 100 is powered on.

  In the startup sequence, first, at the start of the second frame F2, the enable signal of the booster circuits BC1 to BC3 is activated to start the boosting operation. Further, the regulators RG1 to RG4 are turned on. During the second to fifth frames F2 to F5, the soft start signals of the booster circuits BC1 to BC3 are activated to perform the soft start operation. Next, at the start of the third frame F3, the enable signals of the regulators RG5 to 7, 11 and 12 are activated to turn on the operation. Up to the third frame F3, the primary to tertiary boosting systems rise, and the reference voltage and common voltage of the regulator and the power supply voltage of the source driver are output.

  At the start of the third frame F3, the enable signal of the regulator RG8 is activated to turn on the operation, and the enable signal of the booster circuit BC4 is activated to start the boost operation. Next, at the start of the fourth frame F4, the enable signal of the regulator RG13 is activated to turn on the operation. Further, the enable signal of the regulator RG9 is activated to turn on the operation, and the enable signal of the booster circuit BC5 is activated to start the boosting operation. Up to the fourth frame F4, the fourth-order and fifth-order boost systems rise, and the gate driver power supply voltage and the substrate voltage are output.

  Next, during the fifth frame F5 (before the start of the sixth frame F6), the enable signal of the regulator RG10 is activated to turn on the operation. A common voltage is output in the fifth frame. At the start of the sixth frame F6, the soft start operations of the booster circuits BC1 to BC3 are finished and the normal boosting operation is started, and at the end of the sixth frame F6, the start-up sequence is finished.

  In the re-execution of the startup sequence described with reference to FIG. 6, when the detection signal SDT from the abnormality detection circuit 130 becomes active, the control circuit 140 deactivates the register value DISON and activates the register value DISON again. The start sequence is executed again.

8). Electro-Optical Device and Electronic Device FIG. 13 shows a configuration example of an electro-optical device and an electronic device to which the driver 100 of this embodiment can be applied. As the electronic device of the present embodiment, various electronic devices equipped with a display device such as a projector, a television device, an information processing device (computer), a portable information terminal, a car navigation system, and a portable game terminal are assumed. it can.

  The electronic device illustrated in FIG. 13 includes an electro-optical device 350, a display controller 300 (host controller, first processing unit), a CPU 310 (second processing unit), a storage unit 320, a user interface unit 330, and a data interface unit 340. The electro-optical device 350 includes a driver 100 and a display panel 200.

  The display panel 200 is, for example, a matrix type liquid crystal display panel. Alternatively, the display panel 200 may be an EL (Electro-Luminescence) display panel using self-luminous elements. For example, a flexible substrate is connected to the display panel 200, the driver 100 is mounted on the flexible substrate, and the electro-optical device 350 is configured. Note that the driver 100 and the display panel 200 may not be configured as the electro-optical device 350 but may be incorporated into an electronic apparatus as individual components. For example, a flexible substrate for drawing out wiring is connected to the display panel 200, the driver 100 is mounted on a rigid substrate together with the display controller 300 and the like, and the display panel 200 is mounted by connecting the flexible substrate to the rigid substrate. Good.

  The user interface unit 330 is an interface unit that accepts various operations from the user. For example, it includes a button, a mouse, a keyboard, a touch panel mounted on the display panel 200, and the like. The data interface unit 340 is an interface unit that inputs and outputs image data and control data. For example, a wired communication interface such as a USB or a wireless communication interface such as a wireless LAN. The storage unit 320 stores the image data input from the data interface unit 340. Alternatively, the storage unit 320 functions as a working memory for the CPU 310 and the display controller 300. The CPU 310 performs control processing of various parts of the electronic device and various data processing. The display controller 300 performs control processing for the driver 100. For example, the display controller 300 converts the image data transferred from the data interface unit 340 or the storage unit 320 into a format that can be accepted by the driver 100, and outputs the converted image data to the driver 100. The driver 100 drives the display panel 200 based on the image data transferred from the display controller 300.

  Although the present embodiment has been described in detail as described above, it will be easily understood by those skilled in the art that many modifications can be made without departing from the novel matters and effects of the present invention. Accordingly, all such modifications are intended to be included in the scope of the present invention. For example, a term described at least once together with a different term having a broader meaning or the same meaning in the specification or the drawings can be replaced with the different term in any part of the specification or the drawings. All combinations of the present embodiment and the modified examples are also included in the scope of the present invention. Further, the configurations and operations of the power supply circuit, the abnormality detection circuit, the circuit device, the electro-optical device, and the electronic device are not limited to those described in this embodiment, and various modifications can be made.

100 drivers, 110 power supply circuits, 120 source drivers,
120 drive circuit, 130 abnormality detection circuit, 140 control circuit,
150 gate driver, 160 booster circuit, 200 display panel,
210 system power supply, 300 display controller, 310 CPU,
320 storage unit, 330 user interface unit,
340 data interface unit, 350 electro-optical device,
BCi ith booster circuit, BCj jth booster circuit, BCk kth booster circuit,
BFB buffer circuit, TDET detection transistor,
VB boost voltage, VBi i-th boost voltage, VBj j-th boost voltage,
VBk kth boost voltage, VD1, VD2 detection voltage,
VDD High-potential power supply voltage, VSS Low-potential power supply voltage

Claims (12)

A power supply circuit having a booster circuit;
An abnormality detection circuit for detecting an abnormality of the boosted voltage generated based on the boosting operation of the booster circuit;
Including
The abnormality detection circuit is
Provided between a node of a first power supply voltage, which is one of a high-potential-side power supply voltage and a low-potential-side power supply voltage, and a node of the boosted voltage; And having a detection transistor in which an input voltage based on the second power supply voltage as the other is input to the gate,
A circuit device, wherein an abnormality of the boosted voltage is detected based on a voltage change of one of a source and a drain of the detection transistor. In claim 1,
The abnormality detection circuit is
A circuit device comprising: a resistance element provided between the one of the source and the drain of the detection transistor and a node of the first power supply voltage. In claim 1,
The abnormality detection circuit is
A circuit device comprising: a first transistor provided between the one of the source and the drain of the detection transistor and a node of the first power supply voltage, the gate of which the input voltage is input to. In claim 2 or 3,
A circuit device comprising: a second transistor provided between the other of the source and drain of the detection transistor and a node of the boosted voltage, the drain and gate of which are connected. In any one of Claims 1 thru | or 4,
The abnormality detection circuit is
Detecting that the boosted voltage is abnormal when the boosted voltage exceeds a detection voltage;
The circuit device according to claim 1, wherein the detection voltage has a hysteresis characteristic. In claim 5,
The abnormality detection circuit is
A buffer circuit for buffering the one of the source and drain of the detection transistor;
A third transistor provided between the gate of the detection transistor and a node of the second power supply voltage and turned on / off based on an output of the buffer circuit;
A first resistance element provided between a node of the first power supply voltage and the gate of the detection transistor;
A second resistance element provided between the gate of the detection transistor and the node of the second power supply voltage and connected in parallel to the third transistor;
A circuit device comprising: In any one of Claims 1 thru | or 6.
The boosted voltage is a negative voltage,
The first power supply voltage is the high potential side power supply voltage,
The circuit device according to claim 1, wherein the second power supply voltage is the low-potential-side power supply voltage. In any one of Claims 1 thru | or 7,
The circuit device according to claim 1, wherein the boosted voltage is a substrate voltage of the circuit device. In any one of Claims 1 thru | or 8.
A control circuit for controlling the power supply circuit;
The control circuit includes:
A circuit device characterized by re-executing a startup sequence of the power supply circuit when an abnormality of the boosted voltage is detected. In any one of Claims 1 thru | or 9,
A circuit device comprising a drive circuit for driving a display panel based on power supplied from the power supply circuit. A circuit device according to claim 10;
A display panel;
An electro-optical device comprising:   An electronic apparatus comprising the circuit device according to claim 1.

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