Power management circuit, electronic control unit, and vehicle

Abstract

According to the present invention, a power management circuit has: a first terminal; a second terminal; a third terminal; a first step-down DC / DC converter configured to receive a first voltage applied to the first terminal; a fist linear regulator configured to receive a second voltage applied to the second terminal; a second linear regulator configured to receive a third voltage applied to the third terminal; and a control circuit for a step-up DC / DC converter configured to receive an output voltage of the first step-down DC / DC converter.

Description

Power management circuit, electronic control unit, and vehicle

[0001] The invention disclosed in this specification relates to a power management circuit, and an electronic control unit and a vehicle using the same.

[0002] 2. Description of the Related Art Power management circuits that manage a plurality of power supply circuits are known.

[0003] JP 2016-024561 A (FIG. 3)

[0004] In the power management circuit proposed in Patent Document 1, multiple power supply circuits share a common input voltage. When the multiple power supply circuits include a first LDO (Low Drop Output) that outputs a first output voltage and a second LDO that outputs a second output voltage lower than the first output voltage, the input voltage of the multiple power supply circuits must be higher than the first output voltage. In this case, the difference between the input voltage of the multiple power supply circuits and the second output voltage becomes large, resulting in large losses in the second LDO.

[0005] The power management circuit disclosed herein includes a first terminal, a second terminal, a third terminal, a first step-down DC / DC converter configured to receive a first voltage applied to the first terminal, a first linear regulator configured to receive a second voltage applied to the second terminal, a second linear regulator configured to receive a third voltage applied to the third terminal, and a control circuit for a step-up DC / DC converter configured to receive the output voltage of the first step-down DC / DC converter.

[0006] The electronic control unit disclosed in this specification includes a power management circuit having the above-described configuration and a microcontroller unit configured to be supplied with power from the power management circuit.

[0007] The vehicle disclosed in this specification has an electronic control unit having the above-described configuration.

[0008] According to the invention disclosed in this specification, the loss in the power management circuit can be reduced.

[0009] FIG. 1 is a diagram showing a first use example of the power management circuit. FIG. 2 is a schematic diagram for explaining a setting example in the first use example. FIG. 3 is a diagram showing a second use example of the power management circuit. FIG. 4 is a schematic diagram for explaining a first setting example in the second use example. FIG. 5 is a schematic diagram for explaining a second setting example in the second use example. FIG. 6 is a diagram showing a third use example of the power management circuit. FIG. 7 is a schematic diagram for explaining a setting example in the third use example. FIG. 8 is a diagram showing a fourth use example of the power management circuit. FIG. 9 is a schematic diagram for explaining a setting example in the fourth use example. FIG. 10 is a diagram showing a schematic configuration of an electronic control unit. FIG. 11 is an external view of a vehicle.

[0010] In this specification, a MOS (Metal Oxide Semiconductor) field effect transistor refers to a field effect transistor whose gate structure is composed of at least three layers: a layer made of a conductor or a semiconductor such as polysilicon with a low resistance value, an insulating layer, and a P-type, N-type, or intrinsic semiconductor layer. In other words, the gate structure of a MOS field effect transistor is not limited to a three-layer structure of a metal, an oxide, and a semiconductor.

[0011] <First Use Example of Power Management Circuit> Figure 1 is a diagram showing a first use example of a power management circuit 1. The power management circuit 1 has terminals T1 to T20, step-down DC / DC converters 11 and 12, LDOs 13 and 14, a tracker 15, a control circuit 16 for the step-up DC / DC converter, and a communication unit 17. The step-down DC / DC converter 11 is a primary power supply. The step-down DC / DC converter 12, the LDOs 13 and 14, and the tracker 15 are secondary power supplies that directly or indirectly use the output voltage of the primary power supply. The LDOs 13 and 14 are each an example of a linear regulator.

[0012] The power management circuit 1 is mounted on a one-chip semiconductor integrated circuit device. The one-chip semiconductor integrated circuit device is sealed with resin. Because the power management circuit 1 is integrated, it is sometimes called a PMIC (Power Management Integrated Circuit).

[0013] The step-down DC / DC converter 11 converts the voltage applied to a terminal T1 into a voltage VOUT1 in cooperation with an inductor L1 and a capacitor C1, which are external components. In this example, an input voltage VIN is applied to the terminal T1. The input voltage VIN may be, for example, the voltage output from a battery mounted on a vehicle.

[0014] The terminal T2 is a terminal for outputting the switch voltage output from the step-down DC / DC converter 11 to the inductor L1. The terminal T3 is a terminal for feeding back the voltage VOUT1 to the step-down DC / DC converter 11. A first end of the inductor L1 is connected to the terminal T2. A second end of the inductor L1 and a first end of the capacitor C1 are connected to the terminal T3. A second end of the capacitor C1 is connected to the ground potential.

[0015] If the high-side switching element in the step-down DC / DC converter 11 is an N-channel MOS field-effect transistor, the step-down DC / DC converter 11 may be configured to receive a bootstrap voltage output from a bootstrap circuit formed by external components.

[0016] The step-down DC / DC converter 12 converts the voltage applied to the terminal T4 into a voltage VOUT2 in cooperation with an inductor L2 and a capacitor C2, which are external components. In this example, the voltage VOUT1 is applied to the terminal T4.

[0017] The terminal T5 is a terminal for outputting the switch voltage output from the step-down DC / DC converter 12 to the inductor L2. The terminal T6 is a terminal for feeding back the voltage VOUT2 to the step-down DC / DC converter 12. A first end of the inductor L2 is connected to the terminal T5. A second end of the inductor L2 and a first end of the capacitor C2 are connected to the terminal T6. A second end of the capacitor C2 is connected to the ground potential.

[0018] If the high-side switching element in the step-down DC / DC converter 12 is an N-channel MOS field-effect transistor, the step-down DC / DC converter 12 may be configured to receive a bootstrap voltage output from a bootstrap circuit formed by external components.

[0019] The LDO 13 converts the voltage applied to terminal T7 into voltage VOUT3 in cooperation with capacitor C3, which is an external component. The LDO 13 is connected to a first end of capacitor C3 via terminal T8. A second end of capacitor C3 is connected to ground potential. In this example, voltage VOUT1 is applied to terminal T7. Unlike the configuration shown in FIG. 1 , terminals T4 and T7 may be combined into one common terminal and shared by the step-down DC / DC converter 12 and the LDO 13.

[0020] The LDO regulator 14, in cooperation with an external capacitor C4, converts the voltage applied to the terminal T9 into a voltage VOUT4. The LDO regulator 14 is connected to a first end of the capacitor C4 via a terminal T10. A second end of the capacitor C4 is connected to the ground potential. In this example, a voltage VOUT6 is applied to the terminal T9. Details of the voltage VOUT6 will be described later.

[0021] The tracker 15, in cooperation with an external capacitor C6, converts the voltage applied to the terminal T9 into a voltage VOUT5. A sensor provided outside the power management circuit 1 operates using the voltage VOUT5 output from the tracker 15 as a power supply voltage. The tracker 15 is connected to a first end of the capacitor C5 via the terminal T12. The second end of the capacitor C5 is connected to the ground potential. In this example, the voltage VOUT6 is applied to the terminal T9. Unlike the configuration shown in FIG. 1 , the LDO 14 and the tracker 15 may share a single terminal that combines the terminals T9 and T11.

[0022] The step-up DC / DC converter is configured by the control circuit 16 and external components for the step-up DC / DC converter, including an inductor L3, an N-channel MOS field-effect transistor Q1, a current sense resistor R1, a diode D1, and a capacitor C6.

[0023] A voltage VOUT1 is applied to a first end of inductor L3. A second end of inductor L3 is connected to the anode of diode D1 and the drain of N-channel MOS field-effect transistor Q1. The source of N-channel MOS field-effect transistor Q1 is connected to ground potential via current sense resistor R1. A first end of current sense resistor R1 is connected to the control circuit 16 of the step-up DC / DC converter via terminal T14. A second end of current sense resistor R1 is connected to the control circuit 16 of the step-up DC / DC converter via terminal T15. The control circuit 16 of the step-up DC / DC converter determines the source current of N-channel MOS field-effect transistor Q1 based on the potential difference across the current sense resistor R1. A voltage VOUT6 generated at the connection node between the cathode of diode D1 and the first end of capacitor C6 is fed back to the control circuit 16 of the step-up DC / DC converter via terminal T13. A second end of capacitor C6 is connected to ground potential. The gate of the N-channel MOS field effect transistor Q1 is connected to a control circuit 16 of the step-up DC / DC converter via a terminal T16. The control circuit 16 of the step-up DC / DC converter controls the switching of the N-channel MOS field effect transistor Q1 based on the source current of the N-channel MOS field effect transistor Q1 and a voltage VOUT6.

[0024] The communication unit 17 communicates with the outside via terminals T17 to T20. There are no particular limitations on the communication method of the communication unit 17, and the communication unit 17 may, for example, perform SPI (Serial Peripheral Interface) communication. The number of terminals connected to the communication unit 17 is not limited to four, and may be any appropriate number depending on the communication method of the communication unit 17. Communication by the communication unit 17 is used, for example, when various settings of the power management circuit 1 are executed from the outside.

[0025] Fig. 2 is a schematic diagram for explaining a setting example in the first use example, in which external components and the like are omitted from the illustration.

[0026] In the setting example shown in FIG. 2, the step-down DC / DC converter 11 converts the input voltage VIN to a voltage of 3.8V.

[0027] 2, the step-down DC / DC converter 12 converts a voltage of 3.8 V to a voltage of 1.2 V. In the setting example shown in FIG. 2, the LDO 13 converts a voltage of 3.8 V to a voltage of 3.3 V.

[0028] In the example shown in Fig. 2, the step-up DC / DC converter 18 is configured by the step-up DC / DC converter control circuit 16 and external components for the step-up DC / DC converter (see Fig. 1). In the example shown in Fig. 2, the step-up DC / DC converter 18 converts a voltage of 3.8 V to a voltage of 5.7 V.

[0029] 2, the LDO 14 converts a voltage of 5.7 V to a voltage of 5.0 V. In the setting example shown in FIG. 2, the tracker 15 converts a voltage of 5.7 V to a voltage of 5.0 V.

[0030] A linear regulator adjusts the output voltage by adjusting the on-resistance of the output transistor, so the greater the difference between the input voltage of the linear regulator and the output voltage of the linear regulator, the greater the loss in the linear regulator.

[0031] 2 , the output voltages of LDO 13 and LDO 14 are significantly different from each other. However, by supplying the output voltage of step-down DC / DC converter 11 to LDO 13 and the output voltage of step-up DC / DC converter 18 to LDO 14, the difference between the input voltage and output voltage of the LDOs 13 and 14 is reduced. Therefore, the power management circuit 1 can reduce losses in both LDOs 13 and 14. As a result, the power management circuit 1 can suppress heat generation despite having a configuration in which both the primary power supply and the secondary power supply are built into a single-chip semiconductor integrated circuit device.

[0032] In the example of settings shown in FIG. 2, the output voltage of the step-down DC / DC converter 11 is low, so there is no need to take measures against a temporary drop in the input voltage VIN due to, for example, cranking of the vehicle.

[0033] Furthermore, in the example setting shown in FIG. 2, the difference between the input voltage of the tracker 15 and the output voltage of the tracker 15 is small, so the power management circuit 1 can reduce the loss in the tracker 15.

[0034] 3 is a diagram showing a second use example of the power management circuit 1. The second use example differs from the first use example in that external components for the step-up DC / DC converter are not connected to the power management circuit 1 and voltage VOUT1 is applied to terminals T9 and T11 instead of voltage VOUT6, but is otherwise identical to the first use example.

[0035] 4 is a schematic diagram for explaining the first setting example in the second use example, in which external components and the like are omitted from the illustration.

[0036] In the first setting example of the second use example, the step-down DC / DC converter 11 converts the input voltage VIN to a voltage of 5.7V.

[0037] 4, the step-down DC / DC converter 12 converts a voltage of 5.7 V to a voltage of 1.2 V. In the setting example shown in FIG. 4, the LDO 13 converts a voltage of 5.7 V to a voltage of 5.0 V.

[0038] 4, the LDO 14 converts a voltage of 5.7 V to a voltage of 3.3 V. In the setting example shown in FIG. 4, the tracker 15 converts a voltage of 5.7 V to a voltage of 5.0 V.

[0039] The setting example shown in FIG. 4 is suitable when the load on the LDO 14 is small, that is, when the output current of the LDO 14 is small.

[0040] As a countermeasure against a temporary drop in input voltage VIN due to, for example, vehicle cranking, the following configuration may be employed: External components for a step-up DC / DC converter are connected to the power management circuit 1, and the output voltage of the step-up DC / DC converter is supplied to the step-down DC / DC converter 11. When the input voltage VIN drops, the step-down DC / DC converter 11 uses the output voltage of the step-up DC / DC converter instead of the input voltage VIN.

[0041] 5 is a schematic diagram for explaining a second setting example in a second use example, in which external components and the like are omitted from the illustration.

[0042] In the setting example shown in FIG. 5, the step-down DC / DC converter 11 converts the input voltage VIN to a voltage of 3.8V.

[0043] 5, the step-down DC / DC converter 12 converts a voltage of 3.8 V to a voltage of 1.2 V. In the setting example shown in FIG. 5, the LDO 13 converts a voltage of 3.8 V to a voltage of 3.3 V.

[0044] In the example setting shown in Fig. 5, the LDO 14 converts a voltage of 3.8 V to a voltage of 3.3 V. In the example setting shown in Fig. 5, the tracker 15 converts a voltage of 3.8 V to a voltage of 3.3 V.

[0045] The setting example shown in FIG. 5 is suitable when a high output voltage is not required.

[0046] In the setting example shown in FIG. 5, the output voltage of the step-down DC / DC converter 11 is low, so there is no need to take measures against a temporary drop in the input voltage VIN due to, for example, cranking of the vehicle.

[0047] 6 is a diagram showing a third use example of the power management circuit 1. The third use example differs from the first use example in that the input voltage VIN rather than the voltage VOUT1 is applied to the first end of the inductor L3, the voltage VOUT6 rather than the input voltage VIN is applied to the terminal T1, and the voltage VOUT1 rather than the voltage VOUT6 is applied to the terminals T9 and T11, but is otherwise the same as the first use example.

[0048] Fig. 7 is a schematic diagram for explaining a setting example in the third use example, in which external components and the like are omitted from the illustration.

[0049] 7, the step-up DC / DC converter 18 converts the input voltage VIN to a voltage of 6.4 V. The step-down DC / DC converter 11 converts the voltage of 6.4 V to a voltage of 5.7 V.

[0050] 7, the step-down DC / DC converter 12 converts a voltage of 5.7 V to a voltage of 1.2 V. In the setting example shown in FIG. 7, the LDO 13 converts a voltage of 5.7 V to a voltage of 5.0 V.

[0051] 7, the LDO 14 converts a voltage of 5.7 V to a voltage of 3.3 V. In the setting example shown in FIG. 7, the tracker 15 converts a voltage of 5.7 V to a voltage of 5.0 V.

[0052] The setting example shown in FIG. 7 is suitable when the load on the LDO 14 is small, that is, when the output current of the LDO 14 is small.

[0053] In the setting example shown in FIG. 7, the step-down DC / DC converter 11 receives the output voltage of the step-up DC / DC converter 18, so there is no need to take measures against a temporary drop in the input voltage VIN due to, for example, vehicle cranking.

[0054] 8 is a diagram showing a fourth example of use of the power management circuit 1. The fourth example of use differs from the first example of use in that voltage VOUT1 is applied to terminals T9 and T11 instead of voltage VOUT6, but is otherwise the same as the first example of use.

[0055] Fig. 9 is a schematic diagram for explaining a setting example in the fourth use example, in which external components and the like are omitted from the illustration.

[0056] In the setting example shown in FIG. 9, the step-down DC / DC converter 11 converts the input voltage VIN to a voltage of 3.8V.

[0057] 9, the step-down DC / DC converter 12 converts a voltage of 3.8 V to a voltage of 1.2 V. In the setting example shown in FIG. 9, the LDO 13 converts a voltage of 3.8 V to a voltage of 3.3 V.

[0058] 9, the LDO 14 converts a voltage of 3.8 V to a voltage of 3.3 V. In the setting example shown in FIG. 9, the tracker 15 converts a voltage of 3.8 V to a voltage of 3.3 V.

[0059] In the setting example shown in FIG. 9, the step-up DC / DC converter 18 converts a voltage of 3.8V to a voltage of 5.0V.

[0060] The example setup shown in FIG. 9 is suitable when both high and low output voltages are required.

[0061] In the setting example shown in FIG. 9, the output voltage of the step-down DC / DC converter 11 is low, so there is no need to take measures against a temporary drop in the input voltage VIN due to, for example, cranking of the vehicle.

[0062] <Application Example> The above-described power management circuit 1 is mounted on, for example, an electronic control unit (ECU) 4 shown in Fig. 10. In addition to the power management circuit 1, the electronic control unit 4 shown in Fig. 10 has a microcontroller unit (MCU) 2 and an input / output interface 3.

[0063] The microcontroller unit 2 uses the multiple voltages output from the power management circuit 1 as power supply voltages. The input / output interface 3 inputs external conditions and outputs drive signals to external devices. For example, if the electronic control unit 4 is an electronic control unit for a lamp, the input / output interface 3 inputs the condition of a lamp switch, and the microcontroller unit outputs a drive signal generated in accordance with the condition of the lamp switch.

[0064] The vehicle 5 shown in FIG. 11 has the electronic control unit 4 shown in FIG.

[0065] <Others> In addition to the above-described embodiments, various modifications can be made to the configuration of the invention without departing from the spirit of the invention. The above-described embodiments are illustrative in all respects and should be considered not to be limiting. The technical scope of the present invention is defined by the claims, not by the description of the above-described embodiments, and should be understood to include all modifications that fall within the meaning and scope of the claims.

[0066] The power management circuit (1) described above has a configuration (first configuration) including a first terminal (T1), a second terminal (T7), a third terminal (T9), a first step-down DC / DC converter (11) configured to receive a first voltage applied to the first terminal, a first linear regulator (13) configured to receive a second voltage applied to the second terminal, a second linear regulator (14) configured to receive a third voltage applied to the third terminal, and a step-up DC / DC converter control circuit (16) configured to receive the output voltage of the first step-down DC / DC converter.

[0067] The power management circuit of the first configuration described above can reduce losses in both the first linear regulator and the second linear regulator by utilizing the output voltages of the first step-down DC / DC converter and the step-up DC / DC converter, even if the output voltages of the first linear regulator and the second linear regulator are significantly different from each other.

[0068] In the power management circuit of the first configuration described above, the second voltage may be the output voltage of the first step-down DC / DC converter, and the third voltage may be the output voltage of the step-up DC / DC converter (second configuration).

[0069] The power management circuit of the second configuration described above can appropriately utilize the output voltages of the first step-down DC / DC converter and the step-up DC / DC converter when the output voltages of the first linear regulator and the second linear regulator are significantly different from each other.

[0070] In the power management circuit of the second configuration, the output voltage of the second linear regulator may be higher than the output voltage of the first step-down DC / DC converter (third configuration).

[0071] The power management circuit of the third configuration described above can appropriately utilize the output voltages of the first step-down DC / DC converter and the step-up DC / DC converter when the output voltages of the first linear regulator and the second linear regulator are significantly different from each other.

[0072] The power management circuit of any of the first to third configurations may have a configuration (fourth configuration) including a second step-down DC / DC converter (12) configured to receive the second voltage, and a power supply circuit (15) configured to receive the third voltage and supply power to the sensor.

[0073] The power management circuit of the fourth configuration has a second step-down DC / DC converter and a power supply circuit, and therefore has a wider range of applications than a configuration that does not have a second step-down DC / DC converter and a power supply circuit.

[0074] The power management circuit of any of the first to fourth configurations may be configured to be mounted on a one-chip semiconductor integrated circuit device (fifth configuration).

[0075] The power management circuit of the fifth configuration described above is capable of suppressing heat generation even though it has a configuration in which both the primary power supply and the secondary power supply are built into a single-chip semiconductor integrated circuit device.

[0076] The electronic control unit (4) described above may have a configuration (sixth configuration) including a power management circuit of any one of the first to fifth configurations and a microcontroller unit (2) configured to be supplied with power from the power management circuit.

[0077] The electronic control unit of the sixth configuration can reduce the loss in the power management circuit.

[0078] The vehicle (5) described above has a configuration (seventh configuration) including the electronic control unit of the sixth configuration.

[0079] The vehicle having the seventh configuration can reduce loss in the power management circuit.

[0080] REFERENCE SIGNS LIST 1 Power management circuit 2 MCU 3 Input / output interface 4 ECU 5 Vehicle 11, 12 Step-down DC / DC converter 13, 14 LDO 15 Tracker 16 Control circuit of step-up DC / DC converter 17 Communication unit 18 Step-up DC / DC converter C1 to C5 Capacitor D1 Diode L1 to L3 Inductor Q1 N-channel MOS field effect transistor R1 Current sense resistor T1 to T20 Terminal

Claims

1. A first terminal; A second terminal; A third terminal; a first step-down DC / DC converter configured to receive a first voltage applied to the first terminal; a first linear regulator configured to receive a second voltage applied to the second terminal; a second linear regulator configured to receive a third voltage applied to the third terminal; a step-up DC / DC converter control circuit configured to receive an output voltage of the first step-down DC / DC converter; A power management circuit having:

2. the second voltage is an output voltage of the first step-down DC / DC converter, 2. The power management circuit according to claim 1, wherein the third voltage is an output voltage of the step-up DC / DC converter.

3. 3. The power management circuit according to claim 2, wherein the output voltage of the second linear regulator is greater than the output voltage of the first step-down DC / DC converter.

4. a second step-down DC / DC converter configured to receive the second voltage; a power supply circuit configured to receive the third voltage and power the sensor; 2. The power management circuit of claim 1, comprising:

5. 2. The power management circuit according to claim 1, which is mounted on a one-chip semiconductor integrated circuit device.

6. A power management circuit according to any one of claims 1 to 5; a microcontroller unit configured to be powered by the power management circuit; An electronic control unit having

7. A vehicle comprising an electronic control unit according to claim 6.