Power management module

Abstract

The utility model discloses a power management module, which comprises a power management chip, a bootstrap unit and an anti-reverse unit, a voltage reduction unit is arranged in the power management chip; the bootstrap unit comprises a first switch tube; the anti-reverse unit comprises a second switch tube, a first diode, a third switch tube and a first resistor; the power supply input end is connected with the first end of the second switch tube, the second end of the second switch tube is connected with the second end of the first switch tube, and the control end of the second switch tube is connected with the control end of the first switch tube; the first end of the third switch tube is connected with the control end of the second switch tube, and the control end of the third switch tube is grounded through the first resistor; the positive electrode and the negative electrode of the first diode are respectively connected with the first end of the second switch tube and the second end of the third switch tube; and the second end of the first switching tube is also connected with the power supply end of the voltage reduction unit.

Description

Technical Field

[0001] The embodiment of the utility model relates to electronic circuit technology, and in particular to a power management module. Background Art

[0002] As is known in the automotive field, more and more controllers use PMIC (Power Management IC), but the electrical environment of these PMIC applications is a 12V power supply environment. If the controller is to be used in a 24V and 48V power supply system, a DCDC circuit needs to be added in the front stage of the PMIC.

[0003] At present, the application of low-voltage PMIC in high-voltage electrical environment requires the setting of complex step-down circuits, and lacks protection functions such as overvoltage and reverse connection. There is an urgent need for a PMIC for a 12V power supply system with step-down and overvoltage protection functions so that the PMIC of the 12V power supply system can be used normally in a 24V system. Utility Model Content

[0004] The utility model provides a power management module, so as to achieve the purpose of enabling a low-voltage power management chip to be applied in a high-voltage environment with certain safety.

[0005] The embodiment of the utility model provides a power management module, including: a power management chip, a bootstrap unit, and an anti-reverse unit;

[0006] The power management chip includes a voltage reduction unit inside;

[0007] The bootstrap unit comprises a first switch tube;

[0008] The anti-reverse unit includes a second switch tube, a first diode, a third switch tube and a first resistor;

[0009] The power input end is connected to the first end of the second switch tube, the second end of the second switch tube is connected to the second end of the first switch tube, and the control end of the second switch tube is connected to the control end of the first switch tube;

[0010] The first end of the third switch tube is connected to the control end of the second switch tube, and the control end of the third switch tube is grounded through the first resistor;

[0011] The positive electrode and the negative electrode of the first diode are connected to the first end of the second switch tube and the second end of the third switch tube respectively;

[0012] The second end of the first switch tube is also connected to the power supply end of the step-down unit, and the first switch tube is also used to be turned on or off according to the bootstrap voltage of the bootstrap unit;

[0013] When the first switch tube is turned on, the voltage drop between the input voltage of the power input terminal and the output voltage of the step-down unit reaches a minimum value.

[0014] Optionally, a protection unit is further included, wherein the protection unit includes a first clamping diode and a second diode;

[0015] The anode of the first clamping diode is connected to the control end of the second switch tube, the cathode of the first clamping diode is connected to the anode of the second diode, and the cathode of the second diode is grounded.

[0016] Optionally, the bootstrap unit includes a first capacitor, a third diode, a second capacitor and a second resistor;

[0017] The voltage output end of the step-down unit is connected to the first end of the third diode through the first capacitor, and the second end of the third diode is connected to the control end of the first switch tube through the second resistor;

[0018] The first end and the second end of the second capacitor are connected to the second end and the ground end of the third diode respectively.

[0019] Optionally, it further includes a voltage limiting unit, wherein the voltage limiting unit includes a second clamping diode and a fourth diode;

[0020] The first end of the second clamping diode is connected to the control end of the first switch tube, and the second end of the second clamping diode is connected to the power supply end of the buck unit through the fourth diode.

[0021] Optionally, it further includes a boost unit, wherein the boost unit includes a first inductor, a third capacitor, a third switch tube, a fifth diode, and a third resistor;

[0022] The second end of the first switch tube is connected to the anode of the fifth diode through the first inductor, and the cathode of the fifth diode is connected to the power supply end of the step-down unit;

[0023] The first end of the third switch tube is connected to the anode of the fifth diode, and the second end of the third switch tube is grounded through the third resistor;

[0024] The control end of the third switch tube is connected to the control end of the power management chip;

[0025] The first end and the second end of the third capacitor are connected to the cathode of the fifth diode and the ground terminal respectively.

[0026] Optionally, the third switching tube is a triode.

[0027] Optionally, the first switch tube and the second switch tube are NMOS tubes, and the gate-source threshold voltage of the first switch tube and the second switch tube is 2-4V.

[0028] Optionally, the output voltage of the power management chip is 12V.

[0029] Optionally, the fourth switch tube is an NMOS tube.

[0030] Optionally, the input voltage of the power input terminal is 4.5~60V.

[0031] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention proposes a power management module, which includes a power management chip U1, a bootstrap unit, and an anti-reverse unit; the power management chip contains a step-down unit; the bootstrap unit includes a first switch tube Q2; the anti-reverse unit includes a second switch tube Q1, a first diode D3, a third switch tube Q3 and a first resistor R2; wherein, based on the first switch tube Q2 and the second switch tube Q1, when the input voltage of the power management chip exceeds a certain value, the step-down unit can be operated, so that the low-voltage power management chip can be applied to a high-voltage electrical environment, avoiding the need to add a DCDC circuit in the front stage of the power management chip to increase the complexity of the module when achieving the same effect. In addition, based on the second switch tube Q1, anti-reverse protection for the power management chip can also be achieved, thereby improving the safety of the power management chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is a schematic diagram of the structure of a power management module in an embodiment;

[0033] Figure 2 It is a schematic diagram of another power management module structure in the embodiment. DETAILED DESCRIPTION

[0034] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only the parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0035] Figure 1 is a schematic diagram of the power management module structure in the embodiment, refer to Figure 1 ,The power management module includes: power management chip U1, bootstrap unit, anti-reverse unit;

[0036] The power management chip contains a step-down unit;

[0037] The bootstrap unit includes a first switch tube Q2;

[0038] The anti-reverse unit includes a second switch tube Q1, a first diode D3, a third switch tube Q3 and a first resistor R2;

[0039] The power input terminal Input is connected to the first terminal of the second switch tube Q1, the second terminal of the second switch tube Q1 is connected to the second terminal of the first switch tube Q2, and the control terminal of the second switch tube Q1 is connected to the control terminal of the first switch tube Q2;

[0040] A first end of the third switch tube Q3 is connected to the control end of the second switch tube Q1, and the control end of the third switch tube Q3 is grounded through the first resistor R2;

[0041] The anode and cathode of the first diode D3 are connected to the first end of the second switch tube Q1 and the second end of the third switch tube Q3 respectively;

[0042] The second end of the first switch tube Q2 is also connected to the power supply end of the step-down unit, and the first switch tube Q2 is also used to turn on or off according to the bootstrap voltage of the bootstrap unit;

[0043] When the first switch tube Q2 is turned on, the voltage drop between the input voltage of the power input terminal and the output voltage of the step-down unit reaches a minimum value.

[0044] For example, in this embodiment, the model of the power management chip (Power Management IC, PMIC) U1 is not specifically limited and can be freely selected according to demand. Accordingly, the structure of the buck unit configured inside it is not described in detail, which is related to the model of the selected power management chip.

[0045] In this embodiment, the power supply (input) end and the output end of the step-down unit are set to be designated pins of the power management chip U1 respectively, the power supply end of the step-down unit is set to be connected to the second end of the first switch tube Q2, and the output end of the step-down unit is connected to the (input end) of the bootstrap unit.

[0046] Exemplarily, in this solution, the third switch tube Q3 may be a triode.

[0047] Exemplarily, in this embodiment, the working principles of the power management chip U1 (step-down unit), the bootstrap unit, and the anti-reverse unit are as follows:

[0048] When the power input terminal Input is connected to a power supply lower than a specified voltage threshold, the parasitic diode of the second switch tube Q1 is forward-conducted, and the D-pole of Q1 outputs a voltage lower than the power supply by Vsd (Diode forward voltage) to the D-pole of the first switch tube Q2;

[0049] At this time, the buck unit (BUCK circuit) has not started working yet, the G-pole voltages of Q1 and Q2 are at a floating level, and the S-pole of Q2 can output a level of Vd-Vgson until the buck unit starts working, where Vgson is the gate-source threshold voltage of Q2;

[0050] For the buck unit to start working, the power supply voltage (VIN) at the power input terminal Input must be higher than the output voltage +Vgson+Vsd of the buck unit, so that the buck unit can be started and output a normal voltage;

[0051] When the buck unit starts to work, the bootstrap unit gradually increases the output voltage of the buck unit to a specified value;

[0052] When the bootstrap unit raises the voltage at the control end of the first switch tube Q2 to VIN+Vgson, Q1 and Q2 are turned on, and the voltage drop from the power input end Input to the buck unit is reduced to the minimum;

[0053] When the power input is reversed and a negative voltage is input, the VIN voltage is lower than the GND terminal, and the current on the first resistor R2 is amplified by the third switch tube Q3, so that the Vgs of the second switch tube Q1 is clamped to about 0.7V. At this time, the second switch tube Q1 is turned off to realize the negative voltage protection function for the subsequent circuit.

[0054] For example, in this embodiment, other circuit components of the bootstrap unit except the first switch tube Q2 are not limited. Figure 1 In addition to the first switch tube Q2, the bootstrap unit may also include:

[0055] The bootstrap unit includes a first capacitor C4, a third diode D2, a second capacitor C1 and a second resistor R1;

[0056] The voltage output end of the step-down unit is connected to the first end of the third diode D2 through the first capacitor C4, and the second end of the third diode D2 is connected to the control end of the first switch tube Q2 through the second resistor R1;

[0057] A first end and a second end of the second capacitor C1 are connected to the second end and a ground end of the third diode D2 respectively.

[0058] In this scheme, the bootstrap unit works as follows:

[0059] When the BUCK circuit in the step-down unit starts to work, the first capacitor C4 starts to charge and discharge, and based on the output voltage of the BUCK circuit, the voltage of the second capacitor C1 is gradually increased to a specified value;

[0060] When the voltage of the second capacitor C1 is increased to VIN+Vgson, Q1 and Q2 are turned on, and the voltage drop from VIN to the output voltage of the BUCK circuit is reduced to the minimum.

[0061] For example, in this solution, before Q1 is turned on, its diode characteristic has a PN junction voltage drop, and the gate level of Q2 is a floating voltage with a voltage drop of about Vgson. After Q1 and Q2 are turned on, these voltage drops disappear, so the voltage drop from VIN to the output voltage of the BUCK circuit can be minimized.

[0062] The present embodiment proposes a power management module, which includes a power management chip U1, a bootstrap unit, and an anti-reverse unit; the power management chip includes a step-down unit; the bootstrap unit includes a first switch tube Q2; the anti-reverse unit includes a second switch tube Q1, a first diode D3, a third switch tube Q3 and a first resistor R2; wherein, based on the first switch tube Q2 and the second switch tube Q1, when the input voltage of the power management chip exceeds a certain value, the step-down unit can be operated, so that the low-voltage (for example, 12V) power management chip can be applied to a high-voltage electrical environment (for example, 24~48V), avoiding the problem of adding a DCDC circuit in the front stage of the power management chip to increase the complexity of the module when achieving the same effect. In addition, based on the second switch tube Q1, anti-reverse protection for the power management chip can also be achieved, thereby improving the safety of the power management chip.

[0063] Figure 2 is another schematic diagram of the structure of the power management module in the embodiment, refer to Figure 2 ,exist Figure 1 Based on the scheme shown, in one possible implementation scheme, the power management module further includes a protection unit, and the protection unit includes a first clamping diode Z2 and a second diode D5;

[0064] The anode of the first clamping diode Z2 is connected to the control end of the second switch tube Q1 , the cathode of the first clamping diode Z2 is connected to the anode of the second diode D5 , and the cathode of the second diode D5 is grounded.

[0065] Exemplarily, in this solution, when the voltage at the control end of the first switch tube Q2 is higher than VIN+Vgs, the first clamping diode Z2 reversely breaks down to clamp the Vgs voltage of the first switch tube Q2 to protect Q2.

[0066] refer to Figure 2 ,exist Figure 1 On the basis of the scheme shown, in one possible implementation scheme, the power management module further includes a voltage limiting unit, and the voltage limiting unit includes a second clamping diode Z1 and a fourth diode D1;

[0067] A first end of the second clamping diode Z1 is connected to the control end of the first switch tube Q2 , and a second end of the second clamping diode Z1 is connected to the power supply end of the step-down unit through the fourth diode D1 .

[0068] In this solution, the purpose of setting the second clamping diode Z1 is that when the input voltage of the power input terminal Input is higher than the clamping voltage -Vgson of Z1, the output voltage of the first switch tube Q2 is limited to VZnom-Vgson, where Vznom is the nominal voltage regulation value of the second clamping diode Z1.

[0069] Exemplarily, in this solution, the second clamping diode Z1 and the first switch tube Q2 may be selected as follows:

[0070] If the withstand voltage level of the power management chip U1 is 12V, an 18V Zener diode can be selected as the second clamping diode, and an N-MOS with a Vgson of 2V can be selected as the first switch tube, which can protect the output voltage (of the first switch tube) below 16V;

[0071] If the withstand voltage level of the power management chip U1 is 24V, a 36V Zener diode can be selected as the second clamping diode, and an N-MOS with a Vgson of 2V can be selected as the first switch tube, which can protect the output voltage (of the first switch tube) at around 34V.

[0072] refer to Figure 2 ,exist Figure 1 On the basis of the scheme shown, in one possible implementation scheme, the power management module further includes a boost unit, which includes a first inductor L1, a third capacitor C3, a fourth switch tube Q4, a fifth diode D4, and a third resistor D4;

[0073] The second end of the first switch tube Q2 is connected to the anode of the fifth diode D4 through the first inductor L1, and the cathode of the fifth diode D4 is connected to the power supply end of the step-down unit;

[0074] A first end of the fourth switch tube Q4 is connected to the anode of the fifth diode D4, and a second end of the fourth switch tube Q4 is grounded via a third resistor R3;

[0075] The control end of the fourth switch tube Q4 is connected to the control end of the power management chip U1;

[0076] A first end and a second end of the third capacitor C3 are connected to the cathode of the fifth diode D4 and the ground terminal respectively.

[0077] In this solution, the first inductor L1, the fourth switch tube Q4, the fifth diode D4 and the third capacitor C3 constitute a typical boost circuit, and its specific working principle will not be described in detail;

[0078] The third resistor R3 is used as a current detection resistor, and the power management chip U1 can determine the output current of the fourth switch tube Q4 by detecting the voltage across the third resistor R3;

[0079] When the current is too large, the power management chip U1 can be configured to actively disconnect the fourth switch tube Q4 to avoid damage to the fourth switch tube Q4.

[0080] Exemplarily, in this solution, the fourth switch tube may be an NMOS tube.

[0081] In this solution, the boost unit is configured to adjust the output voltage of the first switch tube Q2 to ensure the stability of the voltage output to the buck unit.

[0082] exist Figure 1 On the basis of the scheme shown, in one possible implementation scheme, the first switch tube Q2 and the second switch tube Q1 are NMOS tubes, and the gate-source threshold voltage of the first switch tube Q2 and the second switch tube Q1 is 2-4V.

[0083] Among them, Q1 and Q2 use N-MOSFET models with lower Vgson (2-4V) and high enough withstand voltage (able to withstand high voltage), and the heat dissipation power of Q2 should be large enough;

[0084] The purpose of this selection method is that during overvoltage, the Vds voltage drop of Q2 is large, and Q2 must bear its own power loss to achieve the purpose of protecting the subsequent step-down unit.

[0085] exist Figure 1 Based on the scheme shown, in one possible implementation scheme, the output voltage of the power management chip is set to 12V.

[0086] exist Figure 1 Based on the scheme shown, in one possible implementation scheme, the input voltage of the power input terminal is 4.5-60V.

[0087] refer to Figure 2 , the schemes of any of the aforementioned power management modules can be freely combined, and their corresponding devices, connection methods and working principles are the same as those of the aforementioned corresponding schemes, which will not be described in detail here;

[0088] In addition, based on the selection of the power management chip U1, the required peripheral devices can also be configured as needed. For example, the inductor L2, the capacitor C7 and the buck unit in the power management chip U1 constitute a buck circuit; the capacitor C2 serves as a reset capacitor of the power management chip U1.

[0089] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention is described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A power management module, characterized in that: include: Power management chip, bootstrap unit, anti-reverse unit; The power management chip includes a voltage reduction unit inside; The bootstrap unit comprises a first switch tube; The anti-reverse unit includes a second switch tube, a first diode, a third switch tube and a first resistor; The power input end is connected to the first end of the second switch tube, the second end of the second switch tube is connected to the second end of the first switch tube, and the control end of the second switch tube is connected to the control end of the first switch tube; The first end of the third switch tube is connected to the control end of the second switch tube, and the control end of the third switch tube is grounded through the first resistor; The positive electrode and the negative electrode of the first diode are connected to the first end of the second switch tube and the second end of the third switch tube respectively; The second end of the first switch tube is also connected to the power supply end of the step-down unit, and the first switch tube is also used to be turned on or off according to the bootstrap voltage of the bootstrap unit; When the first switch tube is turned on, the voltage drop between the input voltage of the power input terminal and the output voltage of the step-down unit reaches a minimum value.

2. The power management module according to claim 1, characterized in that: Also includes a protection unit, the protection unit includes a first clamping diode and a second diode; The anode of the first clamping diode is connected to the control end of the second switch tube, the cathode of the first clamping diode is connected to the anode of the second diode, and the cathode of the second diode is grounded.

3. The power management module according to claim 1, characterized in that: The bootstrap unit includes a first capacitor, a third diode, a second capacitor and a second resistor; The voltage output end of the step-down unit is connected to the first end of the third diode through the first capacitor, and the second end of the third diode is connected to the control end of the first switch tube through the second resistor; The first end and the second end of the second capacitor are connected to the second end and the ground end of the third diode respectively.

4. The power management module according to claim 1, characterized in that: Also includes a voltage limiting unit, the voltage limiting unit includes a second clamping diode and a fourth diode; The first end of the second clamping diode is connected to the control end of the first switch tube, and the second end of the second clamping diode is connected to the power supply end of the buck unit through the fourth diode.

5. The power management module according to claim 1, wherein: It also includes a boost unit, which includes a first inductor, a third capacitor, a fourth switch tube, a fifth diode, and a third resistor; The second end of the first switch tube is connected to the anode of the fifth diode through the first inductor, and the cathode of the fifth diode is connected to the power supply end of the step-down unit; The first end of the third switch tube is connected to the anode of the fifth diode, and the second end of the third switch tube is grounded through the third resistor; The control end of the third switch tube is connected to the control end of the power management chip; The first end and the second end of the third capacitor are connected to the cathode of the fifth diode and the ground terminal respectively.

6. The power management module according to claim 1, wherein: The third switch tube is a triode.

7. The power management module according to claim 1, characterized in that: The first switch tube and the second switch tube are NMOS tubes, and the gate-source threshold voltage of the first switch tube and the second switch tube is 2-4V.

8. The power management module according to claim 1, wherein: The output voltage of the power management chip is 12V.

9. The power management module according to claim 5, characterized in that: The fourth switch tube is an NMOS tube.

10. The power management module according to claim 1, characterized in that: The input voltage of the power input terminal is 4.5~60V.

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