JP3469715B2 - High-speed response low-loss regulator - Google Patents

Description

Description: BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a constant voltage power supply circuit (regulator) for a fast change in load current.
In particular, it relates to a high-speed response low-loss regulator. 2. Description of the Related Art FIG. 10 shows a circuit diagram of a conventional low-loss regulator. The conventional low-loss regulator 50 is PN
It is composed of a P output transistor 51, a control circuit 52, and feedback control split resistors R1 (53) and R2 (54). The current from the power supply circuit is supplied to the input terminal 55 (G
ND side), 56 (Vin). On the output side, a load is connected to output terminals 57 (GND side) and 58 (Vout). The conventional low-loss regulator feeds back a change in the output voltage Vout to a control circuit via a feedback resistor, controls the base current of the PNP output transistor 51 according to the amount of feedback, and controls the output voltage in response to a change in the output current. , And stable power was supplied to the load as a constant voltage power supply. In order to stabilize the output of a power supply circuit, an electrolytic capacitor is often used on the output side of a low-loss regulator.
JP-B-3-76573 and JP-A-7-263276
The former relates to a solid electrolytic capacitor using a TCNQ complex salt as an electrolyte, and the latter relates to a method for removing noise of electronic equipment. [0004] However, the conventional low-loss regulator has the following problems. With the advent of the multimedia era, personal computers have become widespread, and speeding up and power savings are desired. The clock frequency of the CPU of the conventional personal computer was 20 to 30 MHz, but recently the speed has been rapidly increased to 100 to 160 MHz and more, and the required output current is also 1 amp (A). From about 2 amps (A) to 4 A to 10 A or more, a high-speed, large-current regulator is desired. The present invention has been made in view of the above problems. [0005] High-speed response low dropout regulator of the present invention In order to achieve the above object, according, PNP output transistor and divide the output voltage of the control circuit and the PNP output transistor that controls the base current of said PNP output transistor A feedback split resistor for feeding back to the control circuit, wherein the high-speed response low-loss regulator controls the base current of the PNP output transistor in accordance with the amount of feedback from the feedback split resistor. And between the base
A base current adjusting resistor for increasing the base current of the PNP output transistor and shortening the recovery time of the voltage response is connected, and the ground potential of the IC chip including the control circuit is adjusted .
The fast response and low loss between the bottom and the frame of output potential
Capacitor connected in parallel with the output terminal
Mounting the IC chip and the organic semiconductor solid electrolyte
The capacitor and the output of the high-speed response low-loss regulator
It is characterized by being connected in parallel between the terminal and the GND terminal . An embodiment of the present invention will be described below in detail with reference to the accompanying drawings. I do. [0015] [Reference Example 1] The fast response low dropout regulator of Reference Example 1 of the present invention shown in FIG. 1, which is of a type to be passed to advance base current. The first high-speed response low-loss regulator main body 1 includes a PNP output transistor 2, a control circuit 3, feedback-control split resistors R1 (4) and R2 (5), and a base current adjusting resistor Rb (6). The current from the power supply circuit 12 is supplied to the input terminal 7
(GND side), 8 (Vin). On the output side, external large-capacity capacitors 14 and 15 and a load 16 are connected to output terminals 10 (GND side) and 11 (Vout). The feedback voltage Vref from the feedback control dividing resistors R1 (4) and R2 (5) is
Is added to the control circuit 3. Further, as shown in the figure, external large-capacity capacitors 14 and 15 are connected in parallel. 13 is a GND (earth) terminal. As will be described in detail with reference to FIG. 9, the PNP output transistor 2, the control circuit 3, the feedback control split resistors R1 (4) and R2 (5), and the base current adjusting resistor Rb (6) are combined into one frame. When mounted on top and feedback control split resistors R1 (4) and R2 (5)
Is not implemented on one frame. FIG. 2 shows external large-capacity capacitors 14, 1
5, a normal 680 μF aluminum electrolytic capacitor and a 100 μF high-speed response capacitor (organic semiconductor solid electrolytic capacitor) are connected in parallel, and the input voltage Vin =
5.0 V, output voltage Vout = 3.3 V, output current 4 A
The response characteristics (upper row) and the output current response properties (lower row) of the output voltage fluctuation corresponding to the load fluctuation in the case of (1) are shown. The lower diagram shows that the load fluctuation is 0 A (ampere)
The output voltage fluctuation is 200 mV with respect to a load fluctuation from 4 to 4 A (ampere). The upper part shows the response characteristics of the output voltage,
The horizontal axis is the time axis (unit: 10 μsec), and the vertical axis is the output terminal 1
The fluctuation of the voltage (unit: 200 mV) between 0 and 11 is shown.
The time required for this voltage waveform to reach a peak is about 0.3 to
It is about 1.0 μsec, and the peak voltage Vp at this time is about 200 mV. In FIG. 2, the time until the voltage fluctuation starts to show a recovery tendency by the function of the control circuit 3 is defined as a recovery time Td. In the case of FIG. 2, the recovery time Td = about 12 μsec. The effect of the high-speed response capacitor (organic semiconductor solid electrolytic capacitor) of the large-capacity capacitor 15 in FIG. 2 will be further described. As described in Japanese Patent Publication No. 3-76573, this organic semiconductor solid electrolytic capacitor uses a TCNQ complex salt as an electrolyte, and has an equivalent series resistance E in a high frequency region of 100 kHz or more.
-SR is extremely small, 70 to 600 mΩ or less. Therefore, the responsiveness of the high-speed responsive low-loss regulator can be improved by using it in parallel with a normal aluminum electrolytic capacitor. The capacity Co of the organic semiconductor solid electrolytic capacitor and the capacity Ca of the ordinary aluminum electrolytic capacitor
Is that Co: Ca = 1: 2 to 10 is effective for the high-speed response of the high-speed response low-loss regulator,
It is effective that the capacitance Co of the organic semiconductor solid electrolytic capacitor is 30 μF or more. Equivalent series resistance ES
-Due to the magnitude of R, the capacity of a normal aluminum electrolytic capacitor is effective in a low frequency range, while the capacity of an organic semiconductor solid electrolytic capacitor works effectively in a high frequency range of 100 kHz or more. As a comparative example, when two ordinary aluminum electrolytic capacitors of 680 μF + 100 μF = 780 μF are connected in parallel as an external capacitor, the peak voltage Vp is about 400 mV, and the recovery time Td is about 3 μm.
It is about 0 μsec. These results also confirmed the effect of connecting the organic semiconductor solid electrolytic capacitor in parallel with a normal aluminum electrolytic capacitor. FIG. 3 shows a change in the peak voltage Vp when the base resistance Rb (6) in FIG. 1 is changed. The horizontal axis indicates the value of the base resistance Rb, and the vertical axis indicates the peak voltage Vp. It is a thing. FIG. 4 shows the base resistor Rb (6) of FIG.
Indicates the change in the recovery time Td of the fluctuating voltage with respect to the change, in which the abscissa indicates the value of the base resistance Rb and the ordinate indicates the recovery time Td. At this time, a 220 μF ordinary aluminum electrolytic capacitor and a 47 μF high-speed response capacitor (organic semiconductor solid electrolytic capacitor) are connected in parallel to the external large-capacitance capacitors 14 and 15 in FIG. 2, respectively, and the input voltage Vin = 3.3 V , Output voltage Vout =
This is the case where the output current changes from 0 A to 5 A at 2.5 V. In FIG. 3, the peak voltage Vp is 160 mV, 200 mV, 3 Ω for the values of the base resistance Rb (6) of 50Ω, 90Ω, 180Ω, 360Ω and 820Ω.
20 mV, 370 mV and 400 mV. In FIG. 4, when the value of the base resistor Rb (6) is 50Ω, 90Ω, 180Ω, 360Ω and 820Ω, the recovery time of the voltage response is 2 μsec and 4Ω, respectively.
μsec, 6 μsec, 8 μsec and 9 μsec. The value of the base resistor Rb (6) shown in FIG.
When replaced with the base current of the output transistor 2, the value of the base resistance Rb is 50Ω, 90Ω, 180Ω, 360Ω.
And 820Ω, the base current is 14.0
mA, 7.8 mA, 3.9 mA, 1.9 mA and 0.8
5 mA. In other words, the longer the base current, the shorter the voltage response recovery time. When the base resistance Rb is equal to or more than 820 Ω, the base current (0.85 mA in this case) hardly flows, which is close to the conventional technology. From the viewpoint of an allowable peak voltage and power consumption, the effect of high-speed response is remarkable when the base current is 5 mA or more. In order to respond to a high-speed, large-current load change such as a CPU drive of a personal computer at a high speed, a base current of a PNP transistor used in an output stage is supplied in advance to be used in an output stage. P
A function of responding to a change in load at a high speed without saturating the NP transistor, that is, without using the NP transistor completely ON and OFF, is provided. At this time, the recovery time of the voltage response is 12 μs
c to 10 μsec, which corresponds to about 100 MHz when viewed from the clock frequency of the CPU of the personal computer. According to the present invention shown in FIG. 1, a high-speed, large-current regulator with a clock frequency of 100 MHz to 160 MHz or more of the CPU of the personal computer and an output current of about 4 A to 10 A or more can be realized. [Embodiment 2 ] Embodiment 2 of the present invention shown in FIG. 5 is a system in which a capacitor is connected to the PNP output transistor 2. This second high-speed response low-loss regulator main body 17 includes a PNP transistor 2 in the output stage. A capacitor 18 is added to the collector and the emitter of the regulator to reduce the output voltage of the regulator when the load changes at a high speed. The second high-speed response low-loss regulator body 17
Is composed of a PNP output transistor 2, a control circuit 3, and feedback control division resistors R1 (4) and R2 (5). The current from the power supply circuit 12 is supplied to the input terminal 7
(GND side), 8 (Vin). The outputs are terminals 10 (GND side) and 11 (Vout), and the load 16
Also, external large-capacity capacitors 14 and 15 are connected. The capacitance of the capacitor 18 connected in parallel to the PNP output transistor 2 is about 1 μF or less, and the peak voltage Vp is 200 m
V or less, the recovery time Td can be suppressed to about 15 μsec, and a high-speed response low-loss regulator can be realized. Also, from the point of high-speed response, PN
An organic semiconductor solid electrolytic capacitor can be used as the capacitor 18 connected in parallel with the P output transistor 2. [0030] [Reference Example 3 Reference Example 3 of the present invention shown in FIG. 6 is a method for connecting a parallel capacitor to the feedback control for dividing resistor R1,
The third high-speed response low-loss regulator main body 19 is a feedback control split resistor for monitoring the output voltage and feeding back to the amplifier of the regulator in order to quickly respond to a change in load. A parallel capacitor 20 is connected to the resistor R1 (4) added to the feedback voltage Vref of R1 (4) and R2 (5) to provide a function of responding quickly to a change in load. Referring to FIG. 6, the third high-speed response low-loss regulator main body 19 includes a PNP output transistor 2, a control circuit 3, and a feedback control dividing resistor R1.
(4) and R2 (5), and a parallel capacitor 20. The current from the power supply circuit 12 is supplied to the input terminal 7 (GN
D side), 8 (Vin). Output is terminal 10
(GND side), 11 (Vout), to which a load 16 and external large-capacity capacitors 14, 15 are connected. The capacitance of the capacitor 20 connected in parallel to the dividing resistor R1 is about 1 μF to 10 μF. This capacitor 20
Is a capacitor in a feedback portion, and has an effect of improving the frequency characteristics of the regulator amplifier (control circuit). On the other hand, capacitors 14 and 15 connected to the output terminal
Does not have such a function. Further, when the capacitance of the capacitor 20 connected in parallel to the dividing resistor R1 becomes about 10 μF or more, there is a possibility that the regulator amplifier (control circuit) may oscillate. [0032] Reference Example 4 Reference Example 4 of the present invention shown in FIG. 7 is a scheme in which additional output transistor, the fourth speed response low dropout regulator body 21, in order to respond quickly to changes in load To
An emitter and a collector of another additional PNP transistor 24 are connected between 22-23 between the base and the collector of the PNP transistor 2 used in the output stage,
A capacitor 25 is connected in series to the base of the NP transistor 24, and the other end of the capacitor 25 is connected to the feedback terminal Vref (9) of the control circuit 3 to have a function of responding quickly to a change in load. Referring to FIG. 7, the fourth high-speed response low-loss regulator body 21 includes a PNP output transistor 2, a control circuit 3, and a feedback control division resistor R1.
(4) and R2 (5), an additional PNP transistor 24 and a capacitor 25. The current from the power supply circuit 12 is supplied to the input terminals 7 (GND side) and 8 (Vi
n). Output is terminal 10 (GND side), 11
(Vout), and the load 16 and the external large-capacity capacitors 14 and 15 are connected. When the operation of the added PNP transistor 24 is viewed at a high frequency, the capacitor 25 is considered to be in a short-circuited state, and when the value of the feedback voltage Vref decreases, the transistor 24 operates and the output transistor 2
It acts to remove the base current. Therefore, Vref
If the output voltage drops, the output transistor 2
To increase the current flow and compensate for the decrease in output.
The capacity of the added capacitor 25 is about 1 μF to 10 μF. [0035] Reference Example 5 of the present invention shown in Reference Example 5 FIG. 8 is a scheme of the power supply from another power supply, high-speed response low dropout regulator body 26 in the fifth, the fast changes in load In order to respond, the power supply circuit of the PNP transistor 2 used in the output stage and the power supply circuit of the control circuit 3 are separated. In the power supply circuit shown in FIG. 1, the output voltage changes due to a load change, and the change is transmitted to the power supply circuit 12 of the control circuit 3, resulting in affecting the response characteristics of the control circuit 3. When the power supply voltage of the control circuit 3 decreases, the responsiveness of the control circuit decreases. More specifically, although it depends on the capacity of the power supply circuit 12, if the ideal power supply circuit, that is, the capacity is infinite, the power supply circuit is set to 1
It is not necessary to prepare two of 2 and 27. However, in reality, the capacity of the power supply circuit is finite, and the input voltage fluctuates under the influence of the fluctuation of the load 16. In this case, by separating the power supply circuit 12 used for the load and the power supply circuit 27 of the control circuit 3 of the regulator amplifier, it is possible to prevent the fluctuation of the load 16 from affecting the control circuit 3 of the regulator amplifier. . As described above, by separating the power supply circuit of the present invention, a function of responding to a change in load at high speed can be provided. Referring to FIG. 8, a fifth high-speed response low-loss regulator main body 26 includes a power supply circuit 27 for the control circuit 3 and a connection terminal 28 thereof.
It comprises an output transistor 2, a control circuit 3, and feedback control split resistors R1 (4) and R2 (5). The current from the power supply circuit 12 (see FIG. 1) for the PNP output transistor 2 is supplied to the input terminals 7 (GND side) and 8 (V
in). Output is terminal 10 (GND side), 1
1 (Vout), and the load 16 and the external large-capacity capacitors 14 and 15 are connected. [0037] [Embodiment 1] first the fast response low dropout regulator 1 of Reference Example 1 of the present invention shown in FIG. 1, the large-capacitance capacitor 14, 15 and the load 16 of the outer pickled output side output terminal 10 (GND
Side) and 11 (Vout). In the embodiment of the present invention shown in FIG. 9, a part of the external capacitor is mounted on the regulator body. In the sixth high-speed response low-loss regulator 29, a part of the external capacitor is mounted as the capacitor 30 of the regulator body. The capacitance is about several μF or less. FIG. 9A is a circuit diagram of a high-speed response low-loss regulator, FIG. 9B is a mounting drawing of the high-speed response low-loss regulator, and FIG. 9C is a mounting of the high-speed response low-loss regulator. FIG. 2 is a schematic sectional view of a capacitor 30. Referring to FIG. 9A, the sixth high-speed response low-loss regulator main body 29 includes a PNP output transistor 2, a control circuit 3, feedback-controlled split resistors R1 (4) and R2 (5), and a base current adjustment. It comprises a resistor Rb (6) and a mounting capacitor 30. The current from the power supply circuit 12 (see FIG. 1) is supplied to the input terminals 7 (GND side) and 8 (V
in). Split resistor R for feedback control
The voltage Vref (9) from 1 (4) and R2 (5) is applied to the control circuit 3. On the output side, external large-capacity capacitors 14, 15 and a load 16 are connected to an output terminal 10 (GND).
Side) and 11 (Vout), but the external large-capacity capacitors 14 and 15 and the load 16 are not shown (see FIG. 1). Referring to FIG. 9B, the control circuit 3 and the feedback control dividing resistor R
IC chip 31 including 1 (4) and R2 (5) and PNP
A transistor 32 on which the output transistor 2 is mounted is arranged. Under the IC chip 31, the insulating paste 3
4 attaches the mounting capacitor 30 to the frame 33. FIG. 9C is a schematic cross-sectional view of a mounting capacitor 30 of the high-speed response low-loss regulator.
Reference numeral 3 denotes a Vout (11) potential, which is mounted between the IC chip 31 and a GND (ground) potential at the bottom of the IC chip 31. The size of the frame 33 is approximately 15 mm × 1
5 mm, and the size of the IC chip 31 is
It is about 3 mm square. Therefore, the size of the mounting capacitor 30 allowed for mounting is approximately 10 mm × 10 mm, and the capacitance of the capacitor is 10 μF by die bonding between the IC chip 31 and the frame 33 using a high dielectric substance. It can be up to about several tens of μF. Also, instead of mounting a high dielectric substance between the IC chip 31 and the frame 33 constituting the regulator, a capacitor component is interposed and die-bonded, so that the output terminals Vout11 and Gout of the regulator are connected to each other.
A structure in which a capacitor component is added between the NDs 10 can be realized. As described as the external capacitor 14 in FIG. 1, a solid electrolytic capacitor component using an organic semiconductor (a surface-mounted solid electrolytic capacitor component is particularly optimal) can be mounted. In this case, the capacitance of the capacitor can be about 10 μF to several tens of μF. In the embodiment shown in FIG. 9, the same electrical effects as described with reference to FIGS. 1, 2 and 3 can be obtained in terms of circuit functions, and the mounting area can be reduced. In addition, it is particularly effective for the use of a high-speed response low-loss regulator that can be covered by the capacity of the mounting capacitor 30. In the example shown in FIG. 9, the PNP output transistor 2, the control circuit 3, and the feedback control dividing resistor R
1 (4) and R2 (5), base current adjusting resistor Rb
(6) is mounted on one frame, but there is also a variable type in which the feedback control division resistors R1 (4) and R2 (5) are not mounted on one frame. Further, it is needless to say that the base current adjusting resistor Rb (6) described in FIG. 1 of the present invention can be applied in combination with the invention shown in FIGS. 5, 6, 7 and 8. [0046] As is evident from the foregoing description, according to the high-speed response low dropout regulator of the present invention, a base connected to current regulation resistor between the emitter and base of the PNP output transistor,
By flowing the base current in advance, for example, 100
A high-current regulator with a high-speed response of not less than MHz and several A (ampere) or more can be realized, and the responsiveness of the PNP output transistor can be improved. In addition, it includes a control circuit
IC chip ground potential bottom and output potential frame
Between the output terminal of the high-speed response low-loss regulator
Mount organic semiconductor solid electrolytic capacitors connected in parallel.
The external organic semiconductor solid electrolytic capacitor
Is unnecessary, and the mounting area of the high-speed response low-loss regulator
Can be reduced. Also, this mounting capacitor
High speed response and low loss regulation that can be covered by about 30 capacity
It is particularly effective for data applications. [0047] [0048] [0049] [0050] [0051] Also, due to the value of the equivalent series resistance E · S · R for organic semiconductor solid electrolytic capacitor is small, 1
Voltage responsiveness of 00 kHz or more can be improved. [0053]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a circuit diagram of a high-speed response low-loss regulator according to Embodiment 1 of the present invention. FIG. 2 is a diagram showing response characteristics of a high-speed response low-loss regulator according to Embodiment 1 of the present invention, showing a response characteristic of an output voltage (upper part) and a response characteristic of an output current (lower part) corresponding to a load change; FIG. 3 shows a peak voltage Vp when the base resistance Rb of the high-speed response low-loss regulator according to the first embodiment of the present invention is changed.
FIG. FIG. 4 is a diagram illustrating a change in a recovery time Td when the base resistance Rb of the high-speed response low-loss regulator of the first embodiment of the present invention is changed. FIG. 5 is a circuit diagram of a high-speed response low-loss regulator according to a second embodiment of the present invention, in which a condenser is added to the collector and the emitter of the PNP transistor 2 in the output stage. FIG. 6 is a circuit diagram of a high-speed response low-loss regulator according to a third embodiment of the present invention;
FIG. 4 is a circuit diagram when a capacitor 20 is connected in parallel to (4). FIG. 7 is a circuit diagram of a high-speed response low-loss regulator according to Embodiment 4 of the present invention, in which another PNP transistor and a capacitor are connected to an output PNP transistor. FIG. 8 is a circuit diagram of a high-speed response low-loss regulator according to Embodiment 5 of the present invention, in which a power supply circuit of a PNP transistor for an output stage and a power supply circuit of a control circuit are separated. FIG. 9 is a diagram of a high-speed response low-loss regulator according to an embodiment of the present invention, (a) is a circuit diagram,
(B) is a mounting drawing, and (c) is a schematic sectional view of an IC chip, a capacitor, and a frame. FIG. 10 is a circuit diagram of a conventional low-loss regulator. [Description of Signs] 1 First high-speed response low-loss regulator main body 2 PNP output transistor 3 Control circuit 4 Feedback control division resistor R1 5 Feedback control division resistor R2 6 Base current adjustment resistor Rb 7 Input terminal (GND side) Reference Signs List 8 input terminal (Vin) 9 feedback terminal (Vref) of control circuit 3 10 output terminal (GND side) 11 output terminal (Vout) 12 power supply (circuit) 13 GND (earth) terminal 14 external aluminum electrolytic capacitor 15 organic semiconductor solid Electrolytic capacitor 16 Load 17 Second high-speed response low-loss regulator body 18 Capacitor 19 Third high-speed response low-loss regulator body 20 Parallel capacitor 21 Fourth high-speed response low-loss regulator body 22 PNP output transistor 2 base terminal 23 PNP output transistor 2 Collector terminal 24 PNP transistor 25 Series capacitor 26 Fifth high-speed response low-loss regulator main body 27 Power supply circuit 28 for control circuit 3 Power supply circuit connection terminal 29 Sixth high-speed response low-loss regulator main body 30 Capacitor 31 IC chip 32 PNP output Transistor 33 mounted with transistor 2 Frame 34 Insulating paste Td Recovery time (time until voltage starts to show a recovery tendency) Vp Peak voltage

   ────────────────────────────────────────────────── ─── Continuation of front page       (56) References JP-A-8-36425 (JP, A)                 JP-A-7-135362 (JP, A)                 JP-A-3-101158 (JP, A)                 JP-A-58-191414 (JP, A)                 JP-A-5-109974 (JP, A)                 JP-A-4-35058 (JP, A)

Claims (1)

(57) Claims: 1. A PNP output transistor, a control circuit for controlling a base current of the PNP output transistor, and the PNP output transistor.
A feedback split resistor that divides an output voltage of the NP output transistor and feeds back the feedback voltage to the control circuit, and controls a base current of the PNP output transistor according to a feedback amount from the feedback split resistor. In the regulator, a base current adjusting resistor for increasing a base current of the PNP output transistor and shortening a recovery time of a voltage response is connected between an emitter and a base of the PNP output transistor, and an IC including the control circuit. An organic semiconductor solid electrolytic capacitor connected in parallel to the output terminal of the high-speed response low-loss regulator is mounted between the bottom of the ground potential of the chip and the frame of the output potential, and the IC chip and the organic Semiconduct
High-speed response and low-loss regulation
A high-speed response low-loss regulator characterized by being connected in parallel between the output terminal and the GND terminal of the motor .