TW201640806A - Programmable power converter with reduced power loss and power-loss-reduced power transmission circuit thereof - Google Patents

Abstract

The present invention provides a programmable power converter with reduced power loss. The programmable power converter includes: a transformer, a power switch circuit, a primary side control circuit and a power-loss-reduction power transmission circuit. A tertiary winding of the transformer generates a high level bias voltage and a low level bias voltage according to a programmable output voltage at a relatively-higher-voltage-level node and a relatively-lower-voltage-level node of the tertiary winding, respectively. The power-loss-reduction power transmission circuit generates a power supply voltage according to one of the high level bias voltage and the low level bias voltage. When a voltage level of the programmable output voltage is relatively high, the power-loss-reduction power transmission circuit generates the power supply voltage according to the low level bias voltage. When a voltage level of the programmable output voltage is relatively low, the power-loss-reduction power transmission circuit performs voltage reduction operation according to the high level bias voltage, to generate the power supply voltage, thereby reducing the power loss.

Description

Programmable power converter capable of reducing power loss and power transmission circuit for reducing power loss therein

The invention relates to a programmable power converter capable of reducing power loss and a power transmission circuit for reducing power loss, in particular to a power transmission circuit for reducing power loss to provide power for achieving power loss reduction. Programmable power converter.

Please refer to FIG. 1, which shows a block diagram of a prior art programmable power converter. As shown in FIG. 1, the prior art programmable power converter 100 includes: a rectifier circuit 11, a transformer circuit 15, a power switch circuit 16, a feedback circuit 14, a primary side control circuit 13 and a second time Side control circuit 12. The AC voltage Vac is rectified by the rectifier circuit 11 to generate an input voltage VIN.

The programmable power converter 100 receives the input voltage VIN using the transformer circuit 15 therein, and converts the input voltage VIN into a programmable output voltage VOUT under the operation of the power switching circuit 16. The primary side control circuit 13 generates an operation signal S1 according to a current sensing signal Vcs and a feedback signal S3 generated by the feedback circuit 14 to operate the power switch 161 in the power switching circuit 16 to convert the input voltage VIN into a The program outputs voltage VOUT. The feedback signal S3 is related to the current actual value of the programmable output voltage VOUT.

The transformer circuit 15 includes a primary winding W1, a secondary winding W2 and a tertiary winding W3. The primary winding W1 is located on the primary side 15a of the transformer circuit 15 for receiving the input voltage VIN. The secondary winding W2 is located on the secondary side 15b of the transformer circuit 15 for generating a programmable output voltage VOUT at an output terminal OUT. The third winding W3 is located on the primary side 15a of the transformer circuit 15 for generating a supply voltage SBP' corresponding to the programmable output voltage VOUT based on the programmable output voltage VOUT. This supply voltage SBP' serves as a power source for the primary side control circuit 13.

The feedback signal secondary side control circuit 12 is coupled to the feedback circuit 14 for controlling the feedback circuit 14 to generate the feedback signal S3 according to the programmable output voltage VOUT. The secondary side control circuit 12 receives a set signal S2, which can adjust the feedback signal S3, thereby changing the ratio between the programmable output voltage VOUT and the feedback signal S3 to change the target value of the programmable output voltage VOUT.

In the architecture of the prior art programmable power converter 100, since the supply voltage SBP' is proportional to the programmable output voltage VOUT, when the programmable output voltage VOUT is set to a relatively high output voltage level The supply voltage SBP' will also have a relatively high voltage level correspondingly. As a result, when the power supply voltage required for the primary side control circuit 13 is smaller than the supply voltage SBP' having a relatively high voltage level, unnecessary power loss will be caused. In this case, the power loss can be expressed as: P (power) = SBP' (supply voltage) * IDD (output current)

In view of this, the present invention proposes a programmable power converter capable of reducing power loss, thereby reducing power loss.

In one aspect, the present invention provides a programmable power converter capable of reducing power loss for converting an input voltage into a programmable output voltage, wherein the programmable output voltage has at least one The relatively high output voltage level and a relatively low output voltage level, the programmable power converter capable of reducing power loss comprises: a transformer circuit comprising a primary winding, a primary winding and a third winding, The third winding has a first portion for receiving the input voltage, and a secondary winding for generating the programmable output voltage at an output, the third winding being used according to the The programmable output voltage generates a high level bias and a low level bias respectively at a relatively higher pressure position and a relatively lower pressure position of the third winding; a power switching circuit coupled to the main winding Turning on or off one of the power switches according to an operation signal to control the transformer circuit, thereby converting the input voltage into the programmable An output voltage; a primary side control circuit coupled to the power switch circuit for generating the operation signal; and a power transmission circuit for reducing power loss, coupling a supply of the third winding and the primary side control circuit Between the power terminals, for generating a supply voltage as the power of the primary side control circuit according to one of the high level bias and the low level bias, wherein the programmable output voltage is at the relatively high output When the voltage level is normal, the supply voltage is generated according to the low level bias voltage, and when the programmable output voltage is at the relatively low output voltage level, the step voltage adjustment is performed according to the high level bias voltage to generate the supply voltage. In order to reduce power loss.

In a preferred embodiment, the power transmission circuit for reducing power loss includes: an adjustment circuit coupled to the relatively higher voltage position of the third winding, wherein the adjustment circuit is configured to be based on the high level deviation Pressing, generating a first adjustment bias voltage; a first one-way conduction circuit coupled between the adjustment circuit and the supply power supply end of the primary side control circuit; and a second one-way conduction circuit coupled to The relatively lower pressure position of the third winding is between the supply terminal of the primary side control circuit, wherein the relatively lower pressure position of the third winding produces a second corresponding to the low level bias Adjusting the bias voltage; wherein the supply voltage is determined by the higher of the first adjustment bias voltage and the second adjustment bias voltage.

In a preferred embodiment, the second unidirectional conduction circuit includes a diode having an anode coupled to the relatively lower pressure position of the third winding, the cathode being coupled to the primary side control circuit The supply side of the supply.

In a preferred embodiment, the regulation circuit includes a Low Dropout Regulator (LDO).

In a preferred embodiment, the low-dropout linear regulator includes: a bipolar transistor having a current inflow end coupled to the relatively higher voltage position of the third winding, and a current outflow end coupled to the current output terminal The first one-way conducting circuit; and a Zener diode having an anode coupled to the ground and a cathode coupled to a control end of the bipolar transistor.

In another aspect, the present invention provides a power transmission circuit for reducing power loss for providing power to a primary side control circuit of a programmable power converter, and a primary side control circuit of the programmable power converter Generating an operation signal to turn on or off a power switch, thereby controlling a transformer circuit to convert an input voltage coupled to one of the main windings of the transformer circuit into a programmable output coupled to the primary winding of the transformer circuit a voltage, wherein the programmable output voltage has at least a relatively high output voltage level and a relatively low output voltage level, and wherein the transformer circuit includes a third winding, the third winding being responsive to the programmable The output voltage generates a high level bias and a low level bias respectively at a relatively higher pressure position and a relatively lower pressure position of the winding, the power transmission circuit for reducing power loss comprising: an adjustment circuit, and the The relatively high pressure position of the three windings is coupled, wherein the adjusting circuit is configured to generate a first adjustment according to the high level bias a first one-way conducting circuit coupled between the regulating circuit and a supply terminal of the primary side control circuit; and a second one-way conducting circuit coupled to the relatively lower voltage of the winding a position between the supply and the supply terminal of the primary side control circuit, wherein the relatively lower pressure position of the winding generates a second adjustment bias corresponding to the low level bias; wherein the power supply reduces power loss Transmitting circuit generates a supply voltage as a power source of the primary side control circuit according to one of the high level bias and the low level bias, wherein when the programmable output voltage is at the relatively high output voltage level, according to The low level bias voltage generates the supply voltage, and when the programmable output voltage is at the relatively low output voltage level, step-down regulation is performed according to the high level bias voltage to generate the supply voltage, thereby reducing power loss; Wherein, the supply voltage is determined by the higher of the first adjustment bias and the second adjustment bias.

In a preferred embodiment, the second unidirectional conduction circuit includes a diode having an anode coupled to the relatively lower pressure position of the winding, the cathode being coupled to the primary side control circuit. Supply power supply.

In a preferred embodiment, the conditioning circuit includes a low dropout linear regulator.

In a preferred embodiment, the low-dropout linear regulator includes: a bipolar transistor having a current inflow end coupled to the relatively higher voltage position of the winding, and a current outflow end coupled to the first A single-pass circuit; and a Zener diode having an anode coupled to the ground and a cathode coupled to a control end of the bipolar transistor.

In a preferred embodiment, the first unidirectional conduction circuit includes a diode having an anode coupled to the adjustment circuit and a cathode coupled to the supply terminal of the primary side control circuit.

The above and other technical contents, features and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments. The drawings in the present invention are schematic and are mainly intended to indicate the functional relationship between the devices and the components, and the shapes, sizes, and directions are not drawn according to the physical scale.

Please also refer to Figures 2 and 3. Fig. 2 is a block diagram showing a programmable power converter capable of reducing power loss according to an embodiment of the present invention. Figure 3 shows an embodiment of the feedback circuit 14 of the present invention.

In the present embodiment, the programmable power converter 200 capable of reducing the power loss is exemplified by an isolated type AC-DC converter, but the present invention is not limited thereto, and the program capable of reducing power loss can be programmed. The power converter 200 can also be other types of power converters. In an embodiment of an isolated AC to DC converter, the programmable power converter 200, which reduces power loss, can convert an input voltage VIN to a programmable output voltage VOUT. The programmable power converter 200 capable of reducing power loss comprises: a transformer circuit 25, a power transmission circuit 27 for reducing power loss, a power switching circuit 16, and a primary side control circuit 13. The power transmission circuit 27 that reduces power loss is, for example but not limited to, a circuit that can be a combination of discrete components, or an integrated circuit, or integrated into the primary side control circuit 13. In addition, the programmable power converter 200 capable of reducing power loss may optionally include a secondary side control circuit 12, a feedback circuit 14, and a current sensing resistor Rcs. The isolated AC/DC converter is a circuit familiar to those skilled in the art, so other circuit details are omitted except for the parts related to the present case, so that the drawing is simple (how to reduce the power transmission circuit 27 for reducing power loss) The details and characteristics of the power loss of the programmable power converter 200 of the invention which can reduce the power loss are detailed later.

The programmable power converter 200, which reduces power loss, utilizes the transformer circuit 25 therein to receive the input voltage VIN and convert it to a programmable output voltage VOUT. In an embodiment, the input voltage VIN can be generated by an AC power source Vac via a rectifier circuit 11. In an embodiment, the rectifier circuit 11 is, for example but not limited to, a bridge rectifier circuit.

In the present embodiment, the transformer circuit 25 includes a main winding W1, a primary winding W2 and a third winding W30. The primary winding W1 is located on the primary side 25a of the transformer circuit 25 for receiving the input voltage VIN. The secondary winding W2 is located on the secondary side 25b of the transformer circuit 25 for generating a programmable output voltage VOUT at an output terminal OUT. In this embodiment, the programmable output voltage VOUT can be set to have at least a relatively high output voltage level and a relatively low output voltage level (ie, the programmable output voltage VOUT can be switched to more than two Target values such as, but not limited to, 12V and 5V).

In the present embodiment, the third winding W30 is located on the primary side 25a of the transformer circuit 25. In an embodiment, the third winding W30 is, for example but not limited to, a winding that can be a center tap. In an embodiment with a center tapped winding, the third winding W30 has a first portion W31 and a second portion W32. The node in which the first portion W31 and the second portion W32 are connected to each other is a relatively lower pressure position N2 of the third winding W30. That is, one end of the second portion W32 of the third winding W30 is grounded, and the other end is a relatively low pressure position N2. One end of the first portion W31 of the third winding W30 is a relatively lower pressure position N2, and the other end is a relatively higher pressure position N1 of the third winding W30. In the embodiment with the intermediate tapped winding, the third winding W30 generates a high level bias HBP and a low level bias LBP at a relatively higher pressure position N1 and a relatively lower pressure position N2 of the third winding W30, respectively, and The voltage level of the high level bias voltage HBP and the low level bias voltage LBP is related to the level of the programmable output voltage VOUT.

The power switch circuit 16 is coupled to the main winding W1 of the transformer circuit 25 for turning on or off the power switch 161 in the power switch circuit 16 according to an operation signal S1 to control the current flowing through the main winding W1. To induce the winding W2, the input voltage VIN is converted to a programmable output voltage VOUT.

The primary side control circuit 13 is configured to generate an operation signal S1 (outputting the operation signal S1 from its operation signal terminal GATE) to control the power switch 161 in the power switch circuit 16 to be turned on or off. In this embodiment, the primary side control circuit 13 generates the operation signal S1 according to the current sensing signal Vcs received from the current sensing terminal CS and the generated feedback signal S3 received from the feedback terminal COMP. .

The feedback circuit 14 is coupled to the secondary winding W2 of the transformer circuit 25 for generating a feedback signal S3 according to the programmable output voltage VOUT and a set signal S2. The secondary side control circuit 12 is coupled to the feedback circuit 14 and the secondary winding W2 of the transformer circuit 25 for generating the setting signal S2 according to the programmable output voltage VOUT.

The programmable power converter 200, which can reduce the power loss, is exemplified by an isolated AC/DC converter in this embodiment. Therefore, in an embodiment, the feedback circuit 14 can be an isolated feedback circuit. For example, but not limited to, it may be an optical coupling circuit as shown in FIG. 3, but the invention is not limited thereto. As other types of power converters, the feedback circuit 14 can be other types of feedback circuits (such as, but not limited to, voltage divider resistors).

The power transmission circuit 27 for reducing the power loss is coupled between the third winding W30 of the transformer circuit 25 and a supply terminal VDD of the primary side control circuit 13. The power transmission circuit 27 for reducing power loss of the present embodiment can generate a supply voltage SBP as a power source of the primary side control circuit 13 according to one of the high level bias voltage HBP and the low level bias voltage LBP.

Please refer to Figures 4 and 5. Figure 4 shows a specific embodiment of the power transfer circuit 27 of the present invention for reducing power loss. Figure 5 shows a more specific embodiment of the power transfer circuit 27 of the present invention for reducing power loss.

As shown in FIG. 4, the power transmission circuit 27 for reducing power loss of the present embodiment includes an adjustment circuit 271, a unidirectional conduction circuit 272, and a unidirectional conduction circuit 273.

The relatively higher pressure position N1 of the third winding W30 is coupled to the adjustment circuit 27, and the other end of the third winding W30 is grounded. In an embodiment, the adjustment circuit 271 is, for example but not limited to, a Low Dropout Regulator (LDO). In one embodiment of a low dropout linear regulator (LDO), as shown in FIG. 5, the conditioning circuit 271 can include a bipolar transistor 2712 and a Zener diode 2711. The current inflow end of the bipolar transistor 2712 is coupled to the relatively higher voltage position N1 of the third winding W30, and the current outflow end of the bipolar transistor 2712 is coupled to the unidirectional conduction circuit 272. The anode of the Zener diode 2711 is coupled to the ground, and the cathode of the Zener diode 2711 is coupled to a control terminal of the bipolar transistor 2712. There are many other implementations for low dropout linear regulators, and Figure 5 is only an example.

As shown in FIG. 4, the one-way conduction circuit 272 is coupled between the adjustment circuit 27 and the supply terminal VDD of the primary side control circuit 13. As shown in FIG. 5, in one embodiment, the unidirectional conduction circuit 272 can include, for example and without limitation, a diode 2721. The anode of the diode 2721 is coupled to the regulating circuit, and the cathode of the diode 2721 is coupled to the supply terminal VDD of the primary side control circuit 13.

As shown in FIG. 4, the one-way conduction circuit 273 is coupled between the relatively lower voltage position N2 of the third winding W30 and the supply power terminal VDD of the primary side control circuit 13. As shown in FIG. 5, in one embodiment, the unidirectional conduction circuit 273 can include, for example but not limited to, a diode 2731. The anode of the diode 2731 is coupled to the relatively lower pressure position N2 of the third winding W30, and the cathode of the diode 2731 is coupled to the supply terminal VDD of the primary side control circuit 13.

The adjustment circuit 27 performs a step-down adjustment according to the high level bias voltage HBP to generate a first adjustment bias voltage VD1. The low level bias voltage LBP generates a second regulation bias voltage VD2 corresponding to the low level potential bias LBP. By the action of the unidirectional conduction circuit 272 and the unidirectional conduction circuit 273, the supply voltage is determined by the higher of the first adjustment bias voltage VD1 and the second regulation bias voltage VD2.

Regarding how the power transmission circuit 27 of the present invention for reducing the power loss reduces the power loss of the programmable power converter 200 of the present invention which can reduce the power loss, please refer to the description of FIG. 6 and simultaneously compare FIG. 2 and FIG. 4 with Figure 5. Figure 6 shows the relationship between the programmable output voltage VOUT, the first regulated bias voltage VD1, the second regulated bias voltage VD2, and the supply voltage SBP.

As shown in FIG. 6, since the high level bias voltage HBP and the low level bias LBP are taken from the third winding, and the programmable output voltage VOUT is taken from the secondary winding, the high level bias voltage HBP is related to the low level bias LBP. The programmable output voltage VOUT. As previously mentioned, the programmable output voltage VOUT can be set to a relatively high output voltage level or a relatively low output voltage level. When the programmable output voltage VOUT is at a relatively low output voltage level (the left half of Fig. 6), for example, when the high level bias HBP is at point A shown in Fig. 6, according to the present According to the invention, the adjusting circuit 271 steps-down the voltage level of the point A (high level bias voltage HBP) to generate a first regulating bias voltage VD1 as indicated by point B in FIG. For example, in the case of the embodiment of Fig. 5, the first adjustment bias voltage VD1 is equal to the Zener voltage V2711 of the Zener diode 2711 minus the base emitter voltage difference V2712 of the bipolar transistor 2712. That is, the first adjustment bias voltage VD1 can be expressed as: VD1=V2711- V2712

Since the Zener voltage V2711 and the base emitter voltage difference V2712 are constant values, the first adjustment bias voltage VD1 is a constant value. In this way, when the programmable output voltage VOUT is at a relatively low output voltage level (the left half of FIG. 6), regardless of the voltage level of the high level bias voltage HBP, the high level bias The HBP is stepped down by the conditioning circuit 27 to produce a fixed voltage level (i.e., the first regulated bias voltage VD1).

At this time, the supply voltage SBP is equal to the first regulated bias voltage VD1 minus the voltage drop of the unidirectional conduction circuit 272; for example, in the case of the embodiment of Fig. 5, the supply voltage SBP is equal to the first regulated bias voltage VD1 minus The forward voltage V2721 of the diode 2721 is subtracted. That is, when the programmable output voltage VOUT is at a relatively low output voltage level (the left half of Fig. 6), the supply voltage SBP can be expressed by the following equation: SBP=VD1-V2721=(V2711- V2712) - V2721 This supply voltage SBP should be greater than or equal to the operating voltage required by the primary side control circuit 13.

On the other hand, when the programmable output voltage VOUT is at a relatively high output voltage level (the right half of FIG. 6), for example, when the low level bias LBP is at point D shown in FIG. At this time, the power transmission circuit 27 that reduces the power loss generates the second adjustment bias voltage VD2 according to the low level bias LBP.

That is, in the case where the programmable output voltage VOUT is at a relatively high output voltage level (the right half of Fig. 6), the supply voltage SBP can be expressed as:

SBP=LBP - V2731 where V2731 is the forward voltage of the diode 2731.

In the illustrated embodiment, the second regulated bias voltage VD2 is equal to the low level biased LBP, but in other embodiments, the low leveling bias LBP may also be subjected to a voltage drop to produce a second regulated bias voltage VD2.

As described above, according to the present invention, the supply voltage SBP is determined by the higher of the first adjustment bias voltage VD1 and the second regulation bias voltage VD2, as indicated by the thick solid line in FIG. The present invention can reduce power consumption compared to the prior art for the following reasons. In the prior art, the power supply of the primary side control circuit 13 is provided with a third winding, and the power supply is provided with a high level bias voltage HBP corresponding to Fig. 6. In the prior art, the power supply cannot be supplied with the low level bias LBP because the primary side control circuit 13 will not operate when the low level bias LBP is too low (e.g., point C in Fig. 6). Accordingly, the prior art provides a power supply with a high level biased HBP, and the present invention provides a power supply with a thick solid line in FIG. 6, which is lower in voltage and multiplied by a current, The invention thus reduces power consumption.

The present invention has been described with reference to the preferred embodiments thereof, and the present invention is not intended to limit the scope of the present invention. In the same spirit of the invention, various equivalent changes can be conceived by those skilled in the art. All of these can be derived analogously to the teachings of the present invention. The various embodiments illustrated are not limited to separate applications, and may be combined applications, such as but not limited to, the two embodiments are used in combination, or the partial circuits of one of the embodiments are substituted for the corresponding circuits of another embodiment. Therefore, the scope of the invention should be construed as covering the above and all other equivalents. In addition, any embodiment of the present invention is not required to achieve all of the objects or advantages, and therefore, any one of the claims is not limited thereto.

[study]
100‧‧‧Knowledge programmable power converter
11‧‧‧Learning rectifier circuit
12‧‧‧ Known secondary side control circuit
13‧‧‧ Known primary side control circuit
14‧‧‧Custom feedback circuit
15‧‧‧General transformer circuit
15a‧‧‧I know the primary side
15b‧‧‧Traditional secondary side
16‧‧‧Preferred power switch circuit
161‧‧‧Law power switch
CS‧‧‧Issued current sensing end
COMP‧‧‧French feedback
GATE‧‧‧Learning operation signal end
GND‧‧‧Learing ground potential
IDD‧‧‧I know the output current
S1‧‧‧Study operation signal
S2‧‧‧Custom setting signal
S3‧‧‧Study feedback signal
SBP'‧‧‧Professional supply voltage
OUT‧‧‧Chinese output
V2711‧‧‧ Zener voltage
V2712‧‧‧ Forward voltage
Vac‧‧‧Knowledge AC power supply
Vcs‧‧‧Issued current sensing signal
VDD‧‧‧Knowledge supply power supply
VIN‧‧‧I know the input voltage
VOUT‧‧‧Knowledge programmable output voltage
W1‧‧‧Knowledge main winding
W2‧‧‧ learned secondary winding
W3‧‧‧Knowledge third winding [present invention]
200‧‧‧Programmable power converters with reduced power loss
11‧‧‧Rectifier circuit
12‧‧‧secondary control circuit
13‧‧‧primary side control circuit
14‧‧‧Feedback circuit
25‧‧‧Transformer circuit
25a‧‧‧primary side
25b‧‧‧second side
16‧‧‧Power Switch Circuit
161‧‧‧Power switch
27‧‧‧Power transmission circuit for reducing power loss
271‧‧‧ adjustment circuit
2711‧‧‧Bipolar transistor
2712‧‧‧Zina diode
272‧‧‧Single-conduction circuit
2721‧‧‧dipole
273‧‧‧ unidirectional conduction circuit
2731‧‧‧ diode
A, B, C, D‧‧‧ voltage level
CS‧‧‧current sensing end
COMP‧‧‧Feedback
D3‧‧‧ diode
GATE‧‧‧Operation signal end
GND‧‧‧ Ground potential
HBP‧‧‧ high standard bias
IDD‧‧‧Output current
LBP‧‧‧low standard bias
N1‧‧‧ relatively high pressure position
N2‧‧‧ relatively low pressure position
S1‧‧‧ operation signal
S2‧‧‧ setting signal
S3‧‧‧ feedback signal
T1~T2‧‧‧ time
SBP‧‧‧ supply voltage
OUT‧‧‧ output
Vac‧‧‧AC power supply
Vcs‧‧‧ current sensing signal
VDD‧‧‧ supply power supply
VD1‧‧‧First adjustment bias
VD2‧‧‧second adjustment bias
VIN‧‧‧ input voltage
VOUT‧‧‧programmable output voltage
W1‧‧‧ main winding
W2‧‧‧ secondary winding
W30‧‧‧ Third winding
W31‧‧‧Part I
W32‧‧‧ Part II

Figure 1 shows a block diagram of a prior art programmable power converter. Fig. 2 is a block diagram showing a programmable power converter capable of reducing power loss according to an embodiment of the present invention. Figure 3 shows an embodiment of the feedback circuit 14 of the present invention. Figure 4 shows a specific embodiment of the power transfer circuit 27 of the present invention for reducing power loss. Figure 5 shows a more specific embodiment of the power transfer circuit 27 of the present invention for reducing power loss. Figure 6 shows that the supply voltage of the present invention is determined by the higher of the first regulated bias and the second regulated bias.

200‧‧‧Programmable power converters with reduced power loss

11‧‧‧Rectifier circuit

12‧‧‧secondary control circuit

13‧‧‧primary side control circuit

14‧‧‧Feedback circuit

25‧‧‧Transformer circuit

25a‧‧‧primary side

25b‧‧‧second side

16‧‧‧Power Switch Circuit

161‧‧‧Power switch

27‧‧‧Power transmission circuit for reducing power loss

271‧‧‧ adjustment circuit

272‧‧‧Single-conduction circuit

273‧‧‧ unidirectional conduction circuit

CS‧‧‧current sensing end

COMP‧‧‧ target console

D3‧‧‧ diode

GATE‧‧‧Operation signal end

GND‧‧‧ Ground potential

HBP‧‧‧ high standard bias

IDD‧‧‧Output current

LBP‧‧‧low standard bias

N1‧‧‧ relatively high pressure position

N2‧‧‧ relatively low pressure position

S1‧‧‧ operation signal

S2‧‧‧ setting signal

S3‧‧‧ feedback signal

SBP‧‧‧ supply voltage

OUT‧‧‧ output

Vac‧‧‧AC power supply

Vcs‧‧‧ current sensing signal

VDD‧‧‧ supply power supply

VD1‧‧‧First adjustment bias

VD2‧‧‧second adjustment bias

VIN‧‧‧ input voltage

VOUT‧‧‧programmable output voltage

W1‧‧‧ main winding

W2‧‧‧ secondary winding

W30‧‧‧ Third winding

W31‧‧‧Part I

W32‧‧‧ Part II

Claims (11)

A programmable power converter capable of reducing power loss for converting an input voltage into a programmable output voltage, wherein the programmable output voltage has at least a relatively high output voltage level and a The relatively low output voltage level, the programmable power converter capable of reducing power loss comprises: a transformer circuit comprising a primary winding, a primary winding and a third winding, the primary winding receiving the input voltage, The secondary winding is configured to generate the programmable output voltage at an output, and the third winding is configured to generate a voltage at the relatively higher pressure position and a relatively lower pressure position of the third winding according to the programmable output voltage. a high level bias voltage and a low level bias voltage; a power switching circuit coupled to the main winding for turning on or off one of the power switches according to an operation signal to control the transformer circuit, and thereby inputting the input voltage Converting to the programmable output voltage; a primary side control circuit coupled to the power switch circuit for generating the operation signal; And a power transmission circuit for reducing power loss, coupled between the third winding and a supply terminal of the primary side control circuit, for generating one according to the high level bias and the low level bias Supplying voltage as a power source of the primary side control circuit, wherein when the programmable output voltage is at the relatively high output voltage level, the supply voltage is generated according to the low level bias voltage, and when the programmable output voltage is at the relative At a lower output voltage level, buck regulation is performed according to the high level bias to generate the supply voltage, thereby reducing power loss. A programmable power converter capable of reducing power loss as described in claim 1, wherein the power transmission circuit for reducing power loss comprises: an adjustment circuit coupled to the relatively higher voltage position of the third winding, The adjusting circuit is configured to generate a first adjusting bias according to the high level bias; a first one-way conducting circuit coupled between the adjusting circuit and the supply end of the primary side control circuit; And a second unidirectional conduction circuit coupled between the relatively lower pressure position of the third winding and the supply power terminal of the primary side control circuit, wherein the relatively lower pressure position of the third winding Generating a second adjustment bias corresponding to the low level bias; wherein the supply voltage is determined by the higher of the first adjustment bias and the second adjustment bias. The programmable power converter of claim 2, wherein the first unidirectional conduction circuit comprises a diode, the anode of which is coupled to the regulating circuit, and the cathode is coupled to the cathode The supply side of the primary side control circuit. A programmable power converter capable of reducing power loss as described in claim 2, wherein the second unidirectional pass circuit comprises a diode having an anode coupled to the relatively lower voltage of the third winding The cathode is coupled to the supply end of the primary side control circuit. A programmable power converter capable of reducing power loss as described in claim 2, wherein the regulating circuit comprises a Low Dropout Regulator (LDO). A programmable power converter capable of reducing power loss as described in claim 5, wherein the low dropout linear regulator comprises: a bipolar transistor having a current inflow end coupled to the third winding a relatively high voltage position, the current outflow end is coupled to the first one-way conducting circuit; and a Zener diode having an anode coupled to the ground and a cathode coupled to the bipolar transistor Control terminal. A power transmission circuit for reducing power loss for supplying power to a primary side control circuit of a programmable power converter, wherein a primary side control circuit of the programmable power converter generates an operation signal to turn a power on or off a switch, thereby controlling a transformer circuit to convert an input voltage coupled to one of the main windings of the transformer circuit into a programmable output voltage coupled to the primary winding of the transformer circuit, wherein The program output voltage has at least a relatively high output voltage level and a relatively low output voltage level, and wherein the transformer circuit includes a third winding, the third winding is based on the programmable output voltage One of the windings generates a high level bias and a low level bias respectively at a relatively high pressure position and a relatively low pressure position, the power transmission circuit for reducing power loss comprising: an adjustment circuit, the opposite of the third winding The higher voltage position is coupled, wherein the adjusting circuit is configured to generate a first adjustment bias according to the high level bias; a first unidirectional conduction circuit coupled between the adjustment circuit and a supply terminal of the primary side control circuit; and a second unidirectional conduction circuit coupled to the relatively lower pressure position of the winding and the Between the supply power terminals of the primary side control circuit, wherein the relatively lower pressure position of the winding generates a second adjustment bias corresponding to the low level bias; wherein the power transmission circuit for reducing power loss is based on One of the high level bias and the low level bias generates a supply voltage as a power source for the primary side control circuit, wherein the programmable output voltage is at the relatively high output voltage level, according to the low level The bias voltage generates the supply voltage, and when the programmable output voltage is at the relatively low output voltage level, the buck regulation is performed according to the high level bias voltage to generate the supply voltage, thereby reducing power loss; wherein The supply voltage is determined by the higher of the first regulated bias and the second regulated bias. The power transmission circuit for reducing power loss according to claim 7 , wherein the first unidirectional conduction circuit comprises a diode, an anode is coupled to the adjustment circuit, and a cathode is coupled to the primary side control The supply end of the circuit. The power transmission circuit for reducing power loss as described in claim 7, wherein the second unidirectional conduction circuit comprises a diode having an anode coupled to the relatively lower pressure position of the winding, and a cathode coupling Connected to the supply power terminal of the primary side control circuit. A power transmission circuit for reducing power loss as described in claim 7 wherein the adjustment circuit comprises a Low Dropout Regulator (LDO). The power transmission circuit for reducing power loss according to claim 10, wherein the low dropout linear regulator comprises: a bipolar transistor having a current inflow end coupled to the relatively higher pressure position of the winding, The current outflow end is coupled to the first one-way conducting circuit; and a Zener diode having an anode coupled to the ground and a cathode coupled to a control end of the bipolar transistor.