CN202178715U - AC-DC power conversion chip and power conversion circuit - Google Patents

AC-DC power conversion chip and power conversion circuit Download PDF

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Publication number
CN202178715U
CN202178715U CN2011202802598U CN201120280259U CN202178715U CN 202178715 U CN202178715 U CN 202178715U CN 2011202802598 U CN2011202802598 U CN 2011202802598U CN 201120280259 U CN201120280259 U CN 201120280259U CN 202178715 U CN202178715 U CN 202178715U
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China
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voltage
output
circuit
power
input
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CN2011202802598U
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Chinese (zh)
Inventor
吴飞
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Limited company of Fu Man electronics group of Shenzhen
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Nanshan Branch Company Shenzhen Fuman Electronic Co Ltd
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Abstract

The utility model is applied to the field of integrated circuit and provides an AC-DC (Alternating Current-Direct Current) power conversion chip and a power conversion circuit; the AC-DC power conversion chip comprises a ground pin, a band-gap reference unit and a pulse width modulation unit, and further comprises a power pin, a direct-current output pin, a voltage stabilizing unit having an input end connected with an internal connecting end of the power pin and an output end connected with the input end of the pulse width modulation unit, and a comparison unit having a first input end connected with the output end of the band-gap reference unit, a second input end connected with the internal connecting end of the direct-current output pin, and the output end connected with the input end of the pulse width modulation unit. The AC-DC power conversion chip and the power conversion circuit provided by the utility model receive a feedback signal from the power pin directly by the voltage stabilizing unit, and detect from the direct-current output pin by the comparison unit to output a low DC voltage; as three pins of the AC-DC power conversion chip are provided, manufacturing cost is reduced effectively, packaging process is simplified and packaging cost is reduced.

Description

A kind of AC-DC power conversion chip and power-switching circuit
Technical field
The utility model belongs to integrated circuit fields, relates in particular to a kind of AC-DC power conversion chip and power-switching circuit.
Background technology
In daily life, exchange the commentaries on classics DC circuit and be applied to usually in the fields such as charger, adapter, light fixture, at present traditional AC-DC power conversion chip adopts the encapsulation of five pin SOT23 (Small OutlineTransistor, small outline transistor) formula usually.
Fig. 1 shows the AC-DC power conversion chip of existing five pin encapsulation, comprising grounding pin 11, power pins 12, direct current output pin 13, feedback voltage pin 14, input pin 15, voltage regulation unit 16, modulating unit 17, reference cell 18 and comparing unit 19.
The input of voltage regulation unit 16 is connected with the inside input of power pins 12; The feedback end of voltage regulation unit 16 is connected with the inside link of feedback voltage pin 14; The output of voltage regulation unit 16 is connected with the input of modulating unit 17; The first input end of comparing unit 19 is connected with the output of reference cell 18; Second input of comparing unit 19 is connected with the inside link of input pin 15, and the output of comparing unit 19 is connected with the control end of modulating unit 17, and the output of modulating unit 17 is connected with the inside link of direct current output pin 13.
Starting resistor inputs to voltage regulation unit 16 through power pins 12; It is the power supply of AC-DC power conversion chip 1 internal module that voltage regulation unit 16 converts the starting resistor of this high voltage direct current into internal supply voltage; Modulation circuit 17 is a low-voltage dc voltage with this voltage transitions further; Export power-switching circuit to through direct current output pin 13, input pin 15 is used for through the external power source change-over circuit output low-voltage dc voltage being sampled, and the reference voltage comparison that sampled signal and reference cell 18 are provided; To modulation circuit 17 output control signals, to export the amplitude stability of low-voltage dc voltage through the pulse width modulation of control modulation circuit.
Fig. 2 shows the power-switching circuit of the AC-DC power conversion chip of existing five pin encapsulation, comprising:
AC-DC power conversion chip 1, current rectifying and wave filtering circuit 21, start-up circuit 22, switching circuit 23, transformer 24, feedback circuit 25 and filter circuit 26.
The input of current rectifying and wave filtering circuit 21 connects AC power; The output of current rectifying and wave filtering circuit 21 is connected with the input of start-up circuit 22; The output of start-up circuit 22 is connected with the outside link of the power pins 12 of AC-DC power conversion chip 1; The input of switching circuit 23 is connected with the outside link of AC-DC power conversion chip 1 direct current output pin 13; The sampling end of switching circuit 23 is connected with the outside link of the input pin 15 of AC-DC power conversion chip 1; The earth terminal of switching circuit 23 is connected with the outside link of the grounding pin of AC-DC power conversion chip 1, common ground, and the output of switching circuit 23 is connected with the elementary winding of transformer 24; The auxiliary winding of transformer 24 is connected with the input of feedback circuit 25; The output of feedback circuit 25 is connected with the outside link of the feedback voltage pin 14 of AC-DC power conversion chip 1, and the secondary winding of transformer 24 is connected with the input of filter circuit 26, and the output of filter circuit 26 is the output of power-switching circuit of the AC-DC power conversion chip 1 of this five pin encapsulation.
AC power is through becoming the direct current of concussion high pressure behind the current rectifying and wave filtering circuit 21; This high voltage direct current is through charging to start-up circuit to start chip 1; Make the direct current output pin 13 output low-voltage DCs of chip 1; This low-voltage DC is exported to the elementary winding of transformer 24 through switch element 23, by secondary winding this voltage is passed to filter circuit 26, is undertaken becoming this power-switching circuit output voltage behind the secondary filtering by 26 pairs of these low-voltage DCs of filter circuit.
Feedback circuit 25 is sensed electric current through the auxiliary winding of transformer 24 and is fed back to voltage regulation unit 16 by feedback voltage pin 14, and voltage regulation unit 16 is stable through this feedback voltage adjustment chip internal supply power voltage.
Switching circuit 23 converts direct current output pin 13 output low-voltage DCs into sampled signal and exports to comparing unit 19 through signal controlling pin 15, by the stability of comparing unit 19 according to sampled signal control modulation circuit 17 adjustment output low-voltage DCs.
Because the structure of five pins of above-mentioned AC-DC power conversion chip makes this chip can only select the encapsulation of SOT23 formula at present for use, still, SOT23 formula packaging technology is complicated, and cost is high, is unfavorable for the extensive use of AC-DC power conversion chip.
The utility model content
The purpose of the utility model embodiment is to provide a kind of AC-DC power conversion chip, is intended to solve the AC-DC power conversion chip cost of manufacture height of existing five leg structures, the packaging technology complicated problems.
The utility model embodiment is achieved in that a kind of AC-DC power conversion chip, comprises grounding pin, band-gap reference unit and pwm unit, and said chip also comprises:
The power pins of input starting resistor or input chip exterior supply power voltage and feedback signal;
Export low-voltage dc voltage, and said low-voltage dc voltage is imported the direct current output pin of said chip as sampled signal;
Convert said starting resistor or chip exterior supply power voltage into the chip internal supply power voltage; And according to the voltage regulation unit of the amplitude of said feedback signal adjustment chip internal supply power voltage; The input of said voltage regulation unit is connected with the inside link of said power pins, and the output of said voltage regulation unit is connected with the input of said pwm unit;
The reference voltage that said sampled signal and said band-gap reference unit are provided relatively; Comparing unit to said pwm unit output comparison control signal; The first input end of said comparing unit is connected with the output of said band-gap reference unit; Second input of said comparing unit is connected with the inside link of said direct current output pin, and the output of said comparing unit is connected with the input of said pwm unit.
Further, said chip adopts the encapsulation of transistor T O-92 formula tripod.
Another purpose of the utility model embodiment is to provide a kind of power-switching circuit that adopts said chip, comprises rectification circuit, filter capacitor C1, and said power-switching circuit also comprises:
When power supply electrifying, charge, to the start-up circuit of said chip output starting resistor, the input of said start-up circuit is connected with the end of said filter capacitor C1, and the output of said start-up circuit is connected with the bringing-out of said power pins;
Conducting when said chip is exported said low-voltage dc voltage; The switching circuit of output conducting electric current; The input of said switching circuit is connected with the outside link of said direct current output pin, the outside link common ground of the earth terminal of said switching circuit and said grounding pin;
With said conducting current conversion is output voltage; And be the transformer T1 that said chip provides said supply power voltage and feedback signal; The end of the same name of the elementary winding N1 of said transformer T1 is connected with the input of said start-up circuit; The different name end of said elementary winding N1 is connected with the output of said switching circuit; The end of the same name of the secondary winding N2 of said transformer T1 is the output negative pole of said power-switching circuit, and the different name end of the secondary winding N2 of said transformer T1 is the output cathode of said power-switching circuit, the end ground connection of the same name of the auxiliary winding N3 of said transformer T1;
Transmit the forward voltage in said supply power voltage and the feedback signal; Resist the diode D6 of reverse voltage; The anode of said diode D6 is connected with the different name end of the auxiliary winding N3 of said transformer T1, and the negative electrode of said diode D6 is connected with the bringing-out of said power pins;
Reduce the filter circuit of the ripple in the low-voltage dc voltage of sensing; The positive input terminal of said filter circuit is connected with the different name end of the secondary winding N2 of said transformer T1; The negative input end of said filter circuit is connected with the end of the same name of the secondary winding N2 of said transformer T1; The positive output end of said filter circuit is the output cathode of said power-switching circuit, and the negative output terminal of said filter circuit is the output negative pole of said power-switching circuit.
Further, said start-up circuit comprises:
Resistance R 1 and capacitor C 3;
One end of said resistance R 1 is the input of said start-up circuit, and the other end of said resistance R 1 is connected with an end of said capacitor C 3, and its link is the output of said start-up circuit, the other end ground connection of said capacitor C 3.
Further, said switching circuit comprises:
Triode Q1 and resistance R 3;
The base stage of said triode Q1 is the input of said switching circuit; The output of the very said switching circuit of the current collection of said triode Q1; The emitter of said triode Q1 is connected with an end of said resistance R 3, and the other end of said resistance R 3 is the earth terminal of said switching circuit.
Further, said filter circuit comprises:
Diode D7, capacitor C 4 and resistance R 4;
Said capacitor C 4 is parallelly connected with said resistance R 4; Said capacitor C 4 is the negative input end and the negative output terminal of said filter circuit with a common port of said resistance R 4 simultaneously; Said capacitor C 4 is the positive output end of said filter circuit with another common port of said resistance R 4; Be connected with the negative electrode of said diode D7, the anode of said diode D7 is the positive input terminal of said filter circuit.
Further, said power-switching circuit also comprises:
Absorb the absorption circuit of leakage inductance current spike voltage, the input of said absorption circuit is connected with the different name end of the elementary winding N1 of said transformer T1, and the output of said absorption circuit is connected with the end of the same name of the elementary winding N1 of said transformer T1.
Further, said absorption circuit comprises:
Utmost point pipe D5, capacitor C 2 and resistance R 2;
Said resistance R 2 is parallelly connected with said capacitor C 3; Said resistance R 2 is the output of said absorption circuit with a common port of said capacitor C 3; Said resistance R 2 is connected with the negative electrode of said diode D5 with another common port of said capacitor C 3, and the anode of said diode D5 is the input of said absorption circuit.
In the utility model embodiment; Through changing AC-DC power conversion chip internal module structure and external power source change-over circuit; Make and only can realize that through power pins, grounding pin and direct current output pin alternating current arrives galvanic conversion, effectively reduce cost of manufacture, and this structure is applicable to the encapsulation of TO92 formula; Further simplify packaging technology, helped the extensive use of AC-DC power conversion chip.
Description of drawings
Fig. 1 is the structure chart of the AC-DC power conversion chip of existing five pin encapsulation;
Fig. 2 is the structure chart of power-switching circuit of the AC-DC power conversion chip of existing five pin encapsulation;
The structure chart of the AC-DC power conversion chip that Fig. 3 provides for the utility model one embodiment;
The structure chart of the power-switching circuit of the AC-DC power conversion chip that Fig. 4 provides for the utility model one embodiment;
The exemplary circuit structure chart of the power-switching circuit of the AC-DC power conversion chip that Fig. 5 provides for the utility model one embodiment.
Embodiment
For the purpose, technical scheme and the advantage that make the utility model is clearer,, the utility model is further elaborated below in conjunction with accompanying drawing and embodiment.Should be appreciated that specific embodiment described herein only in order to explanation the utility model, and be not used in qualification the utility model.
The utility model embodiment utilizes voltage regulation unit directly from the power pins receiving feedback signals, and directly detects the output low-voltage dc voltage from the direct current output pin through comparing unit, and the pin of AC-DC power conversion chip is reduced to three.
Fig. 3 illustrates the structure of the AC-DC power conversion chip that the utility model embodiment provides, and for the ease of explanation, only shows the part relevant with the utility model.
As the AC-DC power conversion chip 3 that the utility model one embodiment provides, comprise grounding pin 31, band-gap reference unit 36 and pwm unit 35, this chip 3 also comprises:
The power pins 32 of input starting resistor or input chip exterior supply power voltage and feedback signal;
The output low-voltage dc voltage, and with the direct current output pin 33 of this low-voltage dc voltage as sampled signal input AC-DC power conversion chip 3;
Convert starting resistor or chip exterior supply power voltage into the chip internal supply power voltage; And according to the voltage regulation unit 34 of the amplitude of feedback signal adjustment chip internal supply power voltage; The input of this voltage regulation unit 34 is connected with the inside link of power pins 32, and the output of voltage regulation unit 34 is connected with the input of pwm unit 35;
The reference voltage that sampled signal and band-gap reference unit 36 are provided relatively; The comparing unit 37 of pulse-width modulated unit 35 output comparison control signals; The first input end of this comparing unit 37 is connected with the output of band-gap reference unit 36; Second input of comparing unit 37 is connected with the inside link of direct current output pin 33, and the output of comparing unit 37 is connected with the input of pwm unit 35.
As the utility model one embodiment; Grounding pin 31 is drawn chip with the chip internal earth terminal; Be connected with ground wire; Behind the alternating voltage process rectifying and wave-filtering of input, form the high-voltage dc signal of concussion, this high-voltage dc signal inputs to voltage regulation unit 34 as the starting resistor of AC-DC power conversion chip 3 through power pins 32, and it is chip 3 in-line powers that voltage regulation unit 34 converts starting resistor into stable direct current supply voltage; Pwm unit 35 converts this internal supply voltage the low-voltage dc voltage of certain amplitude into, and exports chip exterior to through direct current output pin 33.
The low-voltage dc voltage of output can produce induced current as feedback signal through transformer; Input to voltage regulation unit 34 through power pins 32; Voltage regulation unit 34 is according to the amplitude of feedback signal adjustment chip internal supply power voltage, to export stable chip internal supply power voltage.
The low-voltage dc voltage of output also simultaneously inputs to comparing unit 37 as sampled signal; Comparing unit 37 compares the reference voltage of this sampled signal and 36 generations of band-gap reference unit; When sampled signal during greater than reference voltage, comparing unit 37 makes pwm unit 35 reduce the duty ratio of pulse width modulating signal to pwm unit 35 output comparison control signals; And then reduce the amplitude of output dc voltage; When sampled signal during less than reference voltage, comparing unit 37 makes pwm unit 35 increase the duty ratio of pulse width modulating signals to pwm unit 35 output comparison control signals; And then the amplitude of increase output dc voltage, with stablizing of control output dc voltage amplitude.
In the utility model embodiment, parameters such as the efficient of AC-DC power conversion chip and reliability can reach the identical technical indicator of AC-DC power conversion chip with existing five pin SOT23 formulas encapsulation.
As the utility model one embodiment, AC-DC power conversion chip 3 can adopt the encapsulation of transistor T O92 (Transistor outline, transistor outline) formula.
In the utility model embodiment, utilize voltage regulation unit directly from the power pins receiving feedback signals, and directly detect the output low-voltage dc voltage from the direct current output pin through comparing unit; The pin of AC-DC power conversion chip is reduced to three; Effectively reduce cost of manufacture, and this structure is applicable to that the TO92 formula encapsulates, and has further simplified packaging technology; Reduce packaging cost, helped the extensive use of AC-DC power conversion chip.
Fig. 4 illustrates the structure of the power-switching circuit of the AC-DC power conversion chip that the utility model embodiment provides, and for the ease of explanation, only shows the part relevant with the utility model.
The power-switching circuit of this AC-DC power conversion chip can be used in charger, adapter, light fixture and the led drive circuit.
As the utility model one embodiment, the power-switching circuit of AC-DC power conversion chip comprises rectification circuit 41, filter capacitor C1, and said power-switching circuit also comprises:
When power supply electrifying, charge, to the start-up circuit 42 of chip 3 output starting resistors, the input of this start-up circuit 42 is connected with the end of filter capacitor C1, and the output of start-up circuit 42 is connected with the bringing-out of power pins 12;
Conducting when chip 3 output low-voltage dc voltages; The switching circuit 43 of output conducting electric current; The input of this switching circuit 43 is connected with the outside link of direct current output pin 33, the outside link common ground of the earth terminal of switching circuit 43 and grounding pin 31;
With the conducting current conversion is output voltage; And the transformer T1 of supply power voltage and feedback signal is provided for chip; The end of the same name of the elementary winding N1 of this transformer T1 is connected with the input of start-up circuit 42; The different name end of elementary winding N1 is connected with the output of switching circuit 43; The end of the same name of the secondary winding N2 of transformer T1 is the output negative pole of the power-switching circuit of AC-DC power conversion chip, and the different name end of the secondary winding N2 of transformer T1 is the output cathode of the power-switching circuit of AC-DC power conversion chip, the end ground connection of the same name of the auxiliary winding N3 of transformer T1;
Transmit the forward voltage in said supply power voltage and the feedback signal, resist the diode D6 of reverse voltage, the anode of diode D6 is connected with the different name end of the auxiliary winding N3 of transformer T1, and the negative electrode of diode D6 is connected with the bringing-out of power pins 32;
Reduce the filter circuit 46 of the ripple in the low pressure concussion direct voltage of sensing; The positive input terminal of filter circuit 46 is connected with the different name end of the secondary winding N2 of transformer T1; The negative input end of filter circuit 46 is connected with the end of the same name of the secondary winding N2 of transformer T1; The positive output end of filter circuit 46 is the output cathode of the power-switching circuit of AC-DC power conversion chip, and the negative output terminal of filter circuit 46 is the output negative pole of the power-switching circuit of AC-DC power conversion chip.
Be elaborated below in conjunction with the realization of specific embodiment to the utility model.
Fig. 5 illustrates the exemplary circuit structure of the power-switching circuit of the AC-DC power conversion chip that the utility model embodiment provides, and for the ease of explanation, only shows the part relevant with the utility model.
As the utility model one embodiment; Start-up circuit 42 comprises: resistance R 1 and capacitor C 3, and an end of resistance R 1 is the input of start-up circuit 42, the other end of resistance R 1 is connected with an end of capacitor C 3; Its link is the output of start-up circuit 42, the other end ground connection of capacitor C 3.
Switching circuit 43 comprises: triode Q1 and resistance R 3; The base stage of triode Q1 is the input of switching circuit 43; The current collection of triode Q1 is the output of switching circuit 43 very, and the emitter of triode Q1 is connected with an end of resistance R 3, and the other end of resistance R 3 is the earth terminal of switching circuit 43.
Filter circuit 46 comprises: diode D7, capacitor C 4 and resistance R 4; Capacitor C 4 is parallelly connected with resistance R 4; Capacitor C 4 is the negative input end and the negative output terminal of filter circuit 46 with a common port of resistance R 4 simultaneously; Capacitor C 4 is the positive output end of filter circuit 46 with another common port of resistance R 4, is connected with the negative electrode of diode D7, and the anode of diode D7 is the positive input terminal of filter circuit 46.
In the utility model embodiment; AC power through the high voltage direct current that becomes concussion behind the rectification circuit 41 that constitutes by rectifier bridge and the filter capacitor C1 through 3 chargings of 1 pair of capacitor C of resistance R; When the voltage on the capacitor C 3 reached the starting resistor 12V of chip 3, chip 3 was started working, and power pins 32 is the power supplies of chip 3 internal modules with the supply power voltage that this starting resistor converts chip internal into; And pass through direct current output pin 33 by pulse width modulation circuit 35 and export low-voltage dc voltages; This low-voltage dc voltage makes triode Q1 conducting, has the conducting electric current to flow through among the elementary winding N1 of triode Q1 and transformer T1, at this moment; The auxiliary winding N3 of transformer T1 provides externally fed voltage to make chip 3 continuous firings through diode D6 to chip 3 induced current; This externally fed voltage while inputs to voltage regulation unit 34 as feedback signal through power pins 32, and converting the galvanic current pressure into through voltage stabilizing circuit 34 is the chip internal power supply, and comparing unit 37 is gathered triode Q1 base stages through direct current output pin 33 voltage compares as sampled signal and reference voltage; With the stable low-voltage dc voltage of control impuls modulation circuit 35 outputs; This low-voltage dc voltage is sensed on the secondary winding N2 through the elementary winding N1 of transformer T1, because this voltage is coil-induced voltage, has certain ripple; Therefore the filter circuit 46 through diode D7 and capacitor C 4 and resistance R 4 compositions reduces ripple, exports stable low-voltage dc voltage.
In the utility model embodiment; Through changing AC-DC power conversion chip internal module structure and external power source change-over circuit; Make and only can realize that through power pins, grounding pin and direct current output pin alternating current arrives galvanic conversion, effectively reduce cost of manufacture, and this structure is applicable to the encapsulation of TO92 formula; Further simplify packaging technology, helped the extensive use of AC-DC power conversion chip.
As the utility model one embodiment, the power-switching circuit of AC-DC power conversion chip can also comprise:
Absorb the absorption circuit 45 of leakage inductance current spike voltage, the input that absorbs circuit 45 is connected with the different name end of the elementary winding N1 of transformer T1, and the output that absorbs circuit 45 is connected with the end of the same name of the elementary winding N1 of transformer T1.
This absorption circuit 45 comprises: diode D5, capacitor C 2 and resistance R 2; Resistance R 2 is parallelly connected with capacitor C 3; Resistance R 2 is the output that absorbs circuit 45 with a common port of capacitor C 3; Resistance R 2 is connected with the negative electrode of diode D5 with another common port of capacitor C 3, and the anode of diode D5 is for absorbing the input of circuit 45.
In the utility model embodiment, absorb the peak voltage that produces by the Transformer Winding leakage inductance through absorptive unit, it is breakdown that switch element is difficult for, and increased the reliability of the power-switching circuit of AC-DC power conversion chip.
In the utility model embodiment, utilize voltage regulation unit directly from the power pins receiving feedback signals, and directly detect the output low-voltage dc voltage from the direct current output pin through comparing unit; The pin of AC-DC power conversion chip is reduced to three; And, make and only can realize that through power pins, grounding pin and direct current output pin alternating current arrives galvanic conversion, effectively reduces cost of manufacture through its external power source change-over circuit of change; Simplified packaging technology; Help the extensive use of AC-DC power conversion chip, absorb peak voltage through increasing absorptive unit in addition, increased the reliability of the power-switching circuit of AC-DC power conversion chip.
The above is merely the preferred embodiment of the utility model; Not in order to restriction the utility model; Any modification of being done within all spirit and principles at the utility model, be equal to replacement and improvement etc., all should be included within the protection range of the utility model.

Claims (8)

1. an AC-DC power conversion chip comprises grounding pin, band-gap reference unit and pwm unit, it is characterized in that, said chip also comprises:
The power pins of input starting resistor or input chip exterior supply power voltage and feedback signal;
Export low-voltage dc voltage, and said low-voltage dc voltage is imported the direct current output pin of said chip as sampled signal;
Convert said starting resistor or chip exterior supply power voltage into the chip internal supply power voltage; And according to the voltage regulation unit of the amplitude of said feedback signal adjustment chip internal supply power voltage; The input of said voltage regulation unit is connected with the inside link of said power pins, and the output of said voltage regulation unit is connected with the input of said pwm unit;
The reference voltage that said sampled signal and said band-gap reference unit are provided relatively; Comparing unit to said pwm unit output comparison control signal; The first input end of said comparing unit is connected with the output of said band-gap reference unit; Second input of said comparing unit is connected with the inside link of said direct current output pin, and the output of said comparing unit is connected with the input of said pwm unit.
2. chip as claimed in claim 1 is characterized in that, said chip adopts the encapsulation of transistor T O-92 formula tripod.
3. a power-switching circuit that adopts chip as claimed in claim 1 comprises rectification circuit, filter capacitor C1, it is characterized in that said power-switching circuit also comprises:
When power supply electrifying, charge, to the start-up circuit of said chip output starting resistor, the input of said start-up circuit is connected with the end of said filter capacitor C1, and the output of said start-up circuit is connected with the bringing-out of said power pins;
Conducting when said chip is exported said low-voltage dc voltage; The switching circuit of output conducting electric current; The input of said switching circuit is connected with the outside link of said direct current output pin, the outside link common ground of the earth terminal of said switching circuit and said grounding pin;
With said conducting current conversion is output voltage; And be the transformer T1 that said chip provides said supply power voltage and feedback signal; The end of the same name of the elementary winding N1 of said transformer T1 is connected with the input of said start-up circuit; The different name end of said elementary winding N1 is connected with the output of said switching circuit; The end of the same name of the secondary winding N2 of said transformer T1 is the output negative pole of said power-switching circuit, and the different name end of the secondary winding N2 of said transformer T1 is the output cathode of said power-switching circuit, the end ground connection of the same name of the auxiliary winding N3 of said transformer T1;
Transmit the forward voltage in said supply power voltage and the feedback signal; Resist the diode D6 of reverse voltage; The anode of said diode D6 is connected with the different name end of the auxiliary winding N3 of said transformer T1, and the negative electrode of said diode D6 is connected with the bringing-out of said power pins;
Reduce the filter circuit of the ripple in the low-voltage dc voltage of sensing; The positive input terminal of said filter circuit is connected with the different name end of the secondary winding N2 of said transformer T1; The negative input end of said filter circuit is connected with the end of the same name of the secondary winding N2 of said transformer T1; The positive output end of said filter circuit is the output cathode of said power-switching circuit, and the negative output terminal of said filter circuit is the output negative pole of said power-switching circuit.
4. power-switching circuit as claimed in claim 3 is characterized in that, said start-up circuit comprises:
Resistance R 1 and capacitor C 3;
One end of said resistance R 1 is the input of said start-up circuit, and the other end of said resistance R 1 is connected with an end of said capacitor C 3, and its link is the output of said start-up circuit, the other end ground connection of said capacitor C 3.
5. power-switching circuit as claimed in claim 3 is characterized in that, said switching circuit comprises:
Triode Q1 and resistance R 3;
The base stage of said triode Q1 is the input of said switching circuit; The output of the very said switching circuit of the current collection of said triode Q1; The emitter of said triode Q1 is connected with an end of said resistance R 3, and the other end of said resistance R 3 is the earth terminal of said switching circuit.
6. power-switching circuit as claimed in claim 3 is characterized in that, said filter circuit comprises:
Diode D7, capacitor C 4 and resistance R 4;
Said capacitor C 4 is parallelly connected with said resistance R 4; Said capacitor C 4 is the negative input end and the negative output terminal of said filter circuit with a common port of said resistance R 4 simultaneously; Said capacitor C 4 is the positive output end of said filter circuit with another common port of said resistance R 4; Be connected with the negative electrode of said diode D7, the anode of said diode D7 is the positive input terminal of said filter circuit.
7. power-switching circuit as claimed in claim 3 is characterized in that, said power-switching circuit also comprises:
Absorb the absorption circuit of leakage inductance current spike voltage, the input of said absorption circuit is connected with the different name end of the elementary winding N1 of said transformer T1, and the output of said absorption circuit is connected with the end of the same name of the elementary winding N1 of said transformer T1.
8. power-switching circuit as claimed in claim 7 is characterized in that, said absorption circuit comprises:
Utmost point pipe D5, capacitor C 2 and resistance R 2;
Said resistance R 2 is parallelly connected with said capacitor C 3; Said resistance R 2 is the output of said absorption circuit with a common port of said capacitor C 3; Said resistance R 2 is connected with the negative electrode of said diode D5 with another common port of said capacitor C 3, and the anode of said diode D5 is the input of said absorption circuit.
CN2011202802598U 2011-08-03 2011-08-03 AC-DC power conversion chip and power conversion circuit Expired - Lifetime CN202178715U (en)

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CN102263515A (en) * 2011-03-31 2011-11-30 深圳市富满电子有限公司南山分公司 AC-DC (alternating current-direct current) power conversion chip and power conversion circuit
CN105356171A (en) * 2015-11-18 2016-02-24 中国南方电网有限责任公司电网技术研究中心 Wall-in type intelligent socket
CN108427028A (en) * 2017-02-13 2018-08-21 三星电子株式会社 A kind of semiconductor devices for monitoring backward voltage

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102263515A (en) * 2011-03-31 2011-11-30 深圳市富满电子有限公司南山分公司 AC-DC (alternating current-direct current) power conversion chip and power conversion circuit
CN105356171A (en) * 2015-11-18 2016-02-24 中国南方电网有限责任公司电网技术研究中心 Wall-in type intelligent socket
CN108427028A (en) * 2017-02-13 2018-08-21 三星电子株式会社 A kind of semiconductor devices for monitoring backward voltage
CN108427028B (en) * 2017-02-13 2022-06-07 三星电子株式会社 Semiconductor device for monitoring reverse voltage

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