CN101714817A - Voltage converter with line loss compensation - Google Patents

Abstract

The invention discloses a voltage converter with line loss compensation, which comprises a control circuit and a line loss compensation module. Input voltage Vin is input into the control circuit; the control circuit performs voltage conversion; after the output circuit of the control circuit passes through a filtering circuit, the control circuit outputs a converted voltage VOUT; after the converted voltage VOUT passes through a conducting wire, the voltage becomes an after wire output voltage Vo; the after wire output voltage Vo is supplied to load; voltage drop is produced between the converted voltage VOUT and the after wire output voltage Vo because of the parasitic resistance Rline of the conducting wire; the line loss compensation module samples the voltage drop produced between the converted voltage VOUT and the after wire output voltage Vo and feeds back the voltage drop to the control circuit, therefore, the after wire output voltage Vo reaches the set value. The voltage converter has the advantages that the line is simple to be realized, when the voltage converter is applied to a vehicle charger, constant voltage/constant current control can be realized, and input and output ports of circuits and external components are not required to be added.

Description

The electric pressure converter of band line loss compensation

Technical field

The present invention relates to the line loss compensation technique of output voltage in the voltage transitions, relate in particular to the line loss compensation technique of onboard charger output voltage.

Background technology

Electric pressure converter as shown in Figure 1 (1) needs the output constant voltage, output voltage through the first divider resistance R1, the second divider resistance R2 dividing potential drop after, electric pressure converter (1) control FB port voltage value equals electric pressure converter (1) internal reference magnitude of voltage and realizes.Yet electric pressure converter (1) is when powering to load, often because connection electric pressure converter (1) is long with the lead of load, the dead resistance of lead is Rline, the dead resistance Rline that load current flows through lead produces pressure drop, the voltage that finally causes electric pressure converter (1) to provide to load is lower than the output voltage of setting, influences the operate as normal of load.

The demand of electric pressure converter output constant voltage is particularly evident in onboard charger, and onboard charger often requires constant current/constant voltage (CC/CV) control, and promptly when output current during less than cut-off current, output voltage stabilization is in set point; When output current reached cut-off current, outputting current steadily was at cut-off current, and output voltage begins to descend.The CC/CV characteristic curve of onboard charger as shown in Figure 2.

Onboard charger is generally realized by the electric pressure converter of band constant current control at present.Fig. 3 is the electric pressure converter block diagram, comprises current sample module (10), current error amplification module (11), voltage error amplification module (12), PWM control module (13), driving and switch module (14), wherein:

Described current sample module (10) comprises voltage operational amplifier A1, and the positive input terminal of A1 is as the CS+ port of electric pressure converter, and the negative input end of A1 is as the CS-port of electric pressure converter;

Described current error amplification module (11) comprises current error amplifier A2, the positive input termination second reference voltage V REF2 of current error amplifier A2, and the negative input end of current error amplifier A2 connects the output of voltage operational amplifier A1;

Described voltage error amplification module (12) comprises voltage error amplifier A3, the positive input termination internal reference voltage VREF of voltage error amplifier A3, and the negative input of voltage error amplifier A3 is as the FB port of electric pressure converter;

The input of described PWM control module (13) connects the output of current error amplifier A2 and the output of voltage error amplifier A3;

Described driving and switch module (14) comprise power switch pipe PMOS M1 and drive circuit A4, the input of drive circuit A4 is connected to the output of PWM control module, the output of drive circuit A4 connects the grid of power switch pipe PMOS M1, the source electrode of power switch pipe PMOS M1 is as the Vin port of electric pressure converter, and the drain electrode of power switch pipe PMOS M1 is as the SW port of electric pressure converter.

Onboard charger connects and composes the onboard charger system in when work with filter circuit and external circuit as shown in Figure 3, its system configuration as shown in Figure 4:

Described filter circuit and external circuit comprise inductance L 1, sampling resistor Rsense, sustained diode 1, output capacitance C1, feedback divider resistance R1 and R2, dead resistance Rline and load; Described inductance L 1 is connected across the SW port and the CS+ port of electric pressure converter; Described sampling resistor Rsense is connected across the CS+ port and the CS-port of electric pressure converter; Described sustained diode 1 positive pole is connected to ground, and negative pole is connected to the SW port of electric pressure converter: described output capacitance C1 one end is connected to ground, and the other end is connected to the CS+ port of electric pressure converter; Described dead resistance Rline one end is connected to the CS-port of electric pressure converter, and the other end is connected to load, and flow through sampling resistor Rsense but the voltage of the dead resistance Rline that do not flow through as yet are called output voltage before the line, are designated as V ' _O, after the dead resistance of the flowing through Rline voltage be called output voltage behind the line, be designated as Vo.

The operation principle of onboard charger system shown in Figure 4 is:

After system initially powers on, set up internal reference voltage VREF and VREF2; When load current during less than the output current cut-off current set, after outside output voltage V o process divider resistance R1, the R2 dividing potential drop, the FB port of input voltage transducer, voltage error amplification module (12) amplifies the pressure reduction between FB port voltage and the reference voltage V REF, PWM control module (13) is according to the output of voltage error amplification module (12), control switch M1 opens and ends, and the storage by inductance L 1 and releasing energy is to capacitor C 1 charging; Finally the positive input terminal VREF voltage of voltage error amplification module (12) equates with negative input end FB port voltage, at this moment, and voltage V ' before the line _OFor

Voltage Vo is behind the line $\mathrm{VREF}\&CenterDot;\frac{\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="H2009101552751E00032.png,H2009101552751E00042.png"\; state="\{\{state\}\}">R</figure-callout>}1+R2}{R2}-\mathrm{Io}\&CenterDot;\mathrm{Rline}.$

By voltage equation behind the line as seen, voltage changes with load current value behind the line of current onboard charger system, because the CS+ port of electric pressure converter and the output of CS-port are connected a charge power supply line, there is certain resistance in this charge power supply line, output current this charge power supply line of flowing through, can produce corresponding pressure drop, output voltage is lower than set point after causing the line of onboard charger, there is error, and output current is big more, charging wire resistance is big more, and the error of output voltage is big more, the operate as normal of influence back level load.

Summary of the invention

The present invention will solve the deficiencies in the prior art, and a kind of electric pressure converter with the line loss compensation is provided.

The present invention simultaneously also will be applied to onboard charger with the electric pressure converter of line loss compensation.

The electric pressure converter of band line loss compensation, comprise control circuit and line loss compensating module: input voltage vin is imported described control circuit, control circuit carries out voltage transitions to input voltage vin, changing voltage VOUT is exported in the output of control circuit behind filter circuit, changing voltage VOUT is output voltage V o behind the line through the voltage behind the lead, output voltage V o offers load behind the line, because the dead resistance Rline of lead itself, cause producing pressure drop between the output voltage V o behind changing voltage VOUT and the line; The pressure drop that produces between the output voltage V o behind described line loss compensating module sample conversion voltage VOUT and the line also feeds back to control circuit, thereby output voltage V o reaches set point after making line.

Further the electric pressure converter of band line loss compensation connects with peripheral circuit, described peripheral circuit comprises lead, the first divider resistance R1, the second divider resistance R2, sampling resistor Rsense, described control circuit connects the lead and the first divider resistance R1 through filter circuit, the other end of lead is connected to load, changing voltage VOUT powers to the load through lead and forms the output current path, the other end of the first divider resistance R1, the second divider resistance R2 that connects, and by the second divider resistance R2 ground connection, series connection one sampling resistor Rsense in the output current path that output current Io flows through, two inputs of described line loss compensating module are connected the electric current of the two ends of the electric positive Rsnse of sampling with sampling output current path, the output output negative current of line loss compensating module, the output of line loss compensating module is connected to the tie point of the second divider resistance R2 with the first divider resistance R1 through the FB port of the electric pressure converter of band line loss compensation, the described negative current first divider resistance R1 that flows through, the FB port voltage is reduced, by the adjusting of control circuit, thereby output voltage V o reaches set point after making line.

Described line loss compensating module is trsanscondutor A5, and the pass between the parasitic electric positive Rline of the first divider resistance R1 and sampling resistor Rsense, lead and the trsanscondutor A5 of line loss compensating module is: $\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="H2009101552751E00032.png,H2009101552751E00042.png"\; state="\{\{state\}\}">R</figure-callout>}1=\frac{\mathrm{Rline}}{\mathrm{Rsense}\&CenterDot;\mathrm{Gm}},$ Wherein Gm is the transconductance value of trsanscondutor A5.

Described compensating module and control circuit are integrated in same chip.

The electric pressure converter of above-mentioned band line loss compensation is applied to onboard charger, and wherein, described control circuit comprises voltage error amplification module, PWM control module, driving and switch module:

The anode of described voltage error amplification module is imported the first reference voltage V REF, and negative terminal connects described FB port, and the voltage error amplification module amplifies the error between the FB port voltage and the first reference voltage V REF;

The output of described voltage error amplification module connects the input of PWM control module, PWM control module output switching drive signal;

Described driving and switch module comprise drive circuit A4 and power switch pipe M1, described switching drive signal input driving circuit A4, the output of drive circuit A4 connects the control end of power switch pipe M1, first output of power switch pipe M1 and second output are respectively as the Vin port and the SW port of control circuit, drive circuit A4 is according to the switching drive signal of PWM control module output, and power controlling switching tube M1 opens and ends;

The negative input end of described line loss compensating module is as the CS+ port, and positive input terminal is as the CS-port.

Described filter circuit comprises inductance L 1, sustained diode 1, output capacitance C1, and described inductance L 1 one ends connect the SW port, and the other end connects electric capacity, the other end ground connection of electric capacity, and sustained diode 1 plus earth, negative pole connects the SW port.

Described voltage error amplification module comprises the first error amplifier A3, the positive input termination first reference voltage V REF of the first error amplifier A3, and the negative input of the first voltage error amplifier A3 connects the FB port.

Described PWM control module comprises comparator A7 and oscillator A8, the triangular signal of described oscillator A8 output fixed frequency, the positive input terminal of described comparator A7 is as the input of PWM control module, the triangular wave output signal of the negative input end input oscillator module A8 of comparator A7, the output of comparator A7 is the output of PWM control module.When the input of PWM control module during greater than the triangular signal of A8 output, the PWM module is output as high level, by switch drive module power controlling switch M1 conducting; When the input of PWM control module during less than the triangular signal of oscillator A8 output, the PWM module is output as low level, and M1 ends by switch drive module power controlling switch.

When the electric pressure converter of described band line loss compensation was used for onboard charger, described control circuit also comprised current sample module and current error amplification module:

The positive input terminal of described current sample module connects the CS+ port, negative input end connects the CS-port, pressure reduction between current sample module samples CS+ port and the CS-port, flowing through by the reflection of this voltage difference is connected across the output current of the sampling resistor Rsense between CS+ port and the CS-port;

The positive input terminal of described current error amplification module is imported the second reference voltage V REF2, negative terminal connects the output of current sample module, error between the current error amplification module amplified current sampling module output voltage and the second reference voltage V REF2, the output of current error amplification module connects the input of PWM control module.

Further, described current sample module comprises that the positive input terminal of second operational amplifier A, 1, the second operational amplifier A 1 connects the CS+ port, and negative input end connects the CS-port;

Described current error amplification module comprises the 3rd error amplifier A2, and the positive input terminal of the 3rd error amplifier A2 is imported the second reference voltage V REF2, and negative input end connects the output of second operational amplifier A 1.

Current error amplification module and voltage error amplification module can be merged into a voltage error amplification module, and described voltage error amplification module has two negative input ends, connect the output of current sample module and line loss compensating module respectively.

Described voltage error amplification module, PWM control module, drive circuit A4 and line loss compensating module are integrated in a chip, all right further integrated power switching tube M1, current sample module and current error amplification module in this chip.

The line loss compensating module is a trsanscondutor, and the pass of the output current of described trsanscondutor and trsanscondutor input voltage is:

I ₁＝(V ₁₊-V _1-)Gm，

Wherein, I ₁Be the output current of trsanscondutor, V _1-Be negative input end voltage, V ₁₊Be positive input terminal voltage.

The invention has the beneficial effects as follows: the electric pressure converter that the invention provides the compensation of band line loss has overcome because the dead resistance Rline of lead itself by introducing the line loss compensating module, cause producing pressure drop between the output voltage V o behind changing voltage VOUT and the line, thereby output voltage V o reaches set point after making line, greatly reduced the variation of output voltage under the different loads electric current, the present invention simultaneously realizes simply, only need promptly can realize the line loss compensation according to the mutual conductance of line loss compensating module and the lead dead resistance resistance of onboard charger; When the present invention is applied to onboard charger, can realize reaching constant voltage/constant current control, compare with traditional onboard charger simultaneously, line loss compensating module and the shared same port of current sample module can not needed to increase the input/output port and the external component of circuit.

Description of drawings:

Fig. 1 be the conventional voltage transducer and with the connection diagram of load

Fig. 2 is the CC/CV performance diagram of traditional vehicle-mounted charger circuit output

Fig. 3 is conventional voltage converter structure figure

Fig. 4 is the onboard charger system block diagram that the electric pressure converter of tradition band constant current control is realized

Fig. 5 is the electric pressure converter structure chart of band line loss compensation of the present invention

Fig. 6 is applied to the structure chart of onboard charger for the electric pressure converter of band line loss compensation of the present invention

Fig. 7 is applied to the structure chart of onboard charger for the electric pressure converter of band line loss compensation of the present invention

Fig. 8 is applied to the structure chart of onboard charger for the electric pressure converter of band line loss compensation of the present invention

Fig. 9 is the PWM control module structure chart in the onboard charger of the present invention

Figure 10 is a line loss compensating module circuit diagram of the present invention

Figure 11 is a line loss compensating module circuit diagram of the present invention

Figure 12 is the change curve of the output voltage of the onboard charger before and after the increase line loss compensating module to output current

Embodiment

Below in conjunction with accompanying drawing content of the present invention is further specified.

The electric pressure converter of band line loss compensation, comprise control circuit (31) and line loss compensating module (32): input voltage vin is imported described control circuit (31), control circuit (31) carries out voltage transitions to input voltage vin, changing voltage VOUT is exported in the output of control circuit (31) behind filter circuit (33), changing voltage VOUT is output voltage V o behind the line through the voltage behind the lead, output voltage V o offers load behind the line, because the dead resistance Rline of lead itself, cause producing pressure drop between the output voltage V o behind changing voltage VOUT and the line; The pressure drop that produces between the output voltage V o behind described line loss compensating module (32) sample conversion voltage VOUT and the line also feeds back to control circuit (31), thereby output voltage V o reaches set point after making line.

Further the electric pressure converter of band line loss compensation is with the connection of peripheral circuit, described peripheral circuit comprises lead, the first divider resistance R1, the second divider resistance R2, sampling resistor Rsense, described control circuit (31) connects the lead and the first divider resistance R1 through filter circuit (33), the other end of lead is connected to load, changing voltage VOUT powers to the load through lead and forms the output current path, the other end of the first divider resistance R1, the second divider resistance R2 that connects, and by the second divider resistance R2 ground connection, series connection one sampling resistor Rsense in the output current path that output current Io flows through, two inputs of line loss compensating module (32) are connected the electric current of the two ends of sampling resistor Rsense with sampling output current path, the output output negative current of line loss compensating module (32), the output of line loss compensating module (32) is connected to the tie point of the second divider resistance R2 with the first divider resistance R1 through the FB port of the electric pressure converter of band line loss compensation, the described negative current first divider resistance R1 that flows through, the FB port voltage is reduced, by the adjusting of control circuit (31), thereby output voltage V o reaches set point after making line.

Described line loss compensating module (32) is trsanscondutor A5, and the pass between the parasitic electric positive Rline of the first divider resistance R1 and sampling resistor Rsense, lead and the trsanscondutor A5 of line loss compensating module (32) is: $\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="H2009101552751E00032.png,H2009101552751E00042.png"\; state="\{\{state\}\}">R</figure-callout>}1=\frac{\mathrm{Rline}}{\mathrm{Rsense}\&CenterDot;\mathrm{Gm}},$ Wherein Gm is the transconductance value of trsanscondutor A5.

Described compensating module (32) is integrated in same chip with control circuit (31).

Be that example explanation is as mentioned above below with Fig. 5 with the realization principle of the electric pressure converter of line loss compensation:

As shown in Figure 5, the voltage between sampling resistor Rsense and the lead is output voltage before the line, is designated as V ' _O, its set point is:

$V_{\mathrm{OSET}}=\frac{R1+R2}{R2}\mathrm{VREF};---\left(1\right)$

VREF is first reference voltage of control circuit (31) inner setting, control circuit (31) powers to the load through filter circuit, sampling resistor Rsense, lead, the electric current I o sampling resistor Rsense that flows through, the pressure drop that produces at sampling resistor Rsense two ends, line loss compensating module (32) output negative current also passes through the FB port flow through the first divider resistance R1, make the voltage of FB port descend, by the adjusting of control circuit (31), output voltage V before the line ' _ORise, the part voltage compensation of rising specifically is calculated as follows because of the flow through line loss of the output voltage that lead produces of output current:

The pressure drop at sampling resistor Rsense two ends is IoRsense, and wherein Io is a load current;

The negative current of line loss compensating module (32) output is: IoRsenseGm;

This electric current first divider resistance R1 that flows through, then the voltage of FB port becomes:

$V_{\mathrm{FB}}=V_O^{,}\&CenterDot;\frac{R2}{\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="H2009101552751E00032.png,H2009101552751E00042.png"\; state="\{\{state\}\}">R</figure-callout>}1+R2}-\mathrm{Io}\&CenterDot;\mathrm{Rsense}\&CenterDot;\mathrm{Gm}\&CenterDot;\frac{\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="H2009101552751E00032.png,H2009101552751E00042.png"\; state="\{\{state\}\}">R</figure-callout>}1\&CenterDot;R2}{\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="H2009101552751E00032.png,H2009101552751E00042.png"\; state="\{\{state\}\}">R</figure-callout>}1+R2}---\left(2\right)$

The voltage of setting the FB port equals the first reference voltage VREF, then

$\mathrm{VREF}=V_O^{\&prime;}\&CenterDot;\frac{R2}{\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="H2009101552751E00032.png,H2009101552751E00042.png"\; state="\{\{state\}\}">R</figure-callout>}1+R2}-\mathrm{Io}\&CenterDot;\mathrm{Rsense}\&CenterDot;\mathrm{Gm}\&CenterDot;\frac{\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="H2009101552751E00032.png,H2009101552751E00042.png"\; state="\{\{state\}\}">R</figure-callout>}1\&CenterDot;R2}{\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="H2009101552751E00032.png,H2009101552751E00042.png"\; state="\{\{state\}\}">R</figure-callout>}1+R2}---\left(3\right)$

Then, $V_O^{\&prime;}=\frac{\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="H2009101552751E00032.png,H2009101552751E00042.png"\; state="\{\{state\}\}">R</figure-callout>}1+R2}{R2}(\mathrm{VREF}+\mathrm{Io}\&CenterDot;\mathrm{Rsense}\&CenterDot;\mathrm{Gm}\&CenterDot;\frac{\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="H2009101552751E00032.png,H2009101552751E00042.png"\; state="\{\{state\}\}">R</figure-callout>}1\&CenterDot;R2}{\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="H2009101552751E00032.png,H2009101552751E00042.png"\; state="\{\{state\}\}">R</figure-callout>}1+R2})---\left(4\right)$

$=\frac{\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="H2009101552751E00032.png,H2009101552751E00042.png"\; state="\{\{state\}\}">R</figure-callout>}1+R2}{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="H2009101552751E00031.png"\; state="\{\{state\}\}">R</figure-callout>}2}\mathrm{VREF}+\mathrm{Io}\&CenterDot;\mathrm{Rsense}\&CenterDot;\mathrm{Gm}\&CenterDot;R1---\left(5\right)$

Through output voltage: Vo=V ' behind the line of lead _O-IoRline (6)

In (4) formula substitution (6) formula, obtain:

$\mathrm{Vo}=\frac{\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="H2009101552751E00032.png,H2009101552751E00042.png"\; state="\{\{state\}\}">R</figure-callout>}1+R2}{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="H2009101552751E00031.png"\; state="\{\{state\}\}">R</figure-callout>}2}\mathrm{VREF}+\mathrm{Io}\&CenterDot;\mathrm{Rsense}\&CenterDot;\mathrm{Gm}\&CenterDot;R1-\mathrm{Io}\&CenterDot;\mathrm{Rline}---\left(7\right)$

$=\frac{\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="H2009101552751E00032.png,H2009101552751E00042.png"\; state="\{\{state\}\}">R</figure-callout>}1+R2}{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="H2009101552751E00031.png"\; state="\{\{state\}\}">R</figure-callout>}2}\mathrm{VREF}+\mathrm{Io}\&CenterDot;(\mathrm{Rsense}\&CenterDot;\mathrm{Gm}\&CenterDot;R1-\mathrm{Rline})---\left(8\right)$

With rated output voltage $V_{\mathrm{OSET}}=\frac{\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="H2009101552751E00032.png,H2009101552751E00042.png"\; state="\{\{state\}\}">R</figure-callout>}1+R2}{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="H2009101552751E00031.png"\; state="\{\{state\}\}">R</figure-callout>}2}\mathrm{VREF}$ Difference be:

V _O-V _OSET＝Io·(Rsense·Gm·R1-Rline) (9)

Make both differences minimum and irrelevant, then with output current

Rsense·Gm·R1-Rline＝0 (10)

That is, $\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="H2009101552751E00032.png,H2009101552751E00042.png"\; state="\{\{state\}\}">R</figure-callout>}1=\frac{\mathrm{Rline}}{\mathrm{Rsense}\&CenterDot;\mathrm{Gm}}---\left(11\right)$

Wherein, the transconductance value Gm of trsanscondutor determines that the Rsense value determines that according to the output current limiting value dead resistance Rline is relevant with length, the model (resistivity) of charge power supply line.Therefore, as long as the first divider resistance R1 satisfies (11) formula, promptly can reach the effect of line loss compensation.

The electric pressure converter of above-mentioned band line loss compensation is applied to onboard charger, and as shown in Figure 6, wherein, described control circuit (31) comprises voltage error amplification module (312), PWM control module (313), driving and switch module (314):

The anode of described voltage error amplification module (312) is imported the first reference voltage V REF, and negative terminal connects described FB port, and voltage error amplification module (312) amplifies the error between the FB port voltage and the first reference voltage V REF;

The output of described voltage error amplification module (312) connects the input of PWM control module (313), PWM control module (313) output switching drive signal;

Described driving and switch module (314) comprise drive circuit A4 and power switch pipe M1, described switching drive signal input driving circuit A4, the output of drive circuit A4 connects the control end of power switch pipe M1, first output of power switch pipe M1 and second output are respectively as the Vin port and the SW port of control circuit (31), drive circuit A4 is according to the switching drive signal of PWM control module (313) output, and power controlling switching tube M1 opens and ends;

The negative input end of described line loss compensating module (32) is as the CS+ port, and positive input terminal is as the CS-port.

Described filter circuit comprises inductance L 1, sustained diode 1, output capacitance C1, and described inductance L 1-end connects the SW port, and the other end connects electric capacity, the other end ground connection of electric capacity, and sustained diode 1 plus earth, negative pole connects the SW port.

Described voltage error amplification module (312) comprises the first error amplifier A3, the positive input termination first reference voltage V REF of the first error amplifier A3, and the negative input of the first voltage error amplifier A3 connects the FB port.

Described PWM control module (313) comprises comparator A7 and oscillator A8, the triangular signal of described oscillator A8 output fixed frequency, the positive input terminal of described comparator A7 is as the input of PWM control module, the triangular wave output signal of the negative input end input oscillator module A8 of comparator A7, the output of comparator A7 is the output of PWM control module.When the input of PWM control module during greater than the triangular signal of A8 output, the PWM module is output as high level, by switch drive module power controlling switch M1 conducting; When the input of PWM control module during less than the triangular signal of oscillator A8 output, the PWM module is output as low level, and M1 ends by switch drive module power controlling switch.

The power switch pipe M1 of described switching tube and driver module thereof (314) is the PMOS pipe, and the source electrode of power switch pipe M1 is as the Vin port of electric pressure converter, and the drain electrode of power switch pipe M1 is as the SW port of electric pressure converter; Described power switch pipe M1 also can be positive-negative-positive triode, N channel enhancement metal-oxide-semiconductor or NPN type triode, if M1 is N channel enhancement metal-oxide-semiconductor or NPN type triode, driver module A4 generally adopts bootstrap approach.

As shown in Figure 7, when the electric pressure converter of described band line loss compensation was used for onboard charger, described control circuit (31) also comprised current sample module (310) and current error amplification module (311):

The positive input terminal of described current sample module (310) connects the CS+ port, negative input end connects the CS-port, pressure reduction between current sample module samples CS+ port and the CS-port, flowing through by the reflection of this voltage difference is connected across the output current of the sampling resistor Rsense between CS+ port and the CS-port;

The positive input terminal of described current error amplification module (311) is imported the second reference voltage V REF2, negative terminal connects the output of current sample module (310), error between current error amplification module (311) the amplified current sampling module output voltage and the second reference voltage V REF2, the output of current error amplification module connects the input of PWM control module.

Further, described current sample module (310) comprises that the positive input terminal of second operational amplifier A, 1, the second operational amplifier A 1 connects the CS+ port, and negative input end connects the CS-port;

Described current error amplification module (311) comprises the 3rd error amplifier A2, and the positive input terminal of the 3rd error amplifier A2 is imported the second reference voltage V REF2, and negative input end connects the output of second operational amplifier A 1.

As shown in Figure 8, current error amplification module (311) and voltage error amplification module (312) can be merged into a voltage error amplification module, described voltage error amplification module has two negative input ends, connects the output of current sample module (310) and line loss compensating module (3) respectively.

Described voltage error amplification module, PWM control module, drive circuit A4 and line loss compensating module are integrated in a chip, all right further integrated power switching tube M1, current sample module and current error amplification module in this chip.

Fig. 5,6,7,8 line loss compensating module (32) are trsanscondutor, and shown in Figure 10,11, the pass of the output current of described trsanscondutor and trsanscondutor input voltage is: I ₁=(V ₁₊-V _1-) Gm, wherein, I ₁Be the output current of trsanscondutor, V _1-Be negative input end voltage, V ₁₊Be positive input terminal voltage.

Trsanscondutor as shown in figure 10 comprises the 5th resistance R 5, the 6th resistance R 6, the four error amplifier A8, metal-oxide-semiconductor M10, metal-oxide-semiconductor M11, metal-oxide-semiconductor M12; One end of the 5th resistance R 5 is as the positive input terminal V of trsanscondutor ₁₊, the other end is linked the positive input terminal of the 4th error amplifier A8, and an end of the 6th resistance R 6 is as the negative input end V of trsanscondutor _1-, the other end is linked the negative input end of error amplifier A8, and the grid of metal-oxide-semiconductor M10 is linked in the output of error amplifier A8, and the source electrode of metal-oxide-semiconductor M10 is linked the positive input terminal of error amplifier A8, and the drain electrode of M11 is linked in the drain electrode of M10; The grid of M11, M12 is all linked the drain electrode of M11, and the source electrode of M11, M12 is all linked ground; The source electrode of M12 is as trsanscondutor output I ₁

Wherein, described metal-oxide-semiconductor M10 is the P-channel enhancement type metal-oxide-semiconductor, and described metal-oxide-semiconductor M11, M12 are N channel enhancement metal-oxide-semiconductor;

Wherein, described metal-oxide-semiconductor M10 can replace with the PNP triode, and described metal-oxide-semiconductor M11, M12 can replace with the NPN triode, and its corresponding connected mode in like manner;

Similarly, described trsanscondutor module also can be as shown in figure 11, and described metal-oxide-semiconductor M13 is a N channel enhancement metal-oxide-semiconductor simultaneously, and described metal-oxide-semiconductor M14, M15 are N channel enhancement metal-oxide-semiconductor; Described metal-oxide-semiconductor M13 can replace with the NPN triode, and described metal-oxide-semiconductor M14, M15 can replace with the NPN triode, and its corresponding connected mode in like manner.

Described line loss compensating module also can be realized with the trsanscondutor of other structure.

Figure 12 increases before and after the line loss compensating module, and output voltage is to the simulation result contrast of the variation of output current.

The invention discloses the electric pressure converter of band line loss compensation and the application in onboard charger thereof, and describe the specific embodiment of the present invention and effect with reference to the accompanying drawings.What should be understood that is: the foregoing description is just to explanation of the present invention; rather than limitation of the present invention; any innovation and creation that do not exceed in the connotation scope of the present invention; include but not limited to the compensating module circuit modification, to the change of the local structure of circuit (as utilize those skilled in the art thinkable technical method replace trsanscondutor among the present invention etc.), to the replacement of the type or the model of components and parts; and the replacement of other unsubstantialities or modification, all fall within the protection range of the present invention.

Claims (15)

1. be with the electric pressure converter of line loss compensation, it is characterized in that comprising control circuit and line loss compensating module: input voltage vin is imported described control circuit, control circuit carries out voltage transitions to input voltage vin, changing voltage VOUT is exported in the output of control circuit behind filter circuit, changing voltage VOUT is output voltage V o behind the line through the voltage behind the lead, output voltage V o offers load behind the line, because the dead resistance Rline of lead itself, cause producing pressure drop between the output voltage V o behind changing voltage VOUT and the line; The pressure drop that produces between the output voltage V o behind described line loss compensating module sample conversion voltage VOUT and the line also feeds back to control circuit, thereby output voltage V o reaches set point after making line.

2. the electric pressure converter of band line loss compensation as claimed in claim 1, it is characterized in that connecting with peripheral circuit with the electric pressure converter of line loss compensation, described peripheral circuit comprises lead, the first divider resistance R1, the second divider resistance R2, sampling resistor Rsense, described control circuit connects the lead and the first divider resistance R1 through filter circuit, the other end of lead is connected to load, changing voltage VOUT powers to the load through lead and forms the output current path, the other end of the first divider resistance R1, the second divider resistance R2 that connects, and by the second divider resistance R2 ground connection, series connection one sampling resistor Rsense in the output current path that output current Io flows through, two inputs of described line loss compensating module are connected the electric current of the two ends of sampling resistor Rsense with sampling output current path, the output output negative current of line loss compensating module, the output of line loss compensating module is connected to the tie point of the second divider resistance R2 with the first divider resistance R1 through the FB port of the electric pressure converter of band line loss compensation, the described negative current first divider resistance R1 that flows through, the FB port voltage is reduced, by the adjusting of control circuit, thereby output voltage V o reaches set point after making line.

3. the electric pressure converter of band line loss compensation as claimed in claim 2, it is characterized in that described line loss compensating module is trsanscondutor A5, the pass between the dead resistance Rline of the first divider resistance R1 and sampling resistor Rsense, lead and the trsanscondutor A5 of line loss compensating module is: $R1=\frac{\mathrm{Rline}}{\mathrm{Rsense}\&CenterDot;\mathrm{Gm}},$ Wherein Gm is the transconductance value of trsanscondutor A5.

4. as the electric pressure converter of claim 1,2 or 3 described band line loss compensation, it is characterized in that described compensating module and control circuit are integrated in same chip.

5. as the electric pressure converter of claim 1, the compensation of 2 or 3 described band line losses, when it is characterized in that electric pressure converter with the compensation of described band line loss is applied to onboard charger, described control circuit comprises voltage error amplification module, PWM control module, driving and switch module:

The anode of described voltage error amplification module is imported the first reference voltage V REF, and negative terminal connects described FB port, and the voltage error amplification module amplifies the error between the FB port voltage and the first reference voltage V REF;

The output of described voltage error amplification module connects the input of PWM control module, PWM control module output switching drive signal;

Described driving and switch module comprise drive circuit A4 and power switch pipe M1, described switching drive signal input driving circuit A4, the output of drive circuit A4 connects the control end of power switch pipe M1, first output of power switch pipe M1 and second output are respectively as the Vin port and the SW port of control circuit, drive circuit A4 is according to the switching drive signal of PWM control module (23) output, and power controlling switching tube M1 opens and ends;

The negative input end of described line loss compensating module is as the CS+ port, and positive input terminal is as the CS-port.

6. the electric pressure converter of band line loss compensation as claimed in claim 5, it is characterized in that described voltage error amplification module comprises the first error amplifier A3, the positive input termination first reference voltage V REF of the first error amplifier A3, the negative input of the first voltage error amplifier A3 connects the FB port.

7. the electric pressure converter of band line loss compensation as claimed in claim 5, it is characterized in that described PWM control module comprises comparator A7 and oscillator A8, the triangular signal of described oscillator A8 output fixed frequency, the positive input terminal of described comparator A7 is as the input of PWM control module, the triangular wave output signal of the negative input end input oscillator module A8 of comparator A7, the output of comparator A7 is the output of PWM control module.

8. the electric pressure converter of band line loss compensation as claimed in claim 5, the power switch pipe M1 that it is characterized in that described switching tube and driver module thereof is the PMOS pipe, the source electrode of power switch pipe M1 is as the Vin port of DC-DC transducer, and the drain electrode of power switch pipe M1 is as the SW port of DC-DC transducer; Described power switch pipe M1 also can be positive-negative-positive triode, N channel enhancement metal-oxide-semiconductor or NPN type triode, if M1 is N channel enhancement metal-oxide-semiconductor or NPN type triode, driver module A4 generally adopts bootstrap approach.

9. the electric pressure converter of band line loss compensation as claimed in claim 5 is characterized in that described control circuit also comprises current sample module and current error amplification module:

The positive input terminal of described current sample module connects the CS+ port, negative input end connects the CS-port, pressure reduction between current sample module samples CS+ port and the CS-port, flowing through by the reflection of this voltage difference is connected across the output current of the sampling resistor Rsense between CS+ port and the CS-port;

The positive input terminal of described current error amplification module is imported the second reference voltage V REF2, negative terminal connects the output of current sample module, error between the current error amplification module amplified current sampling module output voltage and the second reference voltage V REF2, the output of current error amplification module connects the input of PWM control module.

10. the electric pressure converter of band line loss compensation as claimed in claim 9 is characterized in that described current sample module comprises that the positive input terminal of second operational amplifier A, 1, the second operational amplifier A 1 connects the CS+ port, and negative input end connects the CS-port; Described current error amplification module comprises the 3rd error amplifier A2, and the positive input terminal of the 3rd error amplifier A2 is imported the second reference voltage V REF2, and negative input end connects the output of second operational amplifier A 1.

11. the electric pressure converter of band line loss compensation as claimed in claim 9, it is characterized in that current error amplification module and voltage error amplification module can merge into a voltage error amplification module, described voltage error amplification module has two negative input ends, connects the output of current sample module and line loss compensating module respectively.

12. the electric pressure converter of band line loss compensation as claimed in claim 5 is characterized in that the line loss compensating module is a trsanscondutor, the pass of the output current of described trsanscondutor and trsanscondutor input voltage is: I ₁=(V ₁₊-V _1-) Gm, wherein, I ₁Be the output current of trsanscondutor, V _1-Be negative input end voltage, V ₁₊Be positive input terminal voltage.

13. the electric pressure converter of band line loss compensation as claimed in claim 5 is characterized in that described voltage error amplification module, PWM control module, drive circuit A4 and line loss compensating module are integrated in the chip.

14. the electric pressure converter of band line loss compensation as claimed in claim 13 is characterized in that described voltage error amplification module, PWM control module, drive circuit A4, power switch pipe M1 and line loss compensating module are integrated in the chip.

15. the electric pressure converter of band line loss compensation as claimed in claim 9 is characterized in that described voltage error amplification module, PWM control module, drive circuit A4, power switch pipe M1, line loss compensating module, current sample module and current error amplification module are integrated in the chip.

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