CN102347732B - Power control circuit and radio frequency power amplifier module with same - Google Patents

Abstract

The invention discloses a power control circuit and a radio frequency power amplifier module with the same. The output voltage of the power control circuit has a temperature coefficient in direct proportion to a control voltage signal; the radio frequency power amplifier module comprises a power amplifier and a power control circuit. The power control circuit and the radio frequency power amplifier module provide a variable power supply voltage for the power amplifier drive level, and can perform temperature change compensation to the power amplifier drive level according to the temperature characteristic of the output amplifying level of the power amplifier, so that the output power of the power amplifier is not fluctuated along with the temperature change.

Description

Power control circuit and there is the radio-frequency power amplifier module of power control circuit

Technical field

The present invention relates to RF application, relate in particular to power control circuit and there is the radio-frequency power amplifier module of power control circuit.

Background technology

Full ball Yi moves Tong Xin Xi System (Global System for Mobile Communications), i.e. GSM, is current application mobile phone standard the most widely.According to GSM joint committee, GSM has 1,500,000,000 user in the whole world, and user spreads all over more than 140 country.Because there are roaming agreement in many GSM Virtual network operators and other external operators, therefore when user is after other countries, still can continue to use their mobile phone.

In GSM cellular communication system, radio-frequency power amplifier module is the core component of realizing radiofrequency signal wireless transmission, and power control chip is the important component part in radio-frequency power amplifier module.Power control is a key technology that improves the availability of frequency spectrum and reduce power loss in GSM cellular communication system, under the prerequisite that keeps link speech quality, control as much as possible the transmitting power of mobile terminal and base station, thereby reach the object that reduces phase mutual interference between link.The major function that is integrated in the power control circuit in radio-frequency power amplifier module is the power output of power ratio control amplifier.In gsm wireless phone, adjustable output power signal must be followed a standard that is called " template pulse " (Burst Mask).Template pulse has defined rise time, fall time, duration and power grade corresponding to power-adjustable control signal.GSM signal comprises 8 equal time slots (time slots), and each time slot must be followed the standard of template pulse.Phone software produces a control signal that power is adjustable by the DAC (Digital to Analog Converter, digital to analog converter) in baseband circuit, is conventionally called V _rAMP.V _rAMPthe rise time of signal and the shape of fall time must be followed the standard of template pulse (Burst Mask).V _rAMPthe amplitude of signal determines the size of power output.

GSM radio-frequency power amplifier module is mainly made up of power control circuit and power amplifier two parts, as shown in Figure 1.Power amplifier is generally formed by driving stage and the cascade of output amplifier stage two parts.The power supply of driving stage is provided by power control circuit, by changing input control voltage signal V _rAMPvalue change output supply power voltage value.The power supply of output amplifier stage is directly provided by supply voltage.Gsm protocol regulation, mobile phone transmission power can be controlled by base station.Base station is by descending SACCH channel, give an order and control the power level of mobile phone, transmitting power between every two adjacent power grades differs 2dB, the maximum transmit power level of GSM900 frequency range is 5 (33dBm), minimum emissive power rank is 19 (5dBm), the maximum transmit power level of DCS1800 frequency range is 0 (30dBm), and minimum emissive power rank is 15 (0dBm).GSM standard is to have strict requirement for other power excursion of each power stage, is that power changes at ± 2dB for the standard that requires of greatest level.The variations in temperature of operational environment is one of principal element causing the variation of radio-frequency power amplifier power output.By design temperature compensating circuit in power control circuit, can realize the power output of power amplifier is compensated, but there is no at present ripe implementation.

Summary of the invention

For the above-mentioned problems in the prior art, the invention provides power control circuit and there is the radio-frequency power amplifier module of power control circuit.

The invention provides a kind of power control circuit of knowing clearly, the output voltage of power control circuit has the temperature coefficient that is proportional to control voltage signal.

In one example, power control circuit comprises low-dropout regulator and temperature-compensation circuit;

Control voltage signal input temp compensating circuit, temperature-compensation circuit is connected with low-dropout regulator;

The output voltage of low-dropout regulator has the temperature coefficient that is proportional to control voltage signal.

In one example, low-dropout regulator comprises the first operational amplifier 505, PMOS transistor 507, resistance R 5 ' and resistance R 6 '; Temperature-compensation circuit comprises the second operational amplifier 506, resistance R 1 ', resistance R 2 ', resistance R 3 ' and resistance R 4 ';

The source electrode of PMOS transistor 507 connects supply voltage, and the drain electrode of PMOS transistor 507 is successively through resistance R 5 ' and resistance R 6 ' ground connection, and the drain electrode of PMOS transistor 507 is driving stage 502,503 power supplies of power amplifier 501;

Node 508 between resistance R 5 ' and resistance R 6 ' is connected with the negative input of the first operational amplifier 505, and the output of the first operational amplifier 505 is connected with the grid of PMOS transistor 507;

Control voltage signal successively through resistance R 1 ' and resistance R 2 ' ground connection, node 510 between resistance R 1 ' and resistance R 2 ' is connected with the positive input of the second operational amplifier 506, and the output of the second operational amplifier 506 is successively through resistance R 3 ' and resistance R 4 ' ground connection;

Node 509 between resistance R 3 ' and resistance R 4 ' is connected with the negative input of the second operational amplifier 506, and the output of the second operational amplifier 506 is connected with the positive input of the first operational amplifier 505;

The temperature coefficient of resistance R 1 ' and resistance R 2 ' is different, and the temperature coefficient of resistance R 3 ' and resistance R 4 ' is identical, and the temperature coefficient of resistance R 5 ' and resistance R 6 ' is identical;

The voltage that the second operational amplifier 506 is exported is identical with the voltage of controlling voltage signal in the time of 30 ℃.

In one example, comprise low-dropout regulator, band-gap reference source circuit 810 and temperature-compensation circuit;

Band-gap reference source circuit 810 is used to temperature-compensation circuit that reference voltage is provided;

Temperature-compensation circuit is connected with low-dropout regulator;

The output voltage of low-dropout regulator has the temperature coefficient that is proportional to input control voltage signal.

In one example, low-dropout regulator comprises the 3rd operational amplifier 809, PMOS transistor 811, resistance R 11, resistance R 12 and resistance R 13; The source electrode of PMOS transistor 811 connects supply voltage, the drain electrode of PMOS transistor 811 is successively through resistance R 11, resistance R 12 and resistance R 13 ground connection, control the positive input that voltage signal is connected to the 3rd operational amplifier 809, the negative input of the 3rd operational amplifier 809 is connected to the node 812 between resistance R 11 and resistance R 12, the output of the 3rd operational amplifier 809 is connected to the grid of PMOS transistor 811, and the drain electrode of PMOS transistor 811 is driving stage 802,803 power supplies of power amplifier 801.

In one example, temperature-compensation circuit comprises buffer 805, the four-operational amplifier 806, the five operational amplifier 807, the six operational amplifiers 808, resistance R 1, resistance R 2, resistance R 3, resistance R 4, resistance R 5, resistance R 6, resistance R 7, resistance R 8, resistance R 9 and resistance R 10; Control the input that voltage signal is connected to buffer 805, the output of buffer 805 is successively through resistance R 1 and resistance R 2 ground connection; Node 814 between resistance R 1 and resistance R 2 is connected to the positive input of four-operational amplifier 806, the output of four-operational amplifier 806 is connected to the negative input of four-operational amplifier 806 through resistance R 3, the negative input of four-operational amplifier 806 is through resistance R 4 ground connection; The output of four-operational amplifier 806 is connected to the positive input of the 5th operational amplifier 807 through resistance R 5, the positive input of the 5th operational amplifier 807 is connected to the output of the 5th operational amplifier 807 through resistance R 7, the forward input of the 5th operational amplifier 807 also connects the first reference voltage through resistance R 6, and the negative input of the 5th operational amplifier 807 connects the second reference voltage; The output of the 5th operational amplifier 807 is connected to the positive input of the 6th operational amplifier 808 through resistance R 8, the positive input of the 6th operational amplifier 808 is connected to the output of the 6th operational amplifier 808 through resistance R 9, the negative input of the 6th operational amplifier 808 connects the 3rd reference voltage, and the output of the 6th operational amplifier 808 is connected to the node 813 between resistance R 12 and resistance R 13 through resistance R 10;

The first reference voltage, the second reference voltage and the 3rd reference voltage are provided by band-gap reference source circuit 510;

The temperature coefficient of resistance R 1 is different from the temperature coefficient of resistance R 2;

Resistance R 3, resistance R 4, resistance R 5, resistance R 6, resistance R 7, resistance R 8, resistance R 9, resistance R 10, resistance R 11, resistance R 12 is identical with the temperature coefficient of resistance R 13.

In one example, resistance R 5, resistance R 6 are identical with the resistance value of resistance R 7; Resistance R 8 is identical with the resistance value of resistance R 9; The magnitude of voltage of the 3rd reference voltage equals 1.5 times of magnitude of voltage of the second reference voltage;

PMOS manages the voltage of 811 outputs

$V_{\mathrm{out}\_\mathrm{Vcc}}=[1+\frac{R_{11}\·(R_1{R}_4{R}_{10}+R_2{R}_4{R}_{10}+R_1{R}_4{R}_{13}-R_2{R}_3{R}_{13})}{R_4\·(R_1+R_2)\·(R_{10}{R}_{12}+R_{10}{R}_{13}+R_{12}{R}_{13})}]\·V_{\mathrm{RAMP}}$

$-\frac{R_{11}{R}_{13}}{R_{10}{R}_{12}+R_{10}{R}_{13}+R_{12}{R}_{13}}\·\mathrm{Vref}1;$

Wherein V _rAMPfor controlling voltage signal, Vref1 is the first reference voltage;

The voltage of four-operational amplifier (806) output is identical with the voltage of controlling voltage signal in the time of 30 ℃.

The invention provides a kind of radio-frequency power amplifier module, comprise power amplifier and power control circuit, described power control circuit is described power control circuit.

In one example, power amplifier is formed by driving stage and output amplifier stage cascade.

The invention provides a kind of mobile terminal, comprise base band control chip 111, radio-frequency (RF) transceiver 112, radio-frequency power amplifier module 113, low noise amplifier 115, radio-frequency switch module 116 and antenna 114, radio-frequency power amplifier module 113 is described radio-frequency power amplifier module.

Radio-frequency power amplifier control circuit provided by the invention can compensates.This control circuit, for power amplifier driving stage provides variable supply power voltage, can carry out variations in temperature compensation to it according to the temperature characterisitic of power amplifier output amplifier stage simultaneously, makes the power output of power amplifier not vary with temperature and fluctuate.

Accompanying drawing explanation

Below in conjunction with accompanying drawing, the present invention is described in further detail, wherein:

Fig. 1 is conventional GSM power amplifier module;

Fig. 2 is the mode of operation of power amplifier;

Fig. 3 is that GSM power amplifier output power is with control signal V _rAMPchange curve;

Fig. 4 A is the temperature characterisitic of power amplifier output amplifier stage;

The temperature characterisitic of the power amplifier driving stage that Fig. 4 B needs while being design temperature compensation;

The output temperature characteristic of the power control circuit that Fig. 4 C needs while being design temperature compensation;

Fig. 5 embodiment of the present invention one schematic diagram;

The temperature characterisitic of Fig. 6 node 501 output voltage V 501;

Fig. 7 is application GSM power amplifier output power temperature characterisitic of the present invention;

Fig. 8 embodiment of the present invention two schematic diagrams;

Fig. 9 divider resistance output voltage V _bGat V _rAMPwhen=1.5V with temperature characteristics curve;

Figure 10 divider resistance output voltage V _bGunder different temperatures with V _rAMPthe curve changing;

Figure 11 temperature-compensation circuit output voltage V _rEFunder different temperatures with V _rAMPthe curve changing;

Figure 12 power control circuit output voltage V cc under different temperatures with V _rAMthe curve that P changes;

The mobile terminal that Figure 13 embodiment of the present invention provides.

Embodiment

Technical terms involved in the present invention is understandable for those skilled in the art.GSM radio-frequency power amplifier module is mainly made up of power control circuit and power amplifier two parts, as shown in Figure 1.Power amplifier is generally formed by driving stage and the cascade of output amplifier stage two parts, and the power supply Vcc of driving stage is provided by power control circuit, and the power supply of output amplifier stage is by supply voltage V _bATprovide.Power amplifier generally adopts the manufacture of gallium arsenide semiconductor (GaAs) technique, and power control circuit generally adopts the manufacture of complementary metal oxide semiconductors (CMOS) (CMOS) technique.

The compression of power amplification circuit gain is relevant with the size of input signal, and in the time that input signal maintains a very little signal, its input and outlet chamber maintain linear relation, i.e. the gain of power amplification circuit maintenance is constant; But in the time that input signal increases to certain limit, the gain of power amplification circuit will no longer keep constant, but be tending towards reducing, and this phenomenon is called gain compression.Conventionally, in the time of small signal gain decline 1dB, corresponding power output is 1dB gain compression point power, as shown in P_1dB in Fig. 2.In general, when power output is less than 1dB gain compression point power, power amplification circuit is operated in linear amplification mode, corresponding diagram 2 neutral line districts.In the time that input power is very large, power output no longer changes with input power, and power amplification circuit enters saturation condition, and power output is now called saturation power, saturation region in corresponding diagram 2.At the every increase of saturation region input power 3dB, power output variation is less than 0.1dB.Power output, between 1dB gain compression point power and saturation power, still has one period of stage slowly changing, quasi linear region auto in corresponding diagram 2.At the every increase of quasi linear region auto input power 1dB, power output increases by 0.1～0.5dB;

Under normal circumstances, the driving stage of power amplifier is operated under saturation region pattern, and output amplifier stage is operated under the pattern of linear zone.The input control voltage signal V of power control circuit _rAMPby the output voltage V cc of power ratio control control circuit, realize the function of the power output size of power ratio control amplifier.Input control voltage signal V _rAMPand relation between the power output Pout of power amplifier as shown in Figure 3.Adopt the temperature characterisitic of the power amplifier output amplifier stage of GaAs technology manufacture to there is following features: in-20 ℃～80 ℃ temperature ranges, output-power fluctuation changing value is 3dB; When 80 ℃ of states of high temperature, the gain of output amplifier stage is on the low side, and power output is on the low side; When low temperature high temperature-20 ℃ states, the gain of output amplifier stage is higher, and power output is higher, and as shown in Figure 4 A, wherein Pin is input power, and Pout is power output.

Because the power supply of power amplifier output amplifier stage is directly by supply voltage V _bATprovide, cannot carry out direct temperature-compensating to it.Therefore in order to realize, the power output of power amplifier is carried out to overall temperature-compensating, can be according to the temperature characterisitic of output amplifier stage, by design power control circuit, the driving stage of power amplifier is carried out the temperature-compensating of transition, make driving stage power output in the time of 80 ℃ of states of high temperature higher, when low temperature-20 ℃ states, power output is on the low side, as shown in Figure 4 B.Due at each V _rAMPthe lower corresponding power output temperature compensation value of value is all fixing 3dB, while being 10dBm (10mW) such as 30 ℃ of power outputs of normal temperature, need to compensate 3dB, while being 80 ℃ of high temperature, power output is 11.5dBm (14.1mW), and, power output is 8.5dBm (7.1mW) when the low temperature-20 ℃; When normal temperature power output 30dBm (1000mW), need to compensate 3dB, power output is 31.5dBm (1412mW) when 80 ℃ of high temperature, and, power output is 28.5dBm (708mW) when the low temperature-20 ℃.Therefore required power control circuit is at each control inputs voltage signal V _rAMPunder output voltage V cc there is unique temperature coefficient, the temperature coefficient of output voltage V cc is proportional to control inputs voltage signal V _rAMP, as shown in Figure 4 C.

Technical scheme provided by the invention makes the output voltage signal of power control circuit have temperature coefficient, and the size of temperature coefficient is proportional to the amplitude of input control voltage signal.Power control circuit can carry out variations in temperature compensation to it according to the temperature characterisitic of power amplifier output amplifier stage, makes the power output of power amplifier not vary with temperature and fluctuate.

Embodiment mono-

Fig. 5 is an embodiment of the present invention.Power amplifier module is made up of power amplifier 501 and power control circuit two parts.Power amplifier 501 is formed by driving stage 502, driving stage 503, output amplifier stage 504 cascades, power amplifier 501 received RF signal RF _iNand be enlarged into radiofrequency signal RF _oUToutput.The power supply Vcc of driving stage 502,503 is provided by power control circuit, and the power supply of output amplifier stage 504 is by supply voltage V _bATprovide.Power control circuit is mainly made up of variable low-dropout regulator LDO (Low voltage drop out regulator) and a temperature-compensation circuit of output voltage.

LDO is by operational amplifier 505, PMOS transistor 507, and resistance R 5 ', resistance R 6 ' forms, and resistance R 5 ' and resistance R 6 ' have identical temperature coefficient.The output of operational amplifier 506 is connected to the positive input of operational amplifier 505, and the output of operational amplifier 505 is connected to the grid of PMOS transistor 507, and the source electrode of PMOS transistor 507 is connected to supply voltage V _bAT, the output that the drain electrode of PMOS transistor 507 is LDO.The drain electrode contact resistance R5 ' of PMOS transistor 507, the negative input of operational amplifier 505 is connected to node 508, resistance R 6 ' connected node 508 and ground.The input/output relation expression formula of LDO is:

$V_{\mathrm{out}\_\mathrm{Vcc}}=(1+\frac{{R_5}^{\′}}{{R_6}^{\′}})\·V_{\mathrm{in}}---\left(1\right)$

The input control voltage that wherein Vin is LDO.

Temperature-compensation circuit is by operational amplifier 506, resistance R 1 ', and R2 ', R3 ', R4 ' forms.Wherein resistance R 1 ' and resistance R 2 ' have different temperatures coefficient, and resistance R 3 ' and resistance R 4 ' have identical temperature coefficient.In general cmos semiconductor technique, the resistance with different temperature coefficients can be provided, as polysilicon resistance, semiconductor resistor, metallic resistance, etc.Resistance R 1 ' one end connects input control signal V _rAMP, other end connected node 510.Resistance R 2 ' one end connected node 510, other end ground connection.Node 510 is connected to the positive input of operational amplifier 506.Node 509 is connected to the negative input of operational amplifier.The output of resistance R 3 ' one end concatenation operation amplifier 506, the other end is connected to node 509.Resistance R 4 ' one end is connected to node 509, other end ground connection.

Power control circuit to the temperature compensation principle of power amplifier is: input control voltage signal V _rAMPoutput voltage V 510 at node 510 after the bleeder circuit of resistance R 1 ' and R2 ' has temperature coefficient, and the size of temperature coefficient can regulate by the ratio of adjusting resistance R1 ' and R2 '.The temperature coefficient of output voltage V 510 is proportional to input control voltage signal V simultaneously _rAMPvalue, as shown in Figure 6.By the ratio of adjusting resistance R3 ' and R4 ', the output voltage V out_temp that makes operational amplifier 506 equals input control voltage signal V in the time of 30 ℃ of normal temperature _rAMPvalue.When 30 ℃ of normal temperature, the input control voltage value size of LDO equals V _rAMPvalue, the output voltage V cc of LDO has the control inputs of being proportional to voltage signal V _rAMPtemperature coefficient, as shown in Figure 4 C.Therefore realized the temperature compensation function of power amplifier, as shown in Figure 7, in the time that temperature changes within the scope of-20 ℃ to 80 ℃, the power output of power amplifier does not vary with temperature and fluctuates compensation effect.

Embodiment bis-

Fig. 8 is another specific embodiments of the present invention.Whole power amplifier module is made up of two parts, power amplifier 801 and power control circuit.Power amplifier 801 is formed by driving stage 802, driving stage 803, output amplifier stage 804 cascades, power amplifier 801 received RF signal RF _iNand be enlarged into radiofrequency signal RF _oUToutput.The power supply Vcc of driving stage is provided by power control circuit, and the power supply of output amplifier stage 804 is by supply voltage V _bATprovide.Power control circuit is mainly made up of variable low-dropout regulator (LDO), band-gap reference source circuit 810 and a temperature-compensation circuit of output voltage.

LDO is by operational amplifier 809, PMOS transistor 811, and resistance R 11, resistance R 12, resistance R 13 forms.Input control signal V _rAMPbe connected to the positive input of operational amplifier 809, the output of operational amplifier 809 is connected to the grid of PMOS transistor 811, and the source electrode of PMOS transistor 811 is connected to supply voltage V _bAT, the output that the transistorized drain electrode of PMOS is LDO.The drain electrode contact resistance R11 of PMOS transistor 811, resistance R 11 feeds back to the negative input of operational amplifier 809 by node 812.Resistance R 12 between node 812 and node 813, resistance R 13 connected nodes 813 and ground.The input/output relation expression formula of LDO is:

$V_{\mathrm{out}\_\mathrm{Vcc}}=(1+\frac{R_{11}}{R_{12}+R_{13}})\·V_{\mathrm{RAMP}}---\left(2\right)$

Band-gap reference source circuit 810 is exported three not with temperature and supply voltage V _bATthe reference voltage signal Vref1, Vref2 and the Vref3 that change.

Temperature-compensation circuit is mainly by buffer 805, operational amplifier 806, and operational amplifier 807, operational amplifier 808 and some resistance form.Input control signal V _rAMPbe connected to the input of buffer 805, the output contact resistance R1 of buffer, the other end connected node 814 of resistance R 1, resistance R 2 connected nodes 814 and ground.Resistance R 1 and resistance R 2 have different temperature coefficient (TC).The positive input connected node 814 of operational amplifier 806, the output of operational amplifier 806 feeds back to its negative input by resistance R 3, the negative input of resistance R 4 concatenation operation amplifiers 806 and ground.The output of resistance R 5 concatenation operation amplifiers 806 and the positive input of operational amplifier 807.The positive input of resistance R 6 one end concatenation operation amplifiers 807, the other end connects reference voltage Vref 1.Output and the positive input of resistance R 7 concatenation operation amplifiers 807.The negative input of reference voltage Vref 2 concatenation operation amplifiers 807.The output of resistance R 8 concatenation operation amplifiers 807 and the positive input of operational amplifier 808.Output and the positive input of resistance R 9 concatenation operation amplifiers 808.The negative input of reference voltage Vref 3 concatenation operation amplifiers 808.The output 817 of resistance R 10 concatenation operation amplifiers 808 and the node 813 of LDO.

Buffer 805 is unity gain amplifiers.Input control signal V _rAMPafter buffer 805, its current driving ability is strengthened.Resistance R 1 and R2 have different temperature coefficient (TC), and the temperature variant expression formula of its resistance value is:

R1(T)＝R0 ₁·(1+TC1×dT) (3)

R2(T)＝R0 ₂·(1+TC2×dT) (4)

Wherein TC1, TC2 represent respectively the temperature coefficient of R1 and R2, and T represents temperature, dT=T-30 ℃.R0 ₁=RSH ₁× L/W, R0 ₂=RSH ₂× L/W, RSH is square resistance rate, and W represents the width of resistance, and L represents the length of resistance.In general cmos semiconductor technique, all provide the resistance with different temperature coefficients to select for designer, as polysilicon resistance, semiconductor resistor, metallic resistance, etc.

Base band control signal V _rAMPafter buffer 805, in the output voltage V of node 814 _bGhave temperature coefficient, its expression formula is,

$V_{\mathrm{BG}}=\frac{R2}{R1+R2}\&CenterDot;V_{\mathrm{RAMP}}=\frac{{\mathrm{<figure-callout\; id="0"\; label="R"\; filenames="HDA0000082326500000072.png,HDA0000082326500000082.png"\; state="\{\{state\}\}">R</figure-callout>}0}_2\&CenterDot;(1+\mathrm{TC}2\&times;\mathrm{dT})}{{\mathrm{<figure-callout\; id="0"\; label="R"\; filenames="HDA0000082326500000072.png,HDA0000082326500000082.png"\; state="\{\{state\}\}">R</figure-callout>}0}_1\&CenterDot;(1+\mathrm{TC}1\&times;\mathrm{dT})+{\mathrm{<figure-callout\; id="0"\; label="R"\; filenames="HDA0000082326500000072.png,HDA0000082326500000082.png"\; state="\{\{state\}\}">R</figure-callout>}0}_2\&CenterDot;(1+\mathrm{TC}2\&times;\mathrm{dT})}\&CenterDot;V_{\mathrm{RAMP}}---\left(5\right)$

Select the temperature coefficient of resistance R 1 to be greater than the temperature coefficient of R2, TC1 is greater than TC2, works as V _rAMPwhen=1.5V, V _bGtemperature variant curve as shown in Figure 9.V _bGwith V _rAMPchange curve under different temperatures as shown in figure 10.

The output node 815 of operational amplifier 806, its output voltage V _rEFexpression formula be,

V _REF＝V _BG·(1+R3/R4) (6)

By the ratio of adjusting resistance R3 and R4, make the output voltage V of operational amplifier 806 _rEFin the time of 30 ℃ of normal temperature, equal input control voltage signal V _rAMPvalue.

V _rEFwith V _rAMPchange curve under different temperatures as shown in figure 11.

Resistance R 5, R6, R7 and operational amplifier 807 have formed an adder operation circuit, make R5=R6=R7, in the output voltage expression formula of node 816 be,

V816＝3Vref2-Vref1-VREF (7)

Resistance R 8, R9 and operational amplifier 808 have formed a subtraction circuit, make R9=R8, in the output voltage expression formula of node 817 be,

V817＝2Vref3-V816＝2Vref3-3Vref2+Vref1+VREF (8)

By the output voltage values of bandgap engineered reference source circuit 810, make 2Vref3=3Vref2, the output voltage of node 817 becomes,

V817＝Vref1+VREF (9)

In the time that temperature changes, the output voltage of operational amplifier 808 can change thereupon, by resistance R 10, the information of variations in temperature is delivered to node 813 places of LDO, adjusts the output voltage V cc of LDO, calculates relational expression as follows,

$V_{\mathrm{out}\_\mathrm{Vcc}}=[1+\frac{R_{11}\&CenterDot;(R_1{R}_4{R}_{10}+R_2{R}_4{R}_{10}+R_1{R}_4{R}_{13}-R_2{R}_3{R}_{13})}{R_4\&CenterDot;(R_1+R_2)\&CenterDot;(R_{10}{R}_{12}+R_{10}{R}_{13}+R_{12}{R}_{13})}]\&CenterDot;V_{\mathrm{RAMP}}---\left(10\right)$

$-\frac{R_{11}{R}_{13}}{R_{10}{R}_{12}+R_{10}{R}_{13}+R_{12}{R}_{13}}\&CenterDot;\mathrm{Vref}1$

Describe the derivation of this expression formula below in detail.

In Fig. 8, the output voltage of node 817 is

$\mathrm{<figure-callout\; id="817"\; label="V"\; filenames="HDA0000082326500000061.png"\; state="\{\{state\}\}">V</figure-callout>}817=\mathrm{Vref}1+\mathrm{VREF}=\mathrm{Vref}1+\mathrm{VBG}(1+R3/R4)$

$=\mathrm{Vref}1+V_{\mathrm{RAMP}}\left(\frac{R2}{R1+R2}\right)(1+\frac{R3}{R4})---\left(11\right)$

If the output current I of LDO, the output voltage of node 812 is V ₈₁₂, the output voltage of node 813 is V ₈₁₃, according to kirchhoff electric current and voltage law, the electric current of inflow and outflow circuit node is identical, therefore

$I=\frac{V_{\mathrm{out}\_\mathrm{Vcc}}-V_{812}}{R11}---\left(12\right)$

$I=\frac{V_{812}-V_{813}}{R12}---\left(13\right)$

$I+\frac{V_{817}-V_{813}}{R10}=\frac{V_{813}}{R13}---\left(14\right)$

V812＝V _RAMP (15)

By expression formula (12)～(15), cancellation I and V ₈₁₃, obtain LDO output voltage and express formula

$V_{\mathrm{out}\_\mathrm{Vcc}}=[1+\frac{R_{10}{R}_{11}+R_{11}{R}_{13}}{R_{10}{R}_{12}+R_{10}{R}_{13}+R_{12}{R}_{13}}]\&CenterDot;V_{\mathrm{RAMP}}-\frac{R_{11}{R}_{13}}{R_{10}{R}_{12}+R_{10}{R}_{13}+R_{12}{R}_{13}}\&CenterDot;V817---\left(16\right)$

(11) are brought into expression formula (16), obtain expression formula (10).Owing to only having resistance R 1 and R2 to have different temperature coefficients, the temperature coefficient of other resistance is identical.Therefore from expression formula (10), can find out, this has temperature coefficient to only have R1/ (R1+R2), again because this and V _rAMPmultiply each other, therefore the output voltage V cc of rate control circuit has to be proportional to and controls voltage signal V _rAMPtemperature coefficient.

Adopt technique for temperature compensation power control circuit output voltage V cc afterwards with controlling voltage signal V _rAMPcurve of output under different temperatures as shown in figure 12.As can see from Figure 12, along with controlling voltage signal V _rAMPthe increase of value, the magnitude of voltage of temperature-compensating is corresponding increase also.The power output of power amplifier is with controlling voltage signal V _rAMPas shown in Figure 7, in the time that temperature changes within the scope of-20 ℃ to 80 ℃, the power output of power amplifier does not vary with temperature and fluctuates curve of output under different temperatures.

Figure 13 has shown the mobile terminal structure schematic diagram that the embodiment of the present invention provides.Mobile terminal baseband control chip 111, radio-frequency (RF) transceiver 112, radio-frequency power amplifier module 113, low noise amplifier module 115, radio-frequency switch module 116, and antenna 114.Base band control chip 111 is for the synthesis of the baseband signal that will launch, or the baseband signal receiving is decoded; Radio-frequency (RF) transceiver 112, the baseband signal of coming from 111 transmission of base band control chip is processed and radio frequency signal generation, and generated radiofrequency signal is sent to radio-frequency power amplifier module 113, or the radiofrequency signal of coming from low noise amplifier module 115 transmission is processed and generated baseband signal, and generated baseband signal is sent to base band control chip 111; Radio-frequency power amplifier module 113, for carrying out the processing such as power amplification to the radiofrequency signal of coming from radio-frequency (RF) transceiver 112 transmission.Low noise amplifier module 115, for receiving signal and will being sent to radio-frequency (RF) transceiver 112 after this reception signal processing; Radio-frequency switch module 116, it is connected with low noise amplifier module 115 and antenna 114 with radio-frequency power amplifier module 113, and for receiving from the external world, signal is delivered to low noise amplifier module 115 or transmitting transmits from radio-frequency power amplifier module 113 the signal of coming.

Particularly, while carrying out signal transmitting, base band control chip 111 is compiled into the information that will launch base band code (baseband signal) and is transferred to radio-frequency (RF) transceiver 112, radio-frequency (RF) transceiver 112 is processed radio frequency signal generation to this baseband signal, and this radio signal transmission is arrived to radio-frequency power amplifier module 113, radio-frequency power amplifier module 113 carries out power amplification and outwards launches by radio-frequency switch module 116 and antenna 114 transmit the radiofrequency signal of coming from radio-frequency (RF) transceiver 112; While carrying out signal reception, low noise amplifier module 115 by by radio-frequency switch module 116 and antenna 114 by the radio signal transmission receiving to radio-frequency signal transceiver 112, the radiofrequency signal receiving from low noise amplifier module 115 is converted to baseband signal by radio-frequency signal transceiver 112, and this base band signal transmission is arrived to base band control chip 111, the baseband signal that finally will be come from radio-frequency (RF) transceiver transmission by base band control chip 111 be interpreted as reception information.

Alternatively, the described information that will launch or reception information can comprise audio-frequency information, address information (such as phone number or station address), Word message (such as short message word or website word), pictorial information etc.

The primary clustering of described base band control chip is processor (as DSP, ARM etc.) and internal memory (as SRAM, Flash etc.).Alternatively, this base band control chip is realized by one chip.

The foregoing is only the preferred embodiment of the present invention, but protection range of the present invention is not limited to this.Any those skilled in the art, in technical scope disclosed by the invention, all can carry out suitable change or variation to it, and this change or change all should be encompassed in protection scope of the present invention within.

Claims (6)

1. a power control circuit, is characterized in that, the output voltage of power control circuit has the temperature coefficient that is proportional to control voltage signal, and power control circuit comprises low-dropout regulator and temperature-compensation circuit;

Control voltage signal input temp compensating circuit, temperature-compensation circuit is connected with low-dropout regulator;

The output voltage of low-dropout regulator has the temperature coefficient that is proportional to control voltage signal,

Wherein, low-dropout regulator comprises the first operational amplifier (505), PMOS transistor (507), resistance R 5 ' and resistance R 6 '; Temperature-compensation circuit comprises the second operational amplifier (506), resistance R 1 ', resistance R 2 ', resistance R 3 ' and resistance R 4 ';

The source electrode of PMOS transistor (507) connects supply voltage, the drain electrode of PMOS transistor (507) is successively through resistance R 5 ' and resistance R 6 ' ground connection, and the drain electrode of PMOS transistor (507) is the driving stage of power amplifier (501) (502,503) power supply;

Node (508) between resistance R 5 ' and resistance R 6 ' is connected with the negative input of the first operational amplifier (505), and the output of the first operational amplifier (505) is connected with the grid of PMOS transistor (507);

Control voltage signal successively through resistance R 1 ' and resistance R 2 ' ground connection, node (510) between resistance R 1 ' and resistance R 2 ' is connected with the positive input of the second operational amplifier (506), and the output of the second operational amplifier (506) is successively through resistance R 3 ' and resistance R 4 ' ground connection;

Node (509) between resistance R 3 ' and resistance R 4 ' is connected with the negative input of the second operational amplifier (506), and the output of the second operational amplifier (506) is connected with the positive input of the first operational amplifier (505);

The temperature coefficient of resistance R 1 ' and resistance R 2 ' is different, and the temperature coefficient of resistance R 3 ' and resistance R 4 ' is identical, and the temperature coefficient of resistance R 5 ' and resistance R 6 ' is identical;

The voltage of the second operational amplifier (506) output is identical with the voltage of controlling voltage signal in the time of 30 ℃.

2. a power control circuit, is characterized in that, the output voltage of power control circuit has the temperature coefficient that is proportional to control voltage signal, comprises low-dropout regulator, band-gap reference source circuit (810) and temperature-compensation circuit;

Band-gap reference source circuit (810) is used to temperature-compensation circuit that reference voltage is provided;

Temperature-compensation circuit is connected with low-dropout regulator;

The output voltage of low-dropout regulator has the temperature coefficient that is proportional to input control voltage signal,

Wherein, low-dropout regulator comprises the 3rd operational amplifier (809), PMOS transistor (811), resistance R 11, resistance R 12 and resistance R 13, the source electrode of PMOS transistor (811) connects supply voltage, the drain electrode of PMOS transistor (811) is successively through resistance R 11, resistance R 12 and resistance R 13 ground connection, control the positive input that voltage signal is connected to the 3rd operational amplifier (809), the negative input of the 3rd operational amplifier (809) is connected to the node (812) between resistance R 11 and resistance R 12, the output of the 3rd operational amplifier (809) is connected to the grid of PMOS transistor (811), the drain electrode of PMOS transistor (811) is the driving stage (802 of power amplifier (801), 803) power supply,

Wherein, temperature-compensation circuit comprises buffer (805), four-operational amplifier (806), the 5th operational amplifier (807), the 6th operational amplifier (808), resistance R 1, resistance R 2, resistance R 3, resistance R 4, resistance R 5, resistance R 6, resistance R 7, resistance R 8, resistance R 9 and resistance R 10; Control the input that voltage signal is connected to buffer (805), the output of buffer (805) is successively through resistance R 1 and resistance R 2 ground connection; Node (814) between resistance R 1 and resistance R 2 is connected to the positive input of four-operational amplifier (806), the output of four-operational amplifier (806) is connected to the negative input of four-operational amplifier (806) through resistance R 3, the negative input of four-operational amplifier (806) is through resistance R 4 ground connection; The output of four-operational amplifier (806) is connected to the positive input of the 5th operational amplifier (807) through resistance R 5, the positive input of the 5th operational amplifier (807) is connected to the output of the 5th operational amplifier (807) through resistance R 7, the forward input of the 5th operational amplifier (807) also connects the first reference voltage through resistance R 6, and the negative input of the 5th operational amplifier (807) connects the second reference voltage; The output of the 5th operational amplifier (807) is connected to the positive input of the 6th operational amplifier (808) through resistance R 8, the positive input of the 6th operational amplifier (808) is connected to the output of the 6th operational amplifier (808) through resistance R 9, the negative input of the 6th operational amplifier (808) connects the 3rd reference voltage, and the output of the 6th operational amplifier (808) is connected to the node (813) between resistance R 12 and resistance R 13 through resistance R 10;

The first reference voltage, the second reference voltage and the 3rd reference voltage are provided by band-gap reference source circuit (510);

The temperature coefficient of resistance R 1 is different from the temperature coefficient of resistance R 2;

Resistance R 3, resistance R 4, resistance R 5, resistance R 6, resistance R 7, resistance R 8, resistance R 9, resistance R 10, resistance R 11, resistance R 12 is identical with the temperature coefficient of resistance R 13.

3. power control circuit as claimed in claim 2, is characterized in that, resistance R 5, resistance R 6 are identical with the resistance value of resistance R 7; Resistance R 8 is identical with the resistance value of resistance R 9; The magnitude of voltage of the 3rd reference voltage equals 1.5 times of magnitude of voltage of the second reference voltage;

The voltage of PMOS pipe (811) output

$\begin{array}{c}{V}_{\mathrm{out}\_\mathrm{Vcc}}=[1+\frac{R_{11}\&CenterDot;(R_1{R}_4{R}_{10}+R_2{R}_4{R}_{10}+R_1{R}_4{R}_{13}-R_2{R}_3{R}_{13})}{R_4\&CenterDot;(R_1+R_2)\&CenterDot;(R_{10}{R}_{12}+R_{10}{R}_{13}+R_{12}{R}_{13})}]\&CenterDot;V_{\mathrm{RAMP}}\\ -\frac{R_{11}{R}_{13}}{R_{10}{R}_{12}+R_{10}{R}_{13}+R_{12}{R}_{13}}\&CenterDot;\mathrm{Vref}1\end{array};$

Wherein V _rAMPfor controlling voltage signal, Vref1 is the first reference voltage;

The voltage of four-operational amplifier (806) output is identical with the voltage of controlling voltage signal in the time of 30 ℃.

4. a radio-frequency power amplifier module, comprises power amplifier and power control circuit, it is characterized in that, described power control circuit is the power control circuit described in claim 1-3 any one.

5. radio-frequency power amplifier module as claimed in claim 4, is characterized in that, power amplifier is formed by driving stage and output amplifier stage cascade.

6. a mobile terminal, comprise base band control chip (111), radio-frequency (RF) transceiver (112), radio-frequency power amplifier module (113), low noise amplifier (115), radio-frequency switch module (116) and antenna (114), it is characterized in that, radio-frequency power amplifier module (113) is the radio-frequency power amplifier module as described in claim 4 or 5.

Images