CN111917385A

CN111917385A - Amplifier device

Info

Publication number: CN111917385A
Application number: CN202010379589.6A
Authority: CN
Inventors: 陈智圣; 彭天云; 罗弘家
Original assignee: Richwave Technology Corp
Current assignee: Richwave Technology Corp
Priority date: 2019-05-08
Filing date: 2020-05-07
Publication date: 2020-11-10
Also published as: TWI724893B; TW202042498A; TW202114345A; TWI787689B

Abstract

An amplifier device includes an amplifying unit and a bias module. The amplifying unit has a first terminal coupled to a voltage source for receiving a power voltage, a second terminal for receiving an input signal, and a third terminal coupled to a first reference potential terminal. The first reference potential terminal is used for receiving a first reference potential. The first end of the amplifying unit is used for outputting the output signal amplified by the amplifying unit. The bias module is coupled to the second end of the amplifying unit and used for receiving the voltage signal to provide a bias current to the amplifying unit. The voltage signal is a variable voltage. The supply current flows into the amplifying unit and is adjusted according to the voltage signal so as to maintain the supply current within a preset range.

Description

Amplifier device

Technical Field

The present invention relates to an amplifier device, and more particularly, to an amplifier device capable of adjusting a bias current and providing compensation according to various factors.

Background

In wireless communication technology, amplifier devices are often used to amplify signals to improve the quality of transmitted and received signals. However, as applications become more complex, the factors to be considered in designing the amplifier device also increase relatively to avoid affecting the performance of the amplifier device.

Disclosure of Invention

The embodiment of the invention provides an amplifier device, which comprises an amplifying unit and a bias module. The amplifying unit has a first terminal coupled to the voltage source for receiving the power voltage, a second terminal for receiving the input signal, and a third terminal coupled to a first reference potential terminal for receiving a first reference potential, wherein the first terminal of the amplifying unit is used for outputting the output signal amplified by the amplifying unit. The bias module is coupled to the second end of the amplifying unit and used for receiving a voltage signal to provide a bias current to the amplifying unit, wherein the voltage signal is a variable voltage. The supply current flows into the amplifying unit and is adjusted according to the voltage signal so as to maintain the supply current within a preset range.

Drawings

FIG. 1 is a schematic diagram of an amplifier device according to an embodiment of the present invention.

Fig. 2 shows the voltage response of the uncompensated supply current.

FIG. 3 shows a voltage compensation scheme using bias current in an embodiment of the present invention.

Fig. 4 is a schematic diagram of the variable current source in fig. 1.

FIG. 5 is a schematic diagram of another variable current source shown in FIG. 1.

FIG. 6 is a schematic diagram of another amplifier device according to an embodiment of the present invention.

FIG. 7 is a schematic diagram of another amplifier device according to an embodiment of the present invention.

FIG. 8 is a schematic diagram of another amplifier device according to an embodiment of the present invention.

[ notation ] to show

2: amplifier arrangement

11: amplification unit

12 biasing module

20. 30, 155, 1608 reference potential terminal

24: voltage source

130. 132 curve of

134. 136, 140, 142 line segment

151. 153, 1601 to 1607 Signal terminal

152 first resistance selection circuit

154 second resistance selection circuit

156 voltage to current converter

157. 158 switch control terminal

190 bias voltage source

Variable current source 1200

1201. 1206 transistor

1203. 1207, Rp 1-Rp 6, Rn 1-Rn 6, RF1 resistance

1204. 1205: diode

Ibias current

Icc supply current

OP operational amplifier

S1 input signal

S2 output signal

SW1, SW2 switches

V1 supply voltage

VBG2, VBG3, Vdet02, Vr5 reference signal

VCC1 Voltage Signal

Vdet2 power signal

Vo output voltage

VPTAT2, VD0, Vat temperature signals

Vref1, Vref5 reference potential

Vsource supply voltage

Detailed Description

Fig. 1 is a schematic diagram of an amplifier device 2 according to an embodiment of the present invention. The amplifier device 2 includes an amplifying unit 11 and a bias module 12. The amplifying unit 11 may draw a supply current Icc from a voltage source 24, the voltage source 24 being configured to receive a supply voltage Vsource. The supply voltage Vsource is a time-varying voltage. When the supply voltage Vsource changes with time, the supply current Icc also changes. Fig. 2 shows the voltage response of the uncompensated supply current Icc, with the horizontal axis representing the supply voltage Vsource in volts (V) and the vertical axis representing the supply current Icc in milliamperes (mA). Curve 130 represents the ideal supply current Icc, curve 132 represents the actual supply current Icc, and

line segments

134 and 136 represent first and second approximate curves, respectively, of the actual supply current Icc. In one embodiment, the supply voltage Vsource may vary from 5.5V to 3.2V over a period of time, and the amplifying unit 11 may operate within the range of the supply voltage Vsource. Ideally, the supply current Icc should be substantially maintained at 140mA as shown by curve 130. In practice, the supply current Icc may vary from 120mA to 160mA, as shown by curve 132. For supply voltages Vsource in the range between 3.2V and 4.7V, curve 132 may approximate line segment 134, and for supply voltages Vsource in the range between 4.7V and 5.5V, curve 132 may approximate line segment 136.

Line segments

134 and 136 may have a first slope and a second slope, respectively.

FIG. 3 shows a voltage compensation scheme using bias current Ibias in an embodiment of the present invention. The

segments

140 and 142 represent the bias current Ibias generated by the bias module 12 for the supply voltage Vsource being less than the threshold and exceeding the threshold, respectively. The threshold may be substantially selected to be the intersection of the

line segments

134 and 136 of FIG. 2, such as 4.7

V. Segments

140 and 142 show that the bias current Ibias is negatively related to the supply voltage Vsource of FIG. 2. In addition, line segment 140 has a first inverse slope, corresponding to the first slope of line segment 134 of FIG. 2, and line segment 142 has a second inverse slope, corresponding to the second slope of line segment 136 of FIG. 2. The first inverse slope may be negatively correlated to the first slope, and the second inverse slope may be negatively correlated to the second slope. The amplifier device 2 can adjust the bias current Ibias according to the

line segments

140 and 142 to compensate for the variation of the supply voltage Vsource with time, so that the amplifying unit 11 can maintain operation with a substantially constant supply current Icc, for example, 140mA, and the performance of the amplifier device 2 is improved. In some embodiments, the bias module 12 may adjust the bias current Ibias according to the segment 140 for a supply voltage Vsource less than 4.7V, and the bias module 12 may adjust the bias current Ibias according to the segment 142 for a supply voltage Vsource exceeding 4.7V. In some embodiments, the amplifier device 2 can compensate for the variation of the supply voltage Vsource according to the line segment 140 or the line segment 142.

Although only 2

segments

134 and 136 are used to approximate the actual supply current Icc (curve 132) in fig. 2, one skilled in the art can use more than 2 approximation curves to approximate the actual supply current Icc, and use more than 2 corresponding lines negatively correlated to the more than 2 approximation curves to simulate the bias current Ibias in the desired operating range, and use 2 or more thresholds to determine which of the more than 2 corresponding lines is to be used to simulate the bias current Ibias, thereby compensating for the variation of the supply voltage Vsource. The inverse slope and threshold values of the segment of the analog bias current Ibias are not limited to the embodiment shown in fig. 3, and may be selected based on practical applications and design requirements.

Referring to fig. 1, the amplifying unit 11 has a first terminal coupled to the voltage source 24 for receiving the power voltage Vsource and for flowing the power current Icc, a second terminal for receiving the input signal S1, and a third terminal coupled to the reference potential terminal 20. The amplifying unit 11 may be a Bipolar Junction Transistor (BJT), and may be used as a power amplifier or a low noise amplifier. The amplifying unit 11 may be biased by a bias current Ibias to amplify the input signal S1, and the first terminal of the amplifying unit 11 outputs the output signal S2 amplified by the amplifying unit 11. The reference potential terminal 20 may receive a reference potential Vref 1. The reference potential Vref1 may be a ground reference potential or other reference potential.

The bias module 12 may be coupled to the second terminal of the amplifying unit 11, and may receive a voltage signal VCC1 to provide a bias current Ibias to the amplifying unit 11. The voltage signal VCC1 may be substantially positively correlated to the time-varying power supply voltage Vsource, and thus the voltage signal VCC1 may also be a time-varying variable voltage. In some embodiments, the voltage signal VCC1 may be a portion of the supply voltage Vsource, which may be divided by a voltage divider to obtain the voltage signal VCC1, where VCC1 is vsourcek, and K may be 0.5. In other embodiments, the voltage signal VCC1 may be substantially equal to the supply voltage Vsource.

Since the voltage signal VCC1 is substantially positively correlated to the power supply voltage Vsource, and in fig. 3, the

segments

140 and 142 can also represent that the bias current Ibias is substantially negatively correlated to the voltage signal VCC1, the bias module 12 can adjust the bias current Ibias according to the voltage signal VCC 1. A decrease in the supply voltage Vsource will increase the bias current Ibias and thus the supply current Icc. Conversely, an increase in the supply voltage Vsource will decrease the bias current Ibias and thus the supply current Icc. In this way, the supply current Icc varying with variations in the supply voltage Vsource can be compensated, and the supply current Icc can be adjusted according to the voltage signal VCC1 to maintain the supply current Icc within a predetermined range, such as within ± 3% of 140 mA.

The bias module 12 may include a variable current source 1200. In some embodiments, the variable current source 1200 may be a variable resistor for adjusting the bias current Ibias according to the voltage signal VCC 1. In other embodiments, as shown in fig. 4, the variable current source 1200 may include

signal terminals

151 and 153, a reference potential terminal 155, an operational amplifier (OP amp) OP, a first resistor selection circuit 152, a second resistor selection circuit 154, resistors Rp1 and Rn1, RF and RF1, a voltage-to-current converter 156, and switch

control terminals

157 and 158. In some embodiments, the resistance value of the resistor Rn1 may be adjusted to selectively remove the resistor RF1 from the variable current source 1200. The variable current source 1200 receives the voltage signal VCC1 and the reference signal VBG2 to generate the bias current Ibias according to the

segments

140 and 142 in fig. 3. The reference signal VBG2 may be a bandgap reference voltage (bandgap) or other reference voltage, and the reference signal VBG2 may be substantially constant with respect to variations in the supply voltage Vsource.

The operational amplifier OP may have a first input terminal, a second input terminal and an output terminal. The first input terminal is a forward terminal, the second input terminal is a reverse terminal, and the output terminal is used for outputting the output voltage Vo. The first input terminal of the operational amplifier OP may be coupled to the signal terminal 151 and receive the reference signal VBG2, and the second input terminal of the operational amplifier OP may be coupled to the signal terminal 153 and receive the voltage signal VCC 1. The output terminal of the operational amplifier OP can output the output voltage Vo according to the difference between the reference signal VBG2 and the voltage signal VCC 1. In other embodiments, the operational amplifier OP may be an adder (adder).

The voltage-to-current converter 156 may include a first terminal coupled to the output terminal of the operational amplifier OP and a second terminal coupled to the second terminal of the amplifying unit 11. The voltage-to-current converter 156 may convert the output voltage Vo to a bias current Ibias. The voltage-to-current converter 156 may be a Metal Oxide Semiconductor Field Effect Transistor (MOSFET), a BJT, or other type of transistor.

The resistor RF may include a first terminal coupled to the second input terminal of the operational amplifier OP and a second terminal coupled to the output terminal of the operational amplifier OP. The resistor RF1 may include a first terminal coupled to the first terminal of the resistor RF and a second terminal coupled to the reference potential terminal 155. the reference potential terminal 155 may receive the reference potential Vref 5. The reference potential Vref5 may be a ground reference potential or other reference potential. In some embodiments, the reference potential Vref5 and the reference potential Vref1 can have substantially the same potential. In some embodiments, the resistors RF, RF1 may have substantially the same resistance value. In some embodiments, the resistors RF, RF1 may be variable resistors. In some embodiments, the resistance of the resistor RF1 can be set to be a multiple of the resistance of the resistor RF to change the slope of the

segments

140 and 142 in fig. 3.

The resistor Rp1 includes a first terminal coupled to the signal terminal 151 via the first resistor selection circuit 152, and a second terminal coupled to a first input terminal of the operational amplifier OP. The resistor Rn1 may include a first terminal coupled to the signal terminal 153 via the second resistor selection circuit 154, and a second terminal coupled to a second input terminal of the operational amplifier OP. The resistances Rp1, Rn1 may be variable resistances. The first resistor selection circuit 152 may include a first terminal coupled to the signal terminal 151 and a second terminal coupled to a first terminal of the resistor Rp 1. The second resistor selection circuit 154 may include a first terminal coupled to the signal terminal 153 and a second terminal coupled to the first terminal of the resistor Rn 1. The first resistance selection circuit 152 may include a switch SW1 and a resistance Rp 2. The switch SW1 may include a first terminal coupled to the first terminal of the first resistance selection circuit 152, a second terminal coupled to the second terminal of the first resistance selection circuit 152, and a control terminal coupled to the switch control terminal 157. Switch control 157 may receive a first control signal to turn on or off switch SW 1. The resistor Rp2 may be coupled between the first terminal of the switch SW1 and the second terminal of the switch SW 1. The second resistance selection circuit 154 may include a switch SW2 and a resistance Rn 2. The switch SW2 may include a first terminal coupled to the first terminal of the second resistance selection circuit 154, a second terminal coupled to the second terminal of the second resistance selection circuit 154, and a control terminal coupled to the switch control terminal 158. Switch control terminal 158 may receive a second control signal to turn on or off switch SW 2. The resistor Rn2 may be coupled between the first terminal of the switch SW2 and the second terminal of the switch SW 2. The switches SW1 and SW2 may be MOSFETs, BJTs, or other types of transistors. The resistances Rp2, Rn2 may be variable resistances. The resistors Rp1 and Rn1 may have substantially the same resistance, and the resistors Rp2 and Rn2 may have substantially the same resistance. In some embodiments, the resistor Rp1 and the first resistor selection circuit 152 may be switched, i.e., a first terminal of the resistor Rp1 may be coupled to the signal terminal 151, a second terminal of the resistor Rp1 may be coupled to the first terminal of the first resistor selection circuit 152, and a second terminal of the first resistor selection circuit 152 may be coupled to the first input terminal of the operational amplifier OP. Similarly, the resistor Rn1 and the second resistor selection circuit 154 may swap positions, i.e., a first terminal of the resistor Rn1 may be coupled to the signal terminal 153, a second terminal of the resistor Rn1 may be coupled to a first terminal of the second resistor selection circuit 154, and a second terminal of the second resistor selection circuit 154 may be coupled to a second input terminal of the operational amplifier OP.

Regarding the difference between the reference signal VBG2 and the voltage signal VCC1, the first resistance selection circuit 152 and the second resistance selection circuit 154 may be used to adjust the output voltage Vo and/or the rate of change of the bias current Ibias. Specifically, switches SW1 and SW2 can be turned on or off together to switch the rate of change of the output voltage Vo and/or the bias current Ibias. The output voltage Vo can be expressed by equation 6:

vo k1 (VBG2-VCC1) formula 6

Wherein VBG2 is a reference signal independent of the variation of the supply voltage Vsource;

VCC1 is a voltage signal;

when switch SW1 and switch SW2 are closed,

k1＝Res_RF/(Res_Rp1+Res_Rp2)＝Res_RF/(Res_Rn1+Res_Rn2)；

when switch SW1 and switch SW2 are open,

k1 ═ Res _ RF/Res _ Rp1 ═ Res _ RF/Res _ Rn 1; and

res _ RF, Res _ Rp1, Res _ Rn1, Res _ Rp2 and Res _ Rn2 are resistance values of resistors RF, Rp1, Rn1, Rp2 and Rn2 respectively.

The output voltage Vo can be determined by the difference (VBG2-VCC1) and the slope k 1. Since the reference signal VBG2 is independent of the variation of the source voltage Vsource, and the voltage signal VCC1 is positively correlated to the source voltage Vsource, an increase in the source voltage Vsource will decrease the difference (VBG2-VCC1), thereby decreasing the output voltage Vo; a decrease in the supply voltage Vsource will increase the difference (VBG2-VCC1) and thus increase the output voltage Vo. In this way, variations in the supply voltage Vsource may be compensated for to provide a substantially fixed supply current Icc to the amplifying cell 11.

Referring to fig. 3, the first inverse slope of the line segment 140 and the second inverse slope of the line segment 142 may be implemented by the first resistance selection circuit 152 and the second resistance selection circuit 154 in the variable current source 1200. When the power voltage Vsource is less than the threshold value, the switch SW1 may be turned off to electrically disconnect the first terminal of the switch SW1 from the second terminal of the switch SW1, and the switch SW2 may be turned off to electrically disconnect the first terminal of the switch SW2 from the second terminal of the switch SW2, so that the total resistance values of the resistor Rp1 and the resistor Rp2 (Res _ Rp1+ Res _ Rp2) and the total resistance values of the resistor Rn1 and the resistor Rn2 (Res _ Rn1+ Res _ Rn2) may be used to generate a relatively gentle slope k1, such as the first inverse slope of the segment 140. When the source voltage Vsource exceeds the threshold value, the switch SW1 can be turned on to electrically connect the first terminal of the switch SW1 with the second terminal of the switch SW1, and the switch SW2 can be turned on to electrically connect the first terminal of the switch SW2 with the second terminal of the switch SW2, so that the resistance Res _ Rp1 of the resistor Rp1 and the resistance Res _ Rn1 of the resistor Rn1 can be used to generate a steeper slope k1, such as a second inverse slope of the segment 142. In some embodiments, a line segment with a single inverse slope may be used to model the bias current Ibias, and the first and second

resistance selection circuits

152, 154 may be removed from the variable current source 1200. In some embodiments, the first resistance selection circuit 152, the second resistance selection circuit 154, and the resistances Rp1, Rn1 may be removable from the variable current source 1200 and may be moved to an external circuit outside of the variable current source 1200.

The variable current source 1200 is not limited to providing the bias current Ibias negatively related to the power supply voltage Vsource, but can provide the bias current Ibias positively related to the power supply voltage Vsource by swapping the position of the first resistor selection circuit 152 and the resistor Rp1 with the position of the second resistor selection circuit 154 and the resistor Rn 1. Specifically, the first resistor selection circuit 152 and the resistor Rp1 may be coupled between the signal terminal 153 and the second input terminal of the operational amplifier OP, and the second resistor selection circuit 154 and the resistor Rn1 may be coupled between the signal terminal 151 and the first input terminal of the operational amplifier OP. In such an arrangement, the variable current source 1200 may generate a bias current Ibias that is positively correlated to the supply voltage Vsource.

In addition, the variable current source 1200 is not limited to compensating for a change in the power supply voltage, but may also be used to compensate for a change in temperature and a change in the power of a signal. Fig. 5 is a schematic diagram of another variable current source 1200 in fig. 1. The variable current source 1200 may include

signal terminals

151, 153, a reference potential terminal 155, an operational amplifier OP, a first resistor selection circuit 152, a second resistor selection circuit 154, resistors Rp1, Rn1, RF1, a voltage-to-current converter 156,

switch control terminals

157, 158, resistors Rp3 to Rp6, Rn3 to Rn6, signal terminals 1601 to 1607, and a reference potential terminal 1608. The variable current source 1200 may generate a bias current Ibias to compensate for a variation of a power supply voltage, a power variation of an input signal or an output signal, an ambient temperature (ambient temperature) variation, and/or a temperature variation of the amplifying unit 11. The operational amplifier OP, the first resistor selection circuit 152, the second resistor selection circuit 154, and the resistors Rp1, Rn1, RF1 are the same as those in fig. 4, and the related description is provided in the previous paragraphs and will not be repeated herein. In some embodiments, the resistance value of one of the resistors Rn1, Rn3, Rn4, Rn5, Rn6, or any combination thereof, may be adjusted to selectively remove the resistor RF1 from the variable current source 1200.

The resistor Rp3 may include a first terminal coupled to the signal terminal 1601 for receiving the power signal Vdet2, and a second terminal coupled to a first input terminal of the operational amplifier OP. The resistor Rn3 may include a first terminal coupled to the signal terminal 1602 for receiving the reference signal Vdet02 and a second terminal coupled to a second input terminal of the operational amplifier OP. The power signal Vdet2 may represent the power of the input signal S1 or the output signal S2. The reference signal Vdet02 may be a reference voltage, and the reference signal Vdet02 may be substantially fixed with respect to power variations of the input signal S1 or the output signal S2.

The resistor Rp4 may include a first terminal coupled to the signal terminal 1603 for receiving the temperature signal VPTAT2, and a second terminal coupled to a first input terminal of the operational amplifier OP. The resistor Rn4 may include a first terminal coupled to the signal terminal 1604 for receiving the reference signal VBG3, and a second terminal coupled to a second input terminal of the operational amplifier OP. The temperature signal VPTAT2 may be a Proportional To Absolute Temperature (PTAT) signal. In some embodiments, a CTAT (complementary to absolute temperature) signal may also be used for temperature compensation. In an example using a CTAT signal, a first terminal of the resistor Rp4 may receive the reference signal VBG3 via the signal terminal 1603, and a first terminal of the resistor Rn4 may receive the CTAT signal via the signal terminal 1604. The reference signal VBG3 may be a bandgap reference voltage, the reference signal VBG3 may be substantially constant with respect to temperature variations, and the reference signal VBG3 may be substantially the same as the reference signal VBG 2. In some embodiments, the temperature signal VPTAT2 and the reference signal VBG3 may be generated by circuitry of an Integrated Circuit (IC) disposed on the same die.

The resistor Rp5 may include a first terminal coupled to the signal terminal 1605 for receiving the temperature signal VD0, and a second terminal coupled to a first input terminal of the operational amplifier OP. The resistor Rn5 may include a first terminal coupled to the signal terminal 1606 for receiving the temperature signal Vat, and a second terminal coupled to a second input terminal of the operational amplifier OP. The temperature signal VD0 may represent the temperature on the IC containing the amplification unit 11 for indicating the ambient temperature. The temperature signal Vat may represent the temperature of a location near the amplifying unit 11 for indicating the temperature of the amplifying unit 11. In some embodiments, the temperature signal Vat and the temperature signal VD0 may be generated by a temperature detection circuit of the IC disposed on the same die. In other embodiments, the temperature signals Vat and VD0 can be generated by temperature detection circuits of the IC respectively disposed on different dies. Specifically, the temperature detecting circuit for generating the temperature signal Vat and the amplifying unit 11 may be disposed on the same die, and the temperature detecting circuit for generating the temperature signal VD0 may be disposed on another die and away from the amplifying unit 11.

The resistor Rp6 may include a first terminal coupled to the signal terminal 1607 for receiving the reference signal Vr5, and a second terminal coupled to a first input terminal of the operational amplifier OP. The resistor Rn6 may include a first terminal coupled to the reference potential terminal 1608 for receiving the reference potential Vref5, and a second terminal coupled to a second input terminal of the operational amplifier OP. The reference signal Vr5 may be a reference voltage, and the reference signal Vr5 may be substantially constant with respect to a variation of the power source voltage Vsource.

The resistors Rp 3-Rp 6 and Rn 3-Rn 6 can be variable resistors. The resistances Rp3 and Rn3 may have substantially the same resistance, the resistances Rp4 and Rn4 may have substantially the same resistance, the resistances Rp5 and Rn5 may have substantially the same resistance, and the resistances Rp6 and Rn6 may have substantially the same resistance. The output voltage Vo can be expressed by equation 7:

vo-k 1 (VBG2-VCC1) + k2(Vdet2-Vdet02) + k3(VPTAT2-VBG3) + k4(Vr5-Vref5) + k5(VD0-Vat) formula 7

VCC1 is a voltage signal;

vdet2 is a power signal;

vdet02 is a reference signal independent of power variations of the input signal S1 or the output signal S2;

VPTAT2 is a temperature signal;

VBG3 is a reference signal, independent of temperature variations;

vr5 is a reference signal independent of the variation of the supply voltage Vsource;

vref5 is a reference potential;

VD0 is a temperature signal;

vat is a temperature signal;

when the switch SW1 and the switch SW2 are turned off, k1 ═ Res _ RF/(Res _ Rp1+ Res _ Rp2) ═ Res _ Rp

Res_RF/(Res_Rn1+Res_Rn2)；

When the switch SW1 and the switch SW2 are turned on, k1 ═ Res _ RF/Res _ Rp1 ═ Res _ RF/Res _ Rn 1; and

k2＝Res_RF/Res_Rp3＝Res_RF/Res_Rn3；

k3＝Res_RF/Res_Rp4＝Res_RF/Res_Rn4；

k4＝Res_RF/Res_Rp6＝Res_RF/Res_Rn6；

k5 ═ Res _ RF/Res _ Rp5 ═ Res _ RF/Res _ Rn 5; and

res _ RF, Res _ Rp1 to Res _ Rp6, Res _ Rn1 to Res _ Rn6 are resistance values of the resistors RF, Rp1 to Rp6, and Rn1 to Rn6, respectively.

The output voltage Vo can be determined by the difference (VBG2-VCC1) and slope k1, the difference (Vdet2-Vdet02) and slope k2, the difference (VPTAT2-VBG3) and slope k3, the difference (Vr5-Vref5) and slope k4 and the difference (VD0-Vat) and slope k 5. The difference (VBG2-VCC1) and the slope k1 are described in the previous paragraphs, and are not described herein again.

The linearity of the amplifying unit 11 can be changed according to the power of the input signal S1 or the output signal S2, and the power of the input signal S1 or the output signal S2 is estimated by the power signal Vdet 2. The difference (Vdet2-Vdet02) may represent the amount of power change and may be used to compensate for the power change. The output terminal of the operational amplifier OP can also output an output voltage Vo according to the power signal Vdet2 and the reference signal Vdet 02. Therefore, the bias module 12 can adjust the bias current Ibias according to the power of the input signal S1 or the power of the output signal S2. In some embodiments, the bias current Ibias may be increased when the power of the input signal S1 or the output signal S2 is increased; when the power of the input signal S1 or the output signal S2 is reduced, the bias current Ibias can be reduced, thereby maintaining the linearity of the amplifying unit 11 and improving the efficiency of the amplifying unit 11.

The gain of the amplification unit 11 may vary with the ambient temperature, which is estimated from the temperature signal VPTAT 2. Specifically, the gain of the amplifying unit 11 may decrease as the ambient temperature increases, and increase as the ambient temperature decreases. The difference (VPTAT2-VBG3) may represent an amount of ambient temperature change and may be used to compensate for the ambient temperature change. The output terminal of the operational amplifier OP can also output the output voltage Vo according to the temperature signal VPTAT2 and the reference signal VBG 3. Therefore, the bias module 12 can adjust the bias current Ibias and maintain the gain of the amplifying unit 11 within a predetermined gain range, for example ± 2dB of the specific gain of the amplifying unit 11. For example, the gain of the amplifying unit 11 may be adjusted to 28dB at a high temperature, and the gain of the amplifying unit 11 may be adjusted to 32dB at a low temperature, so as to maintain the gain of the amplifying unit 11 within a range of 30dB ± 2dB when the temperature varies.

The gain of the amplifying unit 11 may vary with the temperature of the amplifying unit 11, and the temperature of the amplifying unit 11 is estimated by the temperature signal Vat. For example, the temperature of the amplification unit 11 may increase with operating time, resulting in a decrease in gain. The difference (VD0-Vat) may represent the amount of change between the ambient temperature and the temperature of the amplifying unit and may be used to compensate for the temperature change of the amplifying unit 11. The output terminal of the operational amplifier OP can also output the output voltage Vo according to the temperature signal VD0 and the temperature signal Vat. Therefore, the bias module 12 can adjust the bias current Ibias and maintain the gain of the amplifying unit 11 within a predetermined gain range, such as ± 0.2dB of the specific gain of the amplifying unit 11. For example, after the amplifying unit 11 is operated for a period of time, the temperature of the amplifying unit 11 gradually increases, and the gain of the amplifying unit 11 can be adjusted to 29.8dB or 30.2dB, so as to maintain the gain of the amplifying unit 11 within a range of 30dB ± 0.2 dB.

The difference (Vr5-Vref5) may represent a basic value for generating the bias current Ibias, which may be used to operate the amplifying unit 11 at a proper operating point (operating point), for example. The output terminal of the operational amplifier OP can also output the output voltage Vo according to the reference signal Vr5 and the reference potential Vref 5. The bias module 12 can adjust the bias current Ibias. In some embodiments, the signal terminal 1607, the reference potential terminal 1608, and the resistors Rp6 and Rn6 may be removed from the variable current source 1200. The basic value of the bias current Ibias may be provided by other bias current generating circuits.

Although in fig. 5, the slopes k2, k3, k4 and k5 are implemented by using only one slope value, the slopes k2, k3, k4 and k5 can also be implemented by using a circuit configuration similar to the first resistance selection circuit 152 and the second resistance selection circuit 154 in fig. 4 to realize 2 or more slope values.

The variable current source 1200 of fig. 4 and 5 can generate a bias current Ibias to compensate for variations in the power supply voltage, power variations of the input/output signal, ambient temperature variations, and/or temperature variations of the amplifying unit, thereby improving the performance of the amplifier device 2.

In addition, in some embodiments, in addition to using the same circuit configuration as the variable current source 1200 of fig. 5, the variable current source 1200 can be changed according to practical applications and design requirements, so as to compensate for one of the power variation of the input/output signal, the ambient temperature variation, or the temperature variation of the amplifying unit, or the selected combination of the foregoing items, besides the variation of the power supply voltage. In some embodiments, the first resistance selection circuit 152, the second resistance selection circuit 154, and the resistances Rp1, Rp3 to Rp6, Rn1, Rn3 to Rn6 may be removed from the variable current source 1200 and may be moved to an external circuit outside the variable current source 1200.

Fig. 6 is a schematic diagram of another amplifier device 2 according to an embodiment of the invention. The bias module 12 may include a variable current source 1200 and a transistor 1201. The transistor 1201 may include a first terminal coupled to the bias voltage source 190, a second terminal coupled to the variable current source 1200, and a third terminal coupled to the second terminal of the amplifying unit 11. The bias voltage source 190 may receive a supply voltage V1. The variable current source 1200 may be implemented by the embodiments of fig. 4 and 5. In some embodiments, the transistor 1201 may be a MOSFET, BJT, or other kind of transistor.

Fig. 7 is a schematic diagram of another amplifier device 2 according to an embodiment of the invention. The bias module 12 may include a transistor 1201, a variable current source 1200, a resistor 1203, and

diodes

1204, 1205. The arrangement of the transistor 1201 and the variable current source 1200 is the same as that in fig. 6, and thus, the description thereof is omitted. The resistor 1203 may include a first terminal coupled to the variable current source 1200 and a second terminal coupled to the second terminal of the transistor 1201. The diode 1204 may include a first terminal coupled to the second terminal of the resistor 1203, and a second terminal. The diode 1205 may include a first terminal coupled to the second terminal of the diode 1204, and a second terminal coupled to the reference potential terminal 30. The reference potential terminal 30 may receive a reference potential Vref 5. In some embodiments, the

diodes

1204, 1205 may be diode connected (dioded connected) transistors.

Fig. 8 is a schematic diagram of another amplifier device 2 according to an embodiment of the invention. The bias module 12 may include a transistor 1201, a variable current source 1200, a resistor 1203, a transistor 1206, and a resistor 1207. The arrangement of the transistor 1201, the variable current source 1200 and the resistor 1203 is the same as that shown in fig. 7, and the description thereof is omitted. The resistor 1207 may include a first terminal and a second terminal coupled to the third terminal of the transistor 1201. The transistor 1206 may include a first terminal coupled to the second terminal of the resistor 1203, a second terminal coupled to the first terminal of the resistor 1207, and a third terminal coupled to the reference potential terminal 30. The reference potential terminal 30 may receive a reference potential Vref 5. In some embodiments, the transistor 1206 may be a MOSFET, a BJT, or other kind of transistor.

The amplifier device 2 of fig. 1, 6 to 8 uses the variable current source 1200 of fig. 4 and 5 to generate the bias current Ibias to compensate for the variation of the power supply voltage, the power variation of the input signal or the output signal, the ambient temperature variation and/or the temperature variation of the amplifying unit, thereby improving the performance of the amplifier device 2.

The amplifier device in the embodiment of the invention can adjust the bias current of the bias module according to various factors, and can perform power supply voltage compensation, signal power compensation, environment temperature compensation and/or temperature compensation of the amplifying unit on the amplifier device, thereby improving the performance of the amplifier device.

The above description is only a preferred embodiment of the present invention, and all equivalent changes and modifications made within the scope of the claims of the present invention should be covered by the present invention.

Claims

1. An amplifier device, comprising:

an amplifying unit having a first terminal coupled to a voltage source for receiving a power voltage, a second terminal for receiving an input signal, and a third terminal coupled to a first reference potential terminal for receiving a first reference potential, wherein the first terminal of the amplifying unit is configured to output an output signal amplified by the amplifying unit; and

a bias module, coupled to the second end of the amplifying unit, for receiving a voltage signal to provide a bias current to the amplifying unit, wherein the voltage signal is a variable voltage;

wherein a supply current flows into the amplifying unit, and the supply current is adjusted according to the voltage signal to maintain the supply current within a predetermined range.

2. The amplifier apparatus of claim 1, wherein:

the bias module is used for providing the bias current according to a first inverse slope, a second inverse slope or the first inverse slope and the second inverse slope;

wherein the voltage signal is substantially positively correlated to the power voltage, and the first inverse slope and the second inverse slope are negatively correlated to the voltage signal.

3. The amplifier apparatus of claim 1, wherein the bias module comprises a variable current source.

4. The amplifier apparatus of claim 3 wherein the variable current source comprises a variable resistor.

5. The amplifier apparatus of claim 3, wherein the variable current source comprises:

an operational amplifier including a first input terminal coupled to a first signal terminal and configured to receive a first reference signal, a second input terminal coupled to a second signal terminal and configured to receive the voltage signal, and an output terminal configured to output an output voltage;

a first resistor having a first end coupled to the second input end of the operational amplifier and a second end coupled to the output end of the operational amplifier; and

a voltage-to-current converter, including a first terminal coupled to the output terminal of the operational amplifier, and a second terminal coupled to the second terminal of the amplifying unit, for converting the output voltage into the bias current.

6. The amplifier apparatus of claim 5, wherein the variable current source further comprises:

a second resistor having a first end coupled to the first signal end and a second end coupled to the first input end of the operational amplifier; and

a third resistor having a first end coupled to the second signal end and a second end coupled to the second input end of the operational amplifier.

7. The amplifier apparatus of claim 6, wherein the second resistor and the third resistor are variable resistors.

8. The amplifier apparatus of claim 6, wherein the variable current source further comprises:

a first resistor selection circuit, including a first terminal coupled to the first signal terminal, and a second terminal coupled to the first terminal of the second resistor; and

the second resistor selection circuit comprises a first end coupled to the second signal end and a second end coupled to the first end of the third resistor.

9. The amplifier apparatus of claim 8, wherein:

the first resistance selection circuit includes:

a first switch, including a first terminal coupled to the first terminal of the first resistor selection circuit, a second terminal coupled to the second terminal of the first resistor selection circuit, and a control terminal; and

a fourth resistor coupled between the first end of the first switch and the second end of the first switch; and

the second resistance selection circuit includes:

a second switch, including a first terminal coupled to the first terminal of the second resistor selection circuit, a second terminal coupled to the second terminal of the second resistor selection circuit, and a control terminal; and

a fifth resistor coupled between the first end of the second switch and the second end of the second switch.

10. The amplifier apparatus of claim 6, wherein the variable current source further comprises:

a sixth resistor having a first terminal coupled to a third signal terminal for receiving a power signal, and a second terminal coupled to the first input terminal of the operational amplifier; and

a seventh resistor having a first end coupled to a fourth signal end for receiving a second reference signal, and a second end coupled to the second input end of the operational amplifier;

wherein the second reference signal is a fixed voltage independent of the power variation of the input signal or the output signal; and

the output terminal of the operational amplifier is further configured to output the output voltage according to the power signal and the second reference signal.

11. The amplifier apparatus of claim 6, wherein the variable current source further comprises:

an eighth resistor having a first end coupled to a fifth signal end for receiving a first temperature signal, and a second end coupled to the first input end of the operational amplifier; and

a ninth resistor having a first end coupled to a sixth signal end for receiving a third reference signal, and a second end coupled to the second input end of the operational amplifier;

wherein the third reference signal is a fixed voltage independent of temperature variation; and

the output terminal of the operational amplifier is further configured to output the output voltage according to the first temperature signal and the third reference signal.

12. The amplifier apparatus of claim 6, wherein the variable current source further comprises:

a tenth resistor having a first end coupled to a seventh signal end for receiving a second temperature signal, and a second end coupled to the first input end of the operational amplifier; and

an eleventh resistor having a first end coupled to an eighth signal end for receiving a third temperature signal, and a second end coupled to the second input end of the operational amplifier;

the output end of the operational amplifier is further used for outputting the output voltage according to the second temperature signal and the third temperature signal.

13. The amplifier apparatus of claim 6, wherein the variable current source further comprises:

a twelfth resistor having a first end coupled to a ninth signal end for receiving a fourth reference signal, and a second end coupled to the first input end of the operational amplifier; and

a thirteenth resistor having a first terminal coupled to a second reference potential terminal for receiving a second reference potential, and a second terminal coupled to the second input terminal of the operational amplifier;

wherein the fourth reference signal is a fixed voltage independent of the voltage variation of the power supply voltage; and

the output terminal of the operational amplifier is further configured to output the output voltage according to the fourth reference signal and the second reference potential.

14. The amplifier apparatus of claim 6, wherein the variable current source further comprises a fourteenth resistor having a first terminal coupled to the first terminal of the first resistor and a second terminal coupled to a third reference potential terminal.

15. The amplifier apparatus of claim 5, wherein said first input terminal of said operational amplifier is a forward terminal and said second input terminal of said operational amplifier is an inverting terminal.

16. The amplifier apparatus of claim 5 wherein said operational amplifier is an adder.

17. The amplifier apparatus of claim 3, wherein the bias module further comprises a first transistor comprising a first terminal coupled to a bias voltage source, a second terminal coupled to the variable current source, and a third terminal coupled to the second terminal of the amplifying cell.

18. The amplifier apparatus of claim 17, wherein the bias module further comprises:

a fifteenth resistor having a first terminal coupled to the variable current source and a second terminal coupled to the second terminal of the first transistor;

a first diode having a first end coupled to the second end of the fifteenth resistor and a second end; and

a second diode having a first terminal coupled to the second terminal of the first diode and a second terminal coupled to a fourth reference potential terminal.

19. The amplifier apparatus of claim 17, wherein the bias module further comprises:

a sixteenth resistor having a first terminal coupled to the variable current source and a second terminal coupled to the second terminal of the first transistor;

a seventeenth resistor having a first end and a second end coupled to the third end of the first transistor; and

a second transistor having a first terminal coupled to the second terminal of the sixteenth resistor, a second terminal coupled to the first terminal of the seventeenth resistor, and a third terminal coupled to a fifth reference potential terminal.

20. The amplifier apparatus of claim 1, wherein the amplifying unit is a power amplifier.