CN1741375B - Amplifying circuit that can dynamically adjust the supply voltage - Google Patents

Abstract

The invention discloses an amplifying circuit, which can utilize a switched capacitor voltage converter to dynamically adjust the supply voltage of an amplifier according to the output signal or the input signal of the amplifier so as to improve the energy use efficiency of the amplifying circuit. The switched capacitor voltage converter can switch and select the magnitude of the supply voltage. The amplifier circuit further comprises a control device coupled to an input end or an output end of the amplifier for generating a control signal to the switched capacitor voltage converter according to an input signal or an output signal of the amplifier.

Description

Amplifying circuit that can dynamically adjust the supply voltage

technical field

The invention relates to an amplifying circuit, in particular to an amplifying circuit which utilizes a switched capacitor voltage converter to dynamically adjust the supply voltage.

Background technique

Amplifiers are commonly used circuit components, however, typical amplifiers do not use energy efficiently. Generally speaking, the energy provided by the supply voltage cannot and will not be fully used to drive the amplifier to output the required output signal according to the input signal, and a lot of energy will be wasted.

In view of this, the focus of the present invention is to propose an amplifying circuit that can dynamically adjust the supply voltage of the amplifier by using a switched-capacitor voltage converter (switched-capacitorvoltage converter) according to the input or output signal of the amplifier, so as to improve the energy Use efficiency.

Contents of the invention

One of the objectives of the present invention is to provide an amplifying circuit capable of dynamically adjusting the supply voltage, which includes an amplifier and a switched capacitor voltage converter. The switched capacitor voltage converter is coupled to the amplifier and can be used to dynamically adjust a supply voltage of the amplifier according to the output signal or the input signal of the amplifier.

In a preferred embodiment, the switched capacitor voltage converter can switch and select to adjust the magnitude of the supply voltage.

In a preferred embodiment, the amplifying circuit further includes a control device, coupled to an input terminal or an output terminal of the amplifier, for generating a control signal to the switched capacitor voltage converter according to an input or output signal of the amplifier, The switched capacitor voltage converter adjusts the supply voltage accordingly.

Since the switched capacitor voltage converter has many advantages such as simple circuit design, quick response, low cost, low electromagnetic interference (EMI) and high power conversion efficiency, the amplifying circuit of the present invention can dynamically adjust the supply voltage in a short time , to achieve the purpose of improving the power usage efficiency of the amplifying circuit.

Description of drawings

FIG. 1 is a block diagram of a preferred embodiment of the amplifying circuit of the present invention.

FIG. 2 is a circuit diagram of an embodiment of the switched capacitor voltage converter of FIG. 1 .

3A, B and C are simplified circuit diagrams of the switched capacitor voltage converter of FIG. 2 at different gain values.

FIG. 4 is a block diagram of another preferred embodiment of the amplifying circuit of the present invention.

Explanation of reference numbers:

1, 4: Amplifying circuit 10: Amplifier

11, 11a: Switched Capacitor Voltage Converter

12: Control device 121: Peak detector

122: Voltage sensor 123: Gain control unit

Detailed ways

In order to have a further understanding and recognition of the present invention, a detailed description will now be given in conjunction with the accompanying drawings.

FIG. 1 is a block diagram of a preferred embodiment of the amplifying circuit of the present invention. As shown in FIG. 1 , the amplifying circuit 1 includes an amplifier 10 , a switched capacitor voltage converter 11 and a control device 12 . The switched capacitor voltage converter 11 is coupled to the amplifier 10 and can convert a received voltage source V _dd into a supply voltage and send it to the amplifier 10 . If the gain of the switched capacitor voltage converter 11 is G, the supply voltage is G*V _dd , as shown in the figure. The switched capacitor voltage converter 11 can also dynamically adjust its gain G according to a control signal, which will be described in more detail later.

The control device 12 can generate the control signal to the switched capacitor voltage converter 11 according to an output signal of the amplifier 10 . In the embodiment of FIG. 1 , the control device 12 includes a peak detector (peak detector) 121 , a voltage sensor (voltage level sensor) 122 and a gain control unit (gain control unit) 123 . The peak detector 121 is coupled to an output terminal of the amplifier 10 for detecting a peak value of the output voltage of the amplifier 10 . The voltage sensor 122 is coupled to the peak detector 121 and has a plurality of voltage intervals, and selects one of the voltage intervals according to the peak value of the output voltage detected by the peak detector 121 . The gain control unit 123 generates the control signal according to the voltage interval selected by the voltage sensor 122 and sends it to the switched capacitor voltage converter 11 . Wherein, the working principles and hardware implementations of the peak detector 121 , the voltage sensor 122 and the gain control unit 123 are well known to those skilled in the art, and will not be described in detail in this specification.

As mentioned above, the switched capacitor voltage converter 11 dynamically adjusts the gain value according to the control signal to provide different supply voltages. In fact, the switched capacitor voltage converter 11 can have multiple gain values by using a specific coupling configuration of capacitors and switches, which can usually be expressed in the form of M/N, where M and N are integers. By switching the switch, the switched capacitor voltage converter 11 can be switched between these gain values.

FIG. 2 is a circuit diagram of an embodiment of the switched capacitor voltage converter 11 . As shown in Figure 2, the switched capacitor voltage converter 11a includes capacitors C ₁ , C ₂ and switches S ₁ to S ₁₀ , and the input voltage (i.e. the voltage at point X) is V _dd , and the output voltage after conversion (i.e. the voltage at point Y voltage) is G*V _dd , where G is the gain value. In operation, a group of switches _S1 and _S2 are in ON/OFF state according to a first clock signal, while another group of switches _S3 and _S4 are in a state of ON/OFF according to a second clock signal. It is in ON/OFF state, and the two sets of switches will not be turned on at the same time.

The switched capacitor voltage converter 11 a in FIG. 2 has three gain values of 1, 0.5 and −1, and the corresponding gain values can be adjusted by switching the switches S ₅ to S ₁₀ . The corresponding relationship between the switching mode and the gain value is as follows:

(1) If S ₅ , S ₆ and S ₉ are ON, and S ₇ , S ₈ and S ₁₀ are OFF, then Figure 2 can be simplified to the circuit shown in Figure 3A. When S ₁ and S ₂ are turned on (S3 and S4 are disconnected), the voltage of capacitor C ₁ will become V _dd ; and when S ₃ and S ₄ are turned on (S ₁ and S ₂ are disconnected), C ₁ The voltage V _{dd of} will be transferred to the capacitor C ₂ , so that the voltage at point X is V _dd , so the gain value G=1.

(2) If S ₆ , S ₈ and S ₉ are ON, and S ₅ , S ₇ and S ₁₀ are OFF, then Fig. 2 can be simplified to the circuit of Fig. 3B. When S ₁ and S ₂ are turned on, the voltage of C ₁ will become V _dd * (1-G) (that is, the voltage difference between X and Y); and when S ₃ and S ₄ are turned on, the voltage of C ₁ The voltage V _dd *(1-G) will be transferred to C ₂ , so that the voltage at point X is V _dd *G, that is

_Vdd *G＝ _Vdd *(1-G)

From this, it can be deduced that G=0.5.

(3) If S ₅ , S ₇ and S ₁₀ are ON, and S ₆ , S ₈ and S ₉ are OFF, then Fig. 2 can be simplified to the circuit of Fig. 3C. When S ₁ and S ₂ are turned on, the voltage of C ₁ will become V _dd ; and when S ₃ and S ₄ are turned on, the voltage V _dd of C ₁ will be transferred to C ₂ , and the voltage at point X will be -V _dd , so G=-1.

Of course, those skilled in the art can design a corresponding switched capacitor voltage converter according to the required gain value. As long as it is applied, the use of the switched capacitor voltage converter to dynamically adjust the supply voltage of the amplifier does not depart from the spirit and scope of the present invention.

FIG. 4 is a block diagram of another preferred embodiment of the amplifying circuit of the present invention. Compared with the embodiment of FIG. 1, the components included in the amplifying circuit 4 are the same as those of the amplifying circuit 1. The only difference is that the control device 12 in FIG. connected to the input of amplifier 10. In other words, in FIG. 4 , the control device 12 generates a control signal to the switched capacitor voltage converter 11 according to an input signal of the amplifier 10 . Specifically, the peak detector 121 in the control device 12 detects a peak input voltage of the amplifier 10 to be sent to the voltage sensor 122 . The operation of the rest of the amplifying circuit 4 is the same as the aforesaid amplifying circuit 1, and will not be repeated here.

The above description is to illustrate the present invention with preferred embodiments, but not to limit the scope of the present invention. Those skilled in the art can understand that appropriate changes and adjustments will still fall within the protection scope of the claims of the present invention.

Claims (4)

1. An amplifying circuit capable of dynamically adjusting a supply voltage, comprising: an amplifier for receiving an input signal and outputting an output signal through a supply voltage; and a supply voltage adjustment circuit, coupled to the amplifier, for dynamically adjusting the supply voltage of the amplifier according to the input signal or output signal of the amplifier, Wherein the supply voltage adjustment circuit includes a switched capacitor voltage converter, wherein the switched capacitor voltage converter is used to output the supply voltage according to an input voltage, and the switched capacitor voltage converter can switch to select the supply voltage relative to the input voltage gain. 2. The amplifying circuit as claimed in claim 1, wherein the switched capacitor voltage converter further comprises: an input terminal for receiving the input voltage; an output terminal for outputting the supply voltage; a plurality of capacitors, respectively coupled to the input terminal and the output terminal; and a plurality of switches, wherein each of the plurality of switches is directly coupled to at least one of the input terminal, the output terminal or the plurality of capacitors; Wherein, by controlling switching of each of the plurality of switches, the supply voltage has a gain relative to the input voltage. 3. The amplifying circuit as claimed in claim 1, further comprising a control device coupled to the amplifier for generating a control signal to control the supply voltage according to at least one of the input signal and the output signal of the amplifier Adjust the circuit. 4. The amplifying circuit as claimed in claim 3, wherein the control device comprises: a peak detector for detecting a voltage peak of at least one of the input signal and the output signal of the amplifier; a voltage sensor, coupled to the peak detector, for sensing the magnitude of the voltage peak; and A gain control unit outputs the control signal according to the sensing result of the voltage sensor.

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