Circuit for controlling transient power consumption of charge pump by adjusting frequency of oscillator and control method

Abstract

The invention provides a circuit for controlling transient power consumption of a charge pump by adjusting the frequency of an oscillator and a control method. The circuit comprises the oscillator and the charge pump, the input end of the oscillator comprises a reference voltage input end for acquiring a reference voltage; the working clock frequency input end is used for acquiring a working clock frequency control signal; the oscillator outputs a corresponding work clock signal according to the reference voltage and the work clock frequency control signal; the input end of the charge pump is electrically connected with the output end of the oscillator to obtain a working clock signal; wherein in different working stages of the charge pump, a preset reference voltage and a preset working clock frequency control signal are respectively provided for the oscillator, so that the oscillator is controlled to output a corresponding working clock signal to the charge pump. The working frequency of the oscillator is changed by changing the current of the oscillator, and the transient power consumption of the charge pump is changed by controlling the working frequencies of different charge pumps.

Description

Technical Field

[0001] The present invention relates to the field of electronic circuits, and in particular to a circuit and a control method for regulating an oscillator frequency to control the transient power consumption of a charge pump. Background Art

[0002] In recent years, with the increasing application of passive radio frequency identification (RFID) technology, the requirements for the identification distance of electronic tags have become increasingly stringent. However, the power consumption of tag chips is the most significant factor affecting the reading distance of electronic tags, resulting in the need for ever-lower power consumption for tag chips. EEPROM, as the carrier for storing information in RFID tags, is one of the essential core circuits of RFID tag chips. Its erase and write power consumption is the primary contributor to the tag chip's power consumption. EEPROM circuits require a relatively high voltage (15V) when erasing and writing information. To enable EEPROM memory to be erased and written at a low power supply voltage, a charge pump circuit is essential. A charge pump circuit utilizes the ability of capacitors to accumulate charge to generate an output voltage higher than the power supply voltage. Reducing the transient power consumption of the charge pump and improving its efficiency can effectively reduce the overall memory power consumption and write distance.

[0003] In order to ensure the driving capability of the charge pump, the common charge pump operating frequency on the market maintains the same frequency during the charge pump startup, ramp-up, and stabilization stages, and the frequency will change with the manufacturing process. Due to the low power efficiency of the charge pump during the ramp-up stage, large transient power consumption will occur. Summary of the Invention

[0004] In view of the defects in the prior art, the object of the present invention is to provide a circuit and a control method for adjusting the oscillator frequency to control the transient power consumption of a charge pump.

[0005] According to the present invention, a circuit for regulating the frequency of an oscillator to control the transient power consumption of a charge pump includes: an oscillator and a charge pump;

[0006] The input terminal of the oscillator includes:

[0007] Reference voltage input terminal, to obtain reference voltage;

[0008] Working clock frequency input terminal, obtaining working clock frequency control signal;

[0009] The oscillator outputs a corresponding working clock signal according to the reference voltage and the working clock frequency control signal;

[0010] The input end of the charge pump is electrically connected to the output end of the oscillator to obtain the working clock signal;

[0011] In different working stages of the charge pump, a preset reference voltage and a preset working clock frequency control signal are respectively provided to the oscillator, thereby controlling the oscillator to output a corresponding working clock signal to the charge pump.

[0012] Furthermore, it also includes a power management module;

[0013] The output end of the power management module includes:

[0014] a reference voltage output terminal, electrically connected to the reference voltage input terminal, and the reference voltage output terminal outputs the reference voltage;

[0015] The working clock frequency output terminal is electrically connected to the working clock frequency input terminal, and the working clock frequency output terminal outputs the working clock frequency control signal.

[0016] Further, the oscillator includes a first enable signal input terminal, and the charge pump includes a second enable signal input terminal;

[0017] The input end of the power management module obtains the induced voltage of the RFID tag antenna, and the output end of the power management unit also includes:

[0018] an enable signal output terminal, electrically connected to the first enable signal input terminal and the second enable signal input terminal respectively;

[0019] The power management module generates an enable signal according to its internal circuit.

[0020] Furthermore, the different working phases of the charge pump include: a startup phase, a stable phase, and at least one transition phase between the startup phase and the stable phase.

[0021] Furthermore, the transition phase is a climbing phase.

[0022] Furthermore, when the voltage output by the charge pump is less than or equal to the first reference voltage, the charge pump operates in the startup phase;

[0023] When the voltage output by the charge pump is greater than the first reference voltage and less than or equal to the second reference voltage, the charge pump operates in the climbing phase;

[0024] When the voltage output by the charge pump is greater than the second reference voltage, the charge pump operates in the stable phase.

[0025] Furthermore, in the startup phase, the operating clock frequency control signal is a first operating clock frequency control signal, and the charge pump operates at the first operating clock frequency;

[0026] In the ramp-up phase, the operating clock frequency control signal is a second operating clock frequency control signal, and the charge pump operates at the second operating clock frequency;

[0027] In the stable phase, the operating clock frequency control signal is a third operating clock frequency control signal, and the charge pump operates at the third operating clock frequency.

[0028] Furthermore, the second operating clock frequency is greater than the first operating clock frequency and greater than the third operating clock frequency.

[0029] Furthermore, the reference voltages include, arranged in order from small to large: a first reference voltage, ..., and an n-1th reference voltage, where n is the total number of different working stages and n is a natural number ≥ 3, corresponding one-to-one to the startup stage and the transition stage in sequence;

[0030] When the voltage output by the charge pump is less than or equal to the first reference voltage, the charge pump operates in the startup phase;

[0031] When the voltage output by the charge pump is greater than the first reference voltage and less than or equal to the n-1th reference voltage, the charge pump operates in the transition stage, and the number of the transition stages is n-2;

[0032] When the voltage output by the charge pump is greater than the (n-1)th reference voltage, the charge pump operates in the stable phase.

[0033] Furthermore, the working clock frequency control signal includes a first working clock frequency control signal, a second working clock frequency control signal, ... and an nth working clock frequency control signal, where n is the total number of different working stages and n is a natural number ≥3;

[0034] Each of the working clock frequency control signals corresponds to a working phase, and the oscillator outputs the corresponding working clock frequency to the charge pump according to the working clock frequency control signal.

[0035] Furthermore, when n is greater than 3, the first working clock frequency is less than the second working clock frequency, ..., the n-2th working clock frequency is less than the n-1th working clock frequency, and the n-1th working clock frequency is greater than the nth working clock frequency.

[0036] According to the present invention, a control method for a circuit for adjusting an oscillator frequency to control transient power consumption of a charge pump includes:

[0037] Step 1: Detecting the voltage value of the charge pump output voltage and determining whether the voltage value is greater than a reference voltage corresponding to the current working stage;

[0038] If the judgment result is no, the operating clock frequency control signal corresponding to the current operating phase is input to the oscillator; if the judgment result is yes, the operating clock frequency control signal corresponding to the next operating phase is input to the oscillator.

[0039] Furthermore, it also includes:

[0040] Step 0: After obtaining the induced voltage of the RFID tag antenna, the power management module generates an enable signal based on its internal circuit, provides the enable signal to the charge pump and oscillator, and drives the charge pump and oscillator to work.

[0041] Furthermore, it also includes:

[0042] Step 2: Repeat step 1 until the current working stage is the stable stage and no further judgment is made until the enable signal ends, the stable stage ends, and the charge pump and oscillator stop working.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] The present invention changes the operating frequency of the oscillator by changing the size of the oscillator current, adopts different oscillator operating frequencies to boost the charge pump during the charge pump startup, climbing and stabilization stages, and changes the transient power consumption of the charge pump by controlling different charge pump operating frequencies.

[0045] The oscillator's operating current can be controlled using registers in the digital module, facilitating post-tapeout adjustments. The oscillator's operating frequency is solely dependent on the current level; accurate current adjustment ensures that the oscillator's operating frequency remains constant throughout the manufacturing process. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Other features, objects and advantages of the present invention will become more apparent upon reading the detailed description of non-limiting embodiments with reference to the following drawings:

[0047] Figure 1 This is the working principle diagram of the reader and RFID tag;

[0048] Figure 2 is a schematic diagram of the power management module;

[0049] Figure 3 is a schematic diagram of an oscillator;

[0050] Figure 4 is a schematic diagram of a charge pump;

[0051] Figure 5 It is a workflow diagram of the present invention;

[0052] Figure 6This is a timing control diagram of the present invention. DETAILED DESCRIPTION

[0053] The present invention will be described in detail below with reference to specific embodiments. The following examples will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those skilled in the art, several changes and improvements can be made without departing from the scope of the present invention. These all fall within the scope of protection of the present invention.

[0054] A circuit for regulating the frequency of an oscillator to control the transient power consumption of a charge pump comprises an oscillator, a charge pump and a power management module.

[0055] The inputs to the oscillator include:

[0056] Reference voltage input terminal, used to obtain reference voltage.

[0057] The working clock frequency input terminal is used to obtain the working clock frequency control signal.

[0058] The output terminals of the power management module include:

[0059] The reference voltage output terminal is electrically connected to the reference voltage input terminal of the oscillator and is used to provide a reference voltage.

[0060] The working clock frequency output terminal is electrically connected to the working clock frequency input terminal of the oscillator and is used for providing a working clock frequency control signal.

[0061] The oscillator includes a first enable signal input terminal, and the charge pump includes a second enable signal input terminal. The input terminal of the power management module obtains the induced voltage of the RFID tag antenna, and the output terminal of the power management unit also includes:

[0062] The enable signal output terminal is electrically connected to the first enable signal input terminal and the second enable signal input terminal respectively.

[0063] The power management module generates an enable signal based on its internal circuit.

[0064] The oscillator outputs a corresponding working clock signal according to a reference voltage and a working clock frequency control signal. The input end of the charge pump is electrically connected to the output end of the oscillator to obtain the working clock signal.

[0065] In different working stages of the charge pump, a preset reference voltage and a preset working clock frequency control signal are respectively provided to the oscillator, thereby controlling the oscillator to output a corresponding working clock signal to the charge pump.

[0066] like Figure 1As shown, the reader transmits a high-frequency modulated signal through its antenna L1, generating a high-frequency electromagnetic field. Because the carrier frequency used is 13.56 MHz, its wavelength is many times greater than the distance between the reader antenna L1 and the tag antenna L2. Therefore, this field can be treated as a simple alternating magnetic field. This magnetic field passes through the tag antenna L2 and induces an alternating voltage on L2, namely, the induced voltage U2.

[0067] The induced voltage U2 is rectified and enters Figure 2 The power management module generates a WRE (write enable) signal, VREF_8 (charge pump outputs an 8V reference voltage), VREF_15 (charge pump outputs a 15V reference voltage), and ISOC<2:0> (a control signal for changing the operating clock frequency of the charge pump oscillator) when the RFID chip is powered on.

[0068] like Figure 3 As shown, the WRE (write enable) signal, ISOC<2:0> (used to change the working clock frequency of the charge pump oscillator), VPP_8 (charge pump output is lower than 8V voltage), and VPP_15 (charge pump output is lower than 15V voltage) are input to the charge pump, and the output PMP_CLK (the working clock used by the charge pump to boost voltage) is output.

[0069] like Figure 4 As shown, the WRE (write enable) signal and PMP_CLK (the working clock used by the charge pump to boost the voltage) are input to the charge pump, and the outputs are VPP_8 (charge pump output voltage lower than 8V), VPP_15 (charge pump output voltage lower than 15V), and VPP (charge pump output voltage, the voltage required for EEPROM erasing).

[0070] In this embodiment, the different working phases of the charge pump include: a startup phase, a stable phase, and at least one transition phase between the startup phase and the stable phase, wherein the transition phase is a ramp-up phase.

[0071] When the voltage output by the charge pump is less than or equal to the first reference voltage, the charge pump operates in a startup phase.

[0072] When the voltage output by the charge pump is greater than the first reference voltage and less than or equal to the second reference voltage, the charge pump operates in the climbing phase.

[0073] When the voltage output by the charge pump is greater than the second reference voltage, the charge pump operates in a stable phase.

[0074] In the startup phase, the operating clock frequency control signal is a first operating clock frequency control signal, and the charge pump operates at the first operating clock frequency.

[0075] In the ramp-up phase, the operating clock frequency control signal is a second operating clock frequency control signal, and the charge pump operates at the second operating clock frequency.

[0076] In the stable phase, the operating clock frequency control signal is the third operating clock frequency control signal, and the charge pump operates at the third operating clock frequency.

[0077] The second operating clock frequency is greater than the first operating clock frequency and greater than the third operating clock frequency.

[0078] The reference voltages include the first reference voltage, ... and the n-1th reference voltage, which are arranged in order from small to large, where n is the total number of different working stages and n is a natural number ≥ 3, and correspond one-to-one to the startup stage and the transition stage.

[0079] When the voltage output by the charge pump is less than or equal to the first reference voltage, the charge pump operates in a startup phase.

[0080] When the voltage output by the charge pump is greater than the first reference voltage and less than or equal to the n-1th reference voltage, the charge pump operates in a transition phase, and the number of transition phases is n-2.

[0081] When the voltage output by the charge pump is greater than the (n-1)th reference voltage, the charge pump operates in a stable phase.

[0082] The specific values ​​of the reference voltages can be adjusted according to actual conditions. In this embodiment, the first reference voltage is 8V±2V, and the second reference voltage is 15V+2V.

[0083] The working clock frequency control signal includes a first working clock frequency control signal, a second working clock frequency control signal, ... and an nth working clock frequency control signal, where n is the total number of different working stages and n is a natural number ≥3.

[0084] Each working clock frequency control signal corresponds to a working phase, and the oscillator outputs the corresponding working clock frequency to the charge pump according to the working clock frequency control signal.

[0085] Furthermore, when n is greater than 3, the first working clock frequency is less than the second working clock frequency, ..., the (n-2)th working clock frequency is less than the (n-1)th working clock frequency, and the (n-1)th working clock frequency is greater than the (n)th working clock frequency.

[0086] like Figure 5 As shown, the present invention also provides a control method for a circuit for adjusting an oscillator frequency to control transient power consumption of a charge pump, comprising:

[0087] Step 0: After obtaining the induced voltage of the RFID tag antenna, the power management module generates an enable signal based on its internal circuit, provides the enable signal to the charge pump and oscillator, and drives the charge pump and oscillator to work.

[0088] Step 1: Detect the output voltage of the charge pump and determine whether the voltage is greater than the reference voltage corresponding to the current working stage;

[0089] If the judgment result is no, the operating clock frequency control signal corresponding to the current operating phase is input to the oscillator; if the judgment result is yes, the operating clock frequency control signal corresponding to the next operating phase is input to the oscillator.

[0090] Step 2: Repeat step 1 until the current working stage is the stable stage and no further judgment is made until the enable signal ends, the stable stage ends, and the charge pump and oscillator stop working.

[0091] like Figure 6 As shown, the RFID chip enters the field, generates WRE, the chip accepts the write instruction, the charge pump is enabled, and the OSC (oscillator) and Charge_Pump (charge pump) work.

[0092] When VPP < 8V, the digital control output OSC <2:0> = value1, PMP_CLK frequency = fre1, and VPP is in the ramp1 stage. When VPP > 8V, the digital control output OSC <2:0> = value2, PMP_CLK frequency = fre2, and VPP is in the ramp2 stage. VPP continues to ramp. When VPP < 15V, the digital control output OSC <2:0> = value2, PMP_CLK frequency = fre2, and VPP is still in the ramp2 stage.

[0093] When VPP>15V, the digital control output OSC<2:0>=value3, PMP_CLK frequency=fre3, VPP is in the stable stage, and VPP maintains Refresh.

[0094] The above describes specific embodiments of the present invention. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art may make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. The embodiments of this application and the features in the embodiments may be combined with each other in any manner unless there is a conflict.

Claims

1. A circuit for regulating the oscillator frequency to control the transient power consumption of a charge pump, characterized in that: include: oscillators and charge pumps; The input terminal of the oscillator includes: Reference voltage input terminal, to obtain reference voltage; Working clock frequency input terminal, obtaining working clock frequency control signal; The oscillator outputs a corresponding working clock signal according to the reference voltage and the working clock frequency control signal; The input end of the charge pump is electrically connected to the output end of the oscillator to obtain the working clock signal; In different working stages of the charge pump, a preset reference voltage and a preset working clock frequency control signal are respectively provided to the oscillator, thereby controlling the oscillator to output a corresponding working clock signal to the charge pump.

2. The circuit for adjusting the oscillator frequency to control the transient power consumption of a charge pump according to claim 1, characterized in that: Also includes a power management module; The output end of the power management module includes: a reference voltage output terminal, electrically connected to the reference voltage input terminal, and the reference voltage output terminal outputs the reference voltage; The working clock frequency output terminal is electrically connected to the working clock frequency input terminal, and the working clock frequency output terminal outputs the working clock frequency control signal.

3. The circuit for adjusting the oscillator frequency to control the transient power consumption of a charge pump according to claim 2, characterized in that: The oscillator includes a first enable signal input terminal, and the charge pump includes a second enable signal input terminal; The input end of the power management module obtains the induced voltage of the RFID tag antenna, and the output end of the power management unit also includes: an enable signal output terminal, electrically connected to the first enable signal input terminal and the second enable signal input terminal respectively; The power management module generates an enable signal according to its internal circuit.

4. The circuit for adjusting the oscillator frequency to control the transient power consumption of a charge pump according to claim 1, wherein: The different working phases of the charge pump include a startup phase, a stable phase, and at least one transition phase between the startup phase and the stable phase.

5. The circuit for adjusting the oscillator frequency to control the transient power consumption of a charge pump according to claim 4, characterized in that: The transition phase is a climbing phase.

6. The circuit for adjusting the oscillator frequency to control the transient power consumption of a charge pump according to claim 5, characterized in that: When the voltage output by the charge pump is less than or equal to the first reference voltage, the charge pump operates in the startup phase; When the voltage output by the charge pump is greater than the first reference voltage and less than or equal to the second reference voltage, the charge pump operates in the climbing phase; When the voltage output by the charge pump is greater than the second reference voltage, the charge pump operates in the stable phase.

7. The circuit for adjusting the oscillator frequency to control the transient power consumption of a charge pump according to claim 5, characterized in that: In the startup phase, the operating clock frequency control signal is a first operating clock frequency control signal, and the charge pump operates at the first operating clock frequency; In the ramp-up phase, the operating clock frequency control signal is a second operating clock frequency control signal, and the charge pump operates at the second operating clock frequency; In the stable phase, the operating clock frequency control signal is a third operating clock frequency control signal, and the charge pump operates at the third operating clock frequency.

8. The circuit for adjusting the oscillator frequency to control the transient power consumption of a charge pump according to claim 7, wherein: The second operating clock frequency is greater than the first operating clock frequency and greater than the third operating clock frequency.

9. The circuit for adjusting the oscillator frequency to control the transient power consumption of a charge pump according to claim 4, characterized in that: The reference voltages include, arranged in descending order: a first reference voltage, ..., and an n-1th reference voltage, where n is the total number of different working stages and n is a natural number ≥ 3, and correspond one-to-one to the startup stage and the transition stage respectively; When the voltage output by the charge pump is less than or equal to the first reference voltage, the charge pump operates in the startup phase; When the voltage output by the charge pump is greater than the first reference voltage and less than or equal to the n-1th reference voltage, the charge pump operates in the transition stage, and the number of the transition stages is n-2; When the voltage output by the charge pump is greater than the (n-1)th reference voltage, the charge pump operates in the stable phase.

10. The circuit for adjusting the oscillator frequency to control the transient power consumption of a charge pump according to claim 4, wherein: The working clock frequency control signal includes a first working clock frequency control signal, a second working clock frequency control signal, ... and an nth working clock frequency control signal, where n is the total number of different working stages and n is a natural number ≥3; Each of the working clock frequency control signals corresponds to a working phase, and the oscillator outputs the corresponding working clock frequency to the charge pump according to the working clock frequency control signal.

11. The circuit for adjusting the oscillator frequency to control the transient power consumption of a charge pump according to claim 10, characterized in that: When n is greater than 3, the first working clock frequency is less than the second working clock frequency, ..., the (n-2)th working clock frequency is less than the (n-1)th working clock frequency, and the (n-1)th working clock frequency is greater than the (n)th working clock frequency.

12. A control method for a circuit for adjusting an oscillator frequency to control transient power consumption of a charge pump according to any one of claims 1 to 11, characterized in that: include: Step 1: Detecting the voltage value of the charge pump output voltage and determining whether the voltage value is greater than a reference voltage corresponding to the current working stage; If the judgment result is negative, inputting a working clock frequency control signal corresponding to the current working stage into the oscillator; If the judgment result is yes, a working clock frequency control signal corresponding to the next working stage is input to the oscillator.

13. The control method of a circuit for adjusting an oscillator frequency to control transient power consumption of a charge pump according to claim 12, characterized in that: Also includes: Step 0: After obtaining the induced voltage of the RFID tag antenna, the power management module generates an enable signal based on its internal circuit, provides the enable signal to the charge pump and oscillator, and drives the charge pump and oscillator to work.

14. The control method of a circuit for adjusting an oscillator frequency to control transient power consumption of a charge pump according to claim 12, wherein: Also includes: Step 2: Repeat step 1 until the current working stage is the stable stage and no further judgment is made until the enable signal ends, the stable stage ends, and the charge pump and oscillator stop working.

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