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CN-122001455-A - Pulse current generation circuit, low-noise frequency demultiplier and satellite receiver

CN122001455ACN 122001455 ACN122001455 ACN 122001455ACN-122001455-A

Abstract

The application provides a pulse current generating circuit, a low-noise frequency demultiplier and a satellite receiver. The circuit comprises a pulse generation module, a current generation module and a current mirror module, wherein the current generation module is respectively and electrically connected with the pulse generation module and the current mirror module, and the current mirror module is used for being electrically connected with the output end of the LDO in the low noise frequency reducer. The current mirror module outputs pulse current according to the first current, and the pulse current is pull-down current connected to the output end of the LDO. The pulse current generating circuit generates and outputs the pull-down pulse current only in the period when the modulation wave needs to be reduced, effectively reduces the invalid current loss without the period, can greatly reduce the average power consumption in the LNB power supply modulation process, and greatly improves the power supply conversion efficiency when the LNB power supply is modulated.

Inventors

  • LIN DASONG

Assignees

  • 深圳市微源半导体股份有限公司

Dates

Publication Date
20260508
Application Date
20260403

Claims (10)

  1. 1. The pulse current generation circuit is characterized by being applied to a low-noise frequency demultiplier, and comprises a pulse generation module, a current generation module and a current mirror module, wherein the current generation module is respectively and electrically connected with the pulse generation module and the current mirror module, and the current mirror module is used for being electrically connected with the output end of an LDO (low-dropout regulator) in the low-noise frequency demultiplier; The current generation module is used for receiving the square wave signal and outputting a first pulse voltage when the square wave signal falls, the current generation module is used for generating a first current according to the first pulse voltage, and the current mirror module is used for outputting a pulse current according to the first current, wherein the pulse current is a pull-down current connected to the output end of the LDO.
  2. 2. The pulsed current generation circuit of claim 1, wherein the pulse generation module comprises a pulse generator electrically coupled to the current generation module for outputting the first pulsed voltage upon a falling edge of the square wave signal.
  3. 3. The pulse current generating circuit according to claim 1, wherein the current generating module comprises an operational amplifier unit and a resistance unit, the operational amplifier unit being electrically connected with the pulse generating module, the resistance unit and the current mirror module, respectively; the operational amplifier unit is used for obtaining an operational amplifier voltage according to the first pulse voltage, and the resistor unit is used for converting the operational amplifier voltage into the first current.
  4. 4. The pulse current generating circuit according to claim 3, wherein the operational amplifier unit comprises a first operational amplifier and a first transistor, a first input terminal of the first operational amplifier is electrically connected to the pulse generating module, a second input terminal of the first operational amplifier is electrically connected to a source terminal of the first transistor and the resistor unit, respectively, an output terminal of the first operational amplifier is electrically connected to a gate terminal of the first transistor, and a drain terminal of the first transistor is electrically connected to the current mirror module.
  5. 5. The pulse current generating circuit according to claim 3, wherein the resistance unit includes a first resistor having a first end electrically connected to the op amp unit and a second end grounded.
  6. 6. The pulsed current generation circuit of claim 1, wherein the current mirror module comprises a first current mirror unit and a second current mirror unit, the first current mirror unit being electrically connected to the second current mirror unit and the current generation module, respectively, the second current mirror unit being for electrical connection with an output of an LDO in the low noise down converter; The first current mirror unit is used for outputting a mirror current according to the first current, and the second current mirror unit is used for outputting the pulse current according to the mirror current.
  7. 7. The pulse current generating circuit according to claim 6, wherein the first current mirror unit comprises a second transistor and a third transistor, a gate of the second transistor is electrically connected to a drain of the second transistor, a gate of the third transistor, and the current generating module, respectively, a source of the second transistor and a source of the third transistor are each configured to be electrically connected to a power supply, and a drain of the third transistor is electrically connected to the second current mirror unit.
  8. 8. The pulse current generating circuit of claim 6, wherein the second current mirror unit comprises a fourth transistor and a fifth transistor, a gate of the fourth transistor is electrically connected to a drain of the fourth transistor, a gate of the fifth transistor, and the first current mirror unit, respectively, a source of the fourth transistor and a source of the fifth transistor are grounded, and a source of the fifth transistor is electrically connected to an output of the LDO in the low noise down converter.
  9. 9. A low noise frequency demultiplier, characterized by comprising a boost circuit, a logic control circuit, an LDO and the pulse current generating circuit of any of claims 1-8, wherein the logic control circuit is electrically connected with the boost circuit and the LDO, respectively, and the LDO is electrically connected with a current mirror module in the pulse current generating circuit.
  10. 10. A satellite receiver comprising the low noise down converter of claim 9.

Description

Pulse current generation circuit, low-noise frequency demultiplier and satellite receiver Technical Field The application belongs to the technical field of power supplies, and particularly relates to a pulse current generating circuit, a low-noise frequency demultiplier and a satellite receiver. Background The LNB (Low Noise Bock downconverter, low noise frequency demultiplier) is the core device of the satellite receiver, and the normal operation of the LNB needs to be matched with a special power framework to realize the functions of voltage boosting, voltage stabilizing and high frequency modulation. The prior LNB power supply framework generally adopts an asynchronous boost DC-DC module to boost the input voltage VIN to 15.2V or 20.2V, and then takes electricity from a boost voltage end through an LDO (Low Dropout Regulator, low dropout linear regulator) to output a high power supply rejection ratio direct current voltage of 14V or 19V, wherein the LNB outputs 14V when a control signal CTRL is 0, and the LNB outputs 19V when the CTRL is 1. In order to realize the function of local oscillation frequency switching or signal source switching in a satellite receiver, a 22KHz modulation square wave needs to be superimposed at the output end of an LDO, and specifically, a controlled modulation wave with the amplitude of 700mV, the duty ratio of 50% and the edge slope meeting the requirements is obtained at the LNB end by inputting a 22KHz square wave with the duty ratio of 50% to the modulation end TONE. As the capacitance of the LNB output end is 300nF, the rising and falling time of the 22KHz modulation wave is controlled to be about 8 mu s, and in order to meet the falling amplitude requirement of 700mV/8 mu s of modulation wave in an empty state, a pull-down current larger than 26mA is needed to be provided for the LNB end so as to quickly release the charge of the output capacitance. In the prior art, in order to realize the pull-down requirement, when 22KHz modulation is carried out, a direct current fixed load larger than 26mA is directly connected in parallel to an LNB output power supply end, and the slope of the falling edge of a modulated wave is ensured to reach the standard through continuous direct current. However, this approach generates a significant amount of power consumption, which significantly reduces the power conversion efficiency during LNB power modulation. Disclosure of Invention The embodiment of the application provides a pulse current generation circuit, a low-noise frequency demultiplier and a satellite receiver, which can solve the problem that the prior mode can generate a large amount of power consumption and greatly reduce the power conversion efficiency in the LNB power supply modulation process. In a first aspect, an embodiment of the present application provides a pulse current generating circuit, which is applied to a low noise frequency demultiplier, where the pulse current generating circuit includes a pulse generating module, a current generating module and a current mirror module, the current generating module is electrically connected with the pulse generating module and the current mirror module, respectively, and the current mirror module is electrically connected with an output end of an LDO in the low noise frequency demultiplier; The current generation module is used for receiving the square wave signal and outputting a first pulse voltage when the square wave signal falls, the current generation module is used for generating a first current according to the first pulse voltage, and the current mirror module is used for outputting a pulse current according to the first current, wherein the pulse current is a pull-down current connected to the output end of the LDO. In a possible implementation manner of the first aspect, the pulse generating module includes a pulse generator electrically connected to the current generating module for outputting the first pulse voltage at a falling edge of the square wave signal. In a possible implementation manner of the first aspect, the current generating module includes an operational amplifier unit and a resistor unit, and the operational amplifier unit is electrically connected with the pulse generating module, the resistor unit and the current mirror module respectively; the operational amplifier unit is used for obtaining an operational amplifier voltage according to the first pulse voltage, and the resistor unit is used for converting the operational amplifier voltage into the first current. In a possible implementation manner of the first aspect, the operational amplifier unit includes a first operational amplifier and a first transistor, a first input end of the first operational amplifier is electrically connected with the pulse generating module, a second input end of the first operational amplifier is electrically connected with a source electrode of the first transistor and the resistor unit, an output end of the