CN-122026827-A - Overcurrent protection circuit and radio frequency power amplifier

CN122026827ACN 122026827 ACN122026827 ACN 122026827ACN-122026827-A

Abstract

The application provides an overcurrent protection circuit and a radio frequency power amplifier, which relate to the technical field of semiconductors and comprise a bias current module, a current detection module and a current control module, wherein the bias current module is used for outputting bias current to the power amplifier, the current detection module is used for detecting target current in the bias current module and generating a detection signal, the target current is related to the bias current, and the current control module is configured to regulate the bias current under the condition that the detection signal indicates that the target current exceeds a preset current threshold value. According to the overcurrent protection circuit and the radio frequency power amplifier, the current detection function is removed from the main signal path with high power and high performance sensitivity, so that the problem of performance deterioration of the amplifier caused by series detection resistors in the related art is avoided, and the detection element is more flexible to realize and smaller in occupied area due to smaller detected current value, so that the performance of the amplifier is optimized and the chip is miniaturized.

Inventors

JIANG ZHONGDONG
GAO ANMING
ZHENG LEI
JIANG WEI

Assignees

浙江星曜半导体有限公司

Dates

Publication Date: 20260512
Application Date: 20251231

Claims (10)

1. An overcurrent protection circuit, comprising: the bias current module is used for outputting bias current to the power amplifier; The current detection module is connected with the bias current module and is used for detecting target current in the bias current module and generating a detection signal, wherein the target current is related to the bias current; And the current control module is connected with the current detection module and the bias current module and is configured to adjust the bias current under the condition that the detection signal indicates that the target current exceeds a preset current threshold value.
2. The overcurrent protection circuit of claim 1, wherein the current detection module comprises a detection resistor connected in series in a path of the target current in the bias current module; The detection signal is a voltage drop generated by the target current flowing through the detection resistor.
3. The overcurrent protection circuit of claim 2, wherein the bias current module comprises a control current output sub-module and a bias current output sub-module; the control current output submodule is connected with the bias current output submodule and is used for outputting control current and controlling the target current; The bias current output sub-module is used for outputting the bias current based on the target current.
4. The overcurrent protection circuit of claim 3, wherein the bias current output sub-module is a control transistor; The base electrode of the control triode is connected with the control current output submodule and is used for inputting control current; The collector electrode of the control triode is connected with the detection resistor in series and is used for inputting the target current; And the emitter of the control triode is connected with the power amplifier and is used for outputting the bias current.
5. The overcurrent protection circuit of claim 2, wherein the current control module comprises a voltage comparison sub-module and a current regulation sub-module; The voltage comparison sub-module is used for comparing the voltage drop generated by the detection resistor with the voltage drop corresponding to the preset current threshold value to determine a voltage comparison signal, and the voltage comparison signal is used for controlling the current regulation sub-module to shunt the control current; The current regulation submodule is connected with the bias current module and used for shunting the control current so as to regulate the bias current.
6. The overcurrent protection circuit of claim 5, wherein the voltage comparison sub-module comprises an amplifier and a comparator; The input end of the amplifier is respectively connected with two ends of the detection resistor and is used for inputting the voltage drop generated by the target current flowing through the detection resistor; The first input end of the comparator is connected with the output end of the amplifier, the second input end is used for inputting the voltage drop corresponding to the preset current threshold value, and the output end is used for outputting the voltage comparison signal.
7. The overcurrent protection circuit of claim 5, wherein the current regulation submodule is a shunt triode; the base electrode of the shunt triode is connected with the voltage comparison submodule and is used for inputting a voltage comparison signal; The collector electrode of the shunt triode is connected with the control current output submodule; and the emitter of the shunt triode is connected with the shunt resistor.
8. A radio frequency power amplifier comprising at least one overcurrent protection circuit as claimed in any one of claims 1 to 7.
9. The radio frequency power amplifier of claim 8, comprising two cascaded first and second power amplifiers; the first power amplifier and the second power amplifier are respectively and independently provided with the overcurrent protection circuit.
10. The radio frequency power amplifier of claim 8, comprising two cascaded first and second power amplifiers, wherein the over-current protection circuit comprises a first bias current module and a second bias current module; the first bias current module outputs bias current to the first power amplifier; the second bias current module outputs bias current to the second power amplifier; the current detection module of the overcurrent protection circuit is connected with the second bias current module; The current control module of the overcurrent protection circuit is connected with the first bias current module.

Description

Overcurrent protection circuit and radio frequency power amplifier Technical Field The present application relates to the field of semiconductor technologies, and in particular, to an overcurrent protection circuit and a radio frequency power amplifier. Background In order to improve the long-term reliability of the power amplifier in the radio frequency module, the power amplifier needs to be over-current protected. In the case of overcurrent protection in the related art, a sense resistor is typically connected in series to a main current path (e.g., a collector terminal) of a power amplifier. Since the main current is large, even a small sense resistor produces a significant voltage drop. This voltage drop can directly reduce the available voltage swing at the collector of the amplifier, thereby deteriorating the performance of the power amplifier. Disclosure of Invention The application provides an overcurrent protection circuit and a radio frequency power amplifier, which are used for solving the technical problem that the performance of the radio frequency power amplifier is not deteriorated when the overcurrent protection is carried out on the radio frequency power amplifier. The application provides an overcurrent protection circuit, comprising: the bias current module is connected with the power amplifier and is used for outputting bias current to the power amplifier; The current detection module is connected with the bias current module and is used for detecting target current in the bias current module and generating a detection signal, wherein the target current is related to the bias current; And the current control module is connected with the current detection module and the bias current module and is configured to adjust the bias current under the condition that the detection signal indicates that the target current exceeds a preset current threshold value. In some embodiments, the current detection module comprises a detection resistor connected in series in the path of the target current in the bias current module; The detection signal is a voltage drop generated by the target current flowing through the detection resistor. In some embodiments, the bias current module includes a control current output sub-module and a bias current output sub-module; the control current output submodule is connected with the bias current output submodule and is used for outputting control current and controlling the target current; The bias current output sub-module is used for outputting the bias current based on the target current. In some embodiments, the bias current output sub-module is a control transistor; The base electrode of the control triode is connected with the control current output submodule and is used for inputting control current; The collector electrode of the control triode is connected with the detection resistor in series and is used for inputting the target current; And the emitter of the control triode is connected with the power amplifier and is used for outputting the bias current. In some embodiments, the current control module includes a voltage comparison sub-module and a current regulation sub-module; The voltage comparison sub-module is used for comparing the voltage drop generated by the detection resistor with the voltage drop corresponding to the preset current threshold value to determine a voltage comparison signal, and the voltage comparison signal is used for controlling the current regulation sub-module to shunt the control current; The current regulation submodule is connected with the bias current module and used for shunting the control current so as to regulate the bias current. In some embodiments, the voltage comparison sub-module includes an amplifier and a comparator; The input end of the amplifier is respectively connected with two ends of the detection resistor and is used for inputting the voltage drop generated by the target current flowing through the detection resistor; The first input end of the comparator is connected with the output end of the amplifier, the second input end is used for inputting the voltage drop corresponding to the preset current threshold value, and the output end is used for outputting the voltage comparison signal. In some embodiments, the current regulation sub-module is a shunt triode; the base electrode of the shunt triode is connected with the voltage comparison submodule and is used for inputting a voltage comparison signal; The collector electrode of the shunt triode is connected with the control current output submodule; and the emitter of the shunt triode is connected with the shunt resistor. The application provides a radio frequency power amplifier, which comprises at least one overcurrent protection circuit. In some embodiments, two cascaded first and second power amplifiers are included; the first power amplifier and the second power amplifier are respectively and independently provided with the overcurrent protection