6 results about "Transconductance" patented technology

A transconductance amplifier mirror circuit is connected to an electrode for sensing the capacitance of the electrode with reference to ground, or the capacitance between the electrode and another electrode. A voltage level change is produced on the electrode connected to the transconductance amplifier mirror circuit to cause the transconductance amplifier mirror circuit to supply charges to or drain charges from a charge calculation circuit. The charge amount variation is converted to a signal for calculating the sensed capacitance.

A temperature sensing circuit using CMOS switch-capacitor includes a PNP BJT, a hysteresis comparator, a transconductance amplifier, two current sources, two capacitors, and six switches. A voltage complementary to the absolute temperature (CTAT) is generated according to the PNP BJT, and a voltage proportional to the absolute temperature (PTAT) is generated according to two capacitors and the transconductance amplifier. When the voltage proportional to absolute temperature is greater than the voltage complementary to absolute temperature as the temperature rising, the hysteresis comparator outputs a high level signal.

The invention relates to a high-gain low-noise frequency mixer which comprises a switch level module and an active load module. The common-mode voltage output end of the switch level module is connected with a common-mode feedback module which is used for stabilizing the common-mode voltage, the output end of the common-mode feedback module is connected with the active load module, the output end of the active load module is connected with the switch level module and a dual-capacitor cross coupled transconductance module, the switch level module is also connected with a tail current source module, and the switch level module uses an active Gilbert double-balance structure. According to the technical scheme, the equivalent transconductance value is effectively improved by using a gate drive and substrate drive dual-capacitor cross coupling manner on the basis of a traditional folded structure transconductance; and on the premise that the power consumption is not increase, the noise coefficient of the frequency mixer is reduced, and the gain of the frequency mixer is improved. Use of the active load module improves the conversion gain of the frequency mixer, and the common-mode feedback module is used to stabilize the common-mode voltage of the output point and improve the linearity of the frequency mixer.

The invention discloses an amplifier circuit which comprises an input transconductance circuit, an output circuit and a distortion offset feedback loop, wherein the distortion offset feedback loop comprises a third triode, a fourth triode, a fifth triode, a sixth triode, a first resistor and a second resistor, wherein a base electrode of the third triode is connected with that of the fourth triode; an emitting electrode of the third triode is connected with that of the fourth triode; the emitting electrode of the fourth electrode is connected with a bias voltage; a base electrode of the second triode is respectively connected with a collecting electrode of the second triode and a base electrode of the third triode; a base electrode of the fifth triode is connected with that of the six triode; the collecting electrode of the fifth triode is respectively connected with a base plate of the fifth triode and a collecting electrode of the fourth triode; an emitting electrode of the fifth triode is grounded by virtue of the first resistor; a collecting electrode of the six triode is connected to the emitting electrode of the second triode; an emitting electrode of the sixth triode is grounded by virtue of the second resistor. According to the amplifier circuit, a distortion offset technology is adopted, so that the OIP3 output performance is improved.

The invention discloses a voltage and current control circuit and an integrated chip. The voltage and current control circuit comprises a first output end, a second output end, a current loop and a voltage loop. The current loop comprises a current sampling unit, a first error amplification unit and a first transconductance unit. The voltage loop comprises a voltage dividing unit, a second error amplification unit and a second transconductance unit. The current sampling unit is used for obtaining first current. The first error amplification unit is used for outputting a first voltage according to the difference between the first current and the reference current. The first transconductance unit is used for outputting a second current according to the first voltage. The voltage dividing unit is used for outputting a second voltage and outputting a third voltage according to the second current. The second error amplification unit is used for outputting a fourth voltage and a fifth voltage. And the second transconductance unit is used for outputting a third current according to the fourth voltage and outputting a fourth current according to the fifth voltage. In this way, pins connected with an external circuit can be reduced, and the cost is low.