Patent classifications
H03F2200/447
Transmission circuit and operation method having output power compensation mechanism
The present invention discloses a transmission circuit having output power compensation mechanism. A base-band circuit receives and processes a digital input signal to perform conversion and amplification according to at least one gain parameter to generate an analog output signal. A frequency up-converting circuit performs frequency up-conversion on the analog output signal to generate an RF signal. A RF amplification circuit amplifies the RF signal to generate an output RF signal to an antenna. A temperature monitoring circuit monitors temperature of the RF amplification circuit to generate an instant temperature value thereof. A calibration circuit increases at least a part of the gain parameter when the instant temperature value makes a power of the RF amplification circuit decrease and decreases at least a part of the gain parameter when the instant temperature value makes the power increase.
OFFSET CORRECTION CIRCUIT
A first correction voltage generation circuit provides a first positive or negative correction voltage for correcting an input voltage. A second correction voltage generation circuit provides a second correction voltage identical in polarity to the first correction voltage in accordance with the first correction voltage. The second correction voltage is generated to have a temperature coefficient reverse in polarity to a temperature coefficient of the first correction voltage.
METHODS AND APPARATUS TO IMPROVE PERFORMANCE OF AMPLIFIERS
An example apparatus includes: An amplifier comprising folded cascode circuitry having an input and an output, an input pair coupled to the input, clamp circuitry including: a first transistor having a first drain, a first source, and a first gate, the first source coupled to the output, a second transistor having a second drain, a second source, and a second gate, the second drain coupled to the first drain and the second gate coupled to the first drain and second drain, a third transistor having a third drain, a third source, and a third gate, the third source coupled to the output, and a fourth transistor having a fourth drain, a fourth source, and a fourth gate, the fourth drain coupled to the third drain and the fourth gate coupled to the third drain and the fourth drain.
Amplification interface, and corresponding measurement system and method for operating an amplification interface
An electronic amplification-interface circuit includes a differential-current reading circuit having a first input terminal and a second input terminal. The differential-current reading circuit includes a continuous-time sigma-delta conversion circuit formed by an integrator-and-adder module generating an output signal that is coupled to an input of a multilevel-quantizer circuit configured to output a multilevel quantized signal. The integrator-and-adder module includes a differential current-integrator circuit configured to output a voltage proportional to an integral of a difference between currents received at the first and second input terminals. A digital-to-analog converter, driven by a respective reference current, receives and converts the multilevel quantized signal into a differential analog feedback signal. The integrator-and-adder module adds the differential analog feedback signal to the differential signal formed at the first and second input terminals.
OVER TEMPERATURE PROTECTION OF LDO CONTROLLING THE RF POWER AMPLIFIER COLLECTOR VOLTAGE
A power control circuit coupled to a power amplifier, said power control circuit comprising: a first circuit including a power supply and a first transistor to provide a first current to the power amplifier through the first transistor; a second circuit to provide a second current to the power amplifier, the power dissipation of the first current being dependent on the second current of the power amplifier; a protective circuit coupled to the second circuit, the protective circuit configured to pull down a voltage of the second circuit when the temperature of the power control circuit exceeds a threshold temperature, such that the second current provided to the power amplifier by the second circuit is reduced and the power dissipation in the first transistor of the first circuit is reduced with increasing temperature.
Semiconductor integrated circuit
A semiconductor integrated circuit is capable of electrically connecting to a capacitance variable capacitor whose electrostatic capacitance changes corresponding to an environmental change between a first and a second capacitances and determines whether the electrostatic capacitance of the capacitance variable capacitor has changed to exceed a reference capacitance value. The semiconductor integrated circuit includes a reference capacitor having a fixed electrostatic capacitance between the first capacitance and the second capacitance as the reference capacitance value; and an amplifier circuit, charging the capacitance variable capacitor via a first node and charging the reference capacitor via a second node corresponding to a clock signal, amplifying a potential difference between a potential of the first node and a potential of the second node, and outputting a binary determination signal indicating whether the electrostatic capacitance of the capacitance variable capacitor has changed to exceed the reference capacitance value based on the amplified potential difference.
A CIRCUIT ASSEMBLY FOR GENERATING A CONSTANT CURRENT
A circuit assembly for generating a constant current, the circuit comprising: a resistor pair including a first resistor and a second resistor, the first resistor having a positive temperature coefficient and the second resistor having a negative temperature coefficient, the first and second resistors being configured such that the variability of resistance over temperature of the first resistor and the variability of resistance over temperature of the second resistor cancel to produce a zero temperature coefficient for the resistor pair; and a voltage input connected to the resistor pair and configured to receive an input voltage, the voltage input and the resistor pair configured to generate a current with a zero temperature coefficient.
Power amplifier capable of maintaining constant gain regardless of temperature variations
A power amplifier includes a transistor, a temperature sensor and a filter. The transistor is used to receive a bias signal and amplify a radio frequency (RF) signal. The temperature sensor is arranged in proximity to the transistor, and is used to detect a temperature of the transistor to provide a voltage signal at a control node accordingly. The filter is coupled to the temperature sensor and is used to filter the voltage signal to generate a filtered voltage. The bias signal is adjusted according to the filtered voltage.
REFERENCE GENERATION CIRCUIT FOR MAINTAINING TEMPERATURE-TRACKED LINEARITY IN AMPLIFIER WITH ADJUSTABLE HIGH-FREQUENCY GAIN
Equalizing an input signal according to a receiver equalizer peaking circuit having a capacitor FET (CFET) providing a capacitive value and a resistor FET (RFET) providing a resistive value, generating a capacitor control voltage at a gate of the CFET using a capacitor controller DAC based on a first reference voltage, and a RFET control voltage at a gate of the RFET using a resistor controller DAC based on a second reference voltage, generating the first reference voltage using a replica input FET, the first reference voltage varying according to a threshold voltage (Vt) of an input FET, providing the first reference voltage to the capacitor controller DAC, generating the second reference voltage using a replica RFET, the second reference voltage varying with respect to the first reference voltage and a Vt of the replica of the RFET, and providing the second reference voltage to the resistor controller DAC.
Temperature detector
A temperature detector is used to detect a temperature of a circuit under test, and includes a temperature coefficient component, a multiplier, an impedance component and a node. The temperature coefficient component is arranged in proximity to the circuit under test. A control terminal of the multiplier is coupled to a second terminal of the temperature coefficient component. The impedance component is coupled between the second terminal of the temperature coefficient component and the control terminal of the multiplier, or between a second terminal of the multiplier and a third voltage terminal. The node is formed between the second terminal of the temperature coefficient component and the control terminal of the multiplier. A voltage at the node and an amplified detection current flowing to a first terminal of the multiplier are positively correlated to the temperature of the circuit under test.