摘要:
A switched-capacitor circuit comprising a differential operational amplifier (206) and a feedback circuit (204A, 204B) is described. In some embodiments, the feedback circuit (204A, 204B) may be configured to provide a reference voltage (Vr1, Vr2) that is insensitive to temperature and/or process variations. In some embodiments, the feedback circuit may be configured to mitigate the time delay associated with one or more capacitors (Cs1, Cs2) of the switched-capacitor circuit. The switched-capacitor circuit may be controlled by a pair of control signals. During a first phase, one or more capacitors (Cs1, Cs2) may be charged, or discharged, through an input signal (Vi+, Vi-). During a second phase, the electric charge of the one or more capacitors (Cs1, Cs2) may be retained.
摘要:
In a wide-range low-noise amplifier: an input terminal is connected to a base terminal of a first transistor, one end of a first passive element, and one end of a third passive element; an emitter terminal of the first transistor is grounded; a collector terminal of the first transistor is connected an output terminal, a base terminal of the second transistor, one end of a capacitance element, and one end of a second passive element; the other end of the first passive element is connected to the other end of the capacitance element; an emitter terminal of the second transistor is connected to the other end of the third passive element; and a power terminal is connected to a collector terminal of the second transistor and the other end of the second passive element. The amplifier decides an impedance of the third passive element in accordance with an impedance of the first transistor whose emitter size has been decided so as to be appropriate for a desired saturation level of the amplifier, thereby adjusting the input impedance.
摘要:
A first circuit unit (22) of an audio amplifier includes a first emitter follower (Q1) connected to a pre stage input terminal (1), a second emitter follower (Q5) connected to a pre stage second input terminal (2), a main transistor (Q7) connected to an output path of the first emitter follower (Q1) and an output path of the second emitter follower (Q5), a first resistor (R14) and a second resistor (R16), which are series-connected between the output path of the first emitter follower (Q1) and a DC voltage source (E1), and a zener diode (D3) connected to a series-connection point between the first resistor (R14) and the second resistor (R16). A second circuit unit (24) has a complementary configuration to the first circuit unit (22). A collector path of each first and second emitter followers is connected to the series-connection point in the other circuit unit.
摘要:
A device includes a main low noise amplifier, LNA, stage (410) configured to amplify a single-ended communication signal (RFin), an auxiliary LNA stage (420) coupled to the main LNA stage (410), the auxiliary LNA stage (420) configured to cancel non-linear second order products generated by the main LNA stage (410), and a load circuit (430) configured to receive an output of the main LNA stage (410) and an output of the auxiliary LNA stage (420), the load circuit (430) configured to convert the single-ended communication signal (RFin) to a differential signal.
摘要:
Described herein is an apparatus and system of a low-impedance reference voltage generator. The apparatus comprises: a voltage-control loop including a first transistor to provide an output voltage; and a current-control loop to sense current through the first transistor, relative to a reference current. The node having the output voltage is a low-impedance node.
摘要:
A low noise amplifying (LNA) circuit comprising an amplifying section (11, 12) and a feedback means (14) arranged for providing input matching from the output to the input. The LNA circuit further comprises at least one frequency band determining inductor (15) having a predetermined resonance frequency for influencing at least one frequency band in which the amplifying section operates. The at least one inductor is directly connected to the output of the circuit and the feedback means (14) provides a feedback connection for the section (s) to the input. In this way, the at least one frequency band in which the amplifying section operates is substantially completely determined by the at least one frequency band determining inductor (15).
摘要:
A low noise amplifying circuit (LNA) operating in at least one frequency band is presented. The low noise amplifying circuit comprises a cascode amplifier (11,12), at least one inductor (15,16) and a source follower (14) connected between the output (Out) and the input (In) of the LNA. The source follower, which may comprise a resistor connected between the source terminal of the source follower and the input terminal, provides input matching. The at least one inductor (15,16) is connected to the drain terminal of the cascode transistor (12). The value of this inductor is selected to resonate with the total load capacitance at the desired operating frequency.
摘要:
Described herein is an apparatus and system of a low-impedance reference voltage generator. The apparatus comprises: a voltage-control loop including a first transistor to provide an output voltage; and a current-control loop to sense current through the first transistor, relative to a reference current. The node having the output voltage is a low-impedance node.