Certain aspects of the present disclosure generally relate to a low voltage, accurate current mirror, which may be used for distributed sensing of a remote current in an integrated circuit (IC). One example current mirror typically includes a first pair of transistors, a second pair of transistors in cascode with the first pair of transistors, a switching network coupled to the second pair of transistors, and a third pair of transistors coupled to the switching network. An input node between the first and second pairs of transistors may be configured to receive an input current for the current mirror, and an output node at the first pair of transistors may be configured to sink an output current for the current mirror, proportional to the input current. This current mirror architecture offers a hybrid low-voltage/high-voltage solution, tolerates low input voltages, provides high output impedance, and offers low area and power consumption.

Certain aspects of the present disclosure generally relate to a low voltage, accurate current mirror, which may be used for distributed sensing of a remote current in an integrated circuit (IC). One example current mirror typically includes a first pair of transistors, a second pair of transistors in cascode with the first pair of transistors, a switching network coupled to the second pair of transistors, and a third pair of transistors coupled to the switching network. An input node between the first and second pairs of transistors may be configured to receive an input current for the current mirror, and an output node at the first pair of transistors may be configured to sink an output current for the current mirror, proportional to the input current. This current mirror architecture offers a hybrid low-voltage/high-voltage solution, tolerates low input voltages, provides high output impedance, and offers low area and power consumption.

One aspect of this disclosure is a power amplifier module that includes a power amplifier configured to amplify a radio frequency (RF) signal and an RF transmission line electrically coupled to an output of the power amplifier. The power amplifier includes a heterojunction bipolar transistor and a p-type field effect transistor, in which a semiconductor portion of the p-type field effect transistor corresponds to a channel includes the same type of semiconductor material as a collector layer of the heterojunction bipolar transistor. The RF transmission line includes a nickel layer with a thickness that is less than 0.5 um, a conductive layer under the nickel layer, a palladium layer over the nickel layer, and a gold layer over the palladium layer. Other embodiments of the module are provided along with related methods and components thereof.

A constant voltage circuit stabilizes a voltage V that occurs at a capacitor connection terminal. An internal circuit operates based on the voltage that occurs at the capacitor connection terminal. A first voltage dividing circuit generates a first voltage, which is obtained by dividing the power supply voltage that occurs at the power supply terminal, at the capacitor connection terminal. A charging transistor is arranged with one end coupled to the capacitor connection terminal. A second voltage dividing circuit generates a second voltage obtained by dividing the power supply voltage at a control terminal of the charging transistor. A clamp circuit clamps the voltage that occurs at the capacitor connection terminal and the voltage at the control terminal of the charging transistor so as to prevent them from exceeding a limit voltage.

A power amplifier module includes a power amplifier including a GaAs bipolar transistor having a collector, a base abutting the collector, and an emitter, the collector having a doping concentration of at least about 310.sup.16 cm.sup.3 at a junction with the base, the collector also having at least a first grading in which doping concentration increases away from the base; and an RF transmission line driven by the power amplifier, the RF transmission line including a conductive layer and finish plating on the conductive layer, the finish plating including a gold layer, a palladium layer proximate the gold layer, and a diffusion barrier layer proximate the palladium layer, the diffusion barrier layer including nickel and having a thickness that is less than about the skin depth of nickel at 0.9 GHZ. Other embodiments of the module are provided along with related methods and components thereof.

One aspect of this disclosure is a power amplifier module that includes a power amplifier configured to provide a radio frequency signal at an output, an output matching network coupled to the output of the power amplifier and configured to provide impedance matching at a fundamental frequency of the radio frequency signal, and a harmonic termination circuit coupled to the output of the power amplifier. The power amplifier is included on a power amplifier die. The output matching network can include a first circuit element electrically connected to an output of the power amplifier by way of a pad on a top surface of a conductive trace, in which the top surface has an unplated portion between the pad the power amplifier die. The harmonic termination circuit can include a second circuit element. The first and second circuit elements can have separate electrical connections to the power amplifier die. Other embodiments of the module are provided along with related methods and components thereof.

An apparatuses and methods for buffering a voltage from a circuit without current drive ability are described. An example apparatus includes a voltage buffer that includes two identical stages. The first stage is configured to receive an input voltage and produce an intermediate voltage as an output. The second stage is configured to receive the intermediate voltage and provide an output voltage that is equal to the input voltage. The voltage buffer may be coupled to a current source. The second stage of the voltage buffer may have current drive ability.

An apparatuses and methods for buffering a voltage from a circuit without current drive ability are described. An example apparatus includes a voltage buffer that includes two identical stages. The first stage is configured to receive an input voltage and produce an intermediate voltage as an output. The second stage is configured to receive the intermediate voltage and provide an output voltage that is equal to the input voltage. The voltage buffer may be coupled to a current source. The second stage of the voltage buffer may have current drive ability.

An apparatuses and methods for buffering a voltage from a circuit without current drive ability are described. An example apparatus includes a voltage buffer that includes two identical stages. The first stage is configured to receive an input voltage and produce an intermediate voltage as an output. The second stage is configured to receive the intermediate voltage and provide an output voltage that is equal to the input voltage. The voltage buffer may be coupled to a current source. The second stage of the voltage buffer may have current drive ability.

An apparatuses and methods for buffering a voltage from a circuit without current drive ability are described. An example apparatus includes a voltage buffer that includes two identical stages. The first stage is configured to receive an input voltage and produce an intermediate voltage as an output. The second stage is configured to receive the intermediate voltage and provide an output voltage that is equal to the input voltage. The voltage buffer may be coupled to a current source. The second stage of the voltage buffer may have current drive ability.