Aspects of this disclosure relate to an amplification circuit that includes a stacked amplifier and a bias circuit. The stacked amplifier includes at least a first transistor and a second transistor in series with each other. The stacked amplifier is operable in at least a first mode and a second mode. The bias circuit is configured to bias the second transistor to a linear region of operation in the first mode and to bias the second transistor as a switch in the second mode. In certain embodiments, the amplification circuit can be a power amplifier stage configured to receive a supply voltage that has a different voltage level in the first mode than in the second mode.

Aspects of this disclosure relate to an amplification circuit that includes a stacked amplifier and a bias circuit. The stacked amplifier includes at least a first transistor and a second transistor in series with each other. The stacked amplifier is operable in at least a first mode and a second mode. The bias circuit is configured to bias the second transistor to a linear region of operation in the first mode and to bias the second transistor as a switch in the second mode. In certain embodiments, the amplification circuit can be a power amplifier stage configured to receive a supply voltage that has a different voltage level in the first mode than in the second mode.

A multi-bandwidth envelope tracking (ET) integrated circuit (IC) (ETIC) and related apparatus are provided. In a non-limiting example, the multi-bandwidth ETIC is coupled to an amplifier circuit(s) configured to amplify a radio frequency (RF) signal corresponding to a wide range of modulation bandwidth (e.g., from less than 90 KHz to over 40 MHz). In this regard, the multi-bandwidth ETIC is configured to generate different ET voltages based on the modulation bandwidth of the RF signal. By generating the ET voltages based on the modulation bandwidth of the RF signal, it may be possible to optimize operating efficiency of the amplifier circuit(s). As a result, it may be possible to improve power consumption and reduce heat dissipation in an apparatus employing the multi-bandwidth ETIC, thus making it possible to provide the multi-bandwidth ETIC in a wearable device.

A multi-bandwidth envelope tracking (ET) integrated circuit (IC) (ETIC) and related apparatus are provided. In a non-limiting example, the multi-bandwidth ETIC is coupled to an amplifier circuit(s) configured to amplify a radio frequency (RF) signal corresponding to a wide range of modulation bandwidth (e.g., from less than 90 KHz to over 40 MHz). In this regard, the multi-bandwidth ETIC is configured to generate different ET voltages based on the modulation bandwidth of the RF signal. By generating the ET voltages based on the modulation bandwidth of the RF signal, it may be possible to optimize operating efficiency of the amplifier circuit(s). As a result, it may be possible to improve power consumption and reduce heat dissipation in an apparatus employing the multi-bandwidth ETIC, thus making it possible to provide the multi-bandwidth ETIC in a wearable device.

A multi-bandwidth envelope tracking (ET) integrated circuit (IC) (ETIC) is provided. The multi-bandwidth ETIC may be coupled to an amplifier circuit(s) for amplifying a radio frequency (RF) signal modulated in a wide range of modulation bandwidth. In examples discussed herein, the multi-bandwidth ETIC includes an ET voltage circuit configured to generate a modulated voltage based on a supply voltage. The supply voltage may be dynamically adjusted to cause the modulated voltage to transition quickly from one voltage level to another voltage level, particularly when the RF signal is modulated in a higher modulation bandwidth, without compromising efficiency of the ET voltage circuit. As such, the multi-bandwidth ETIC may generate different modulated voltages based on the modulation bandwidth of the RF signal, thus making it possible to employ the multi-bandwidth ETIC in a wide range of wireless communication devices, such as a fifth-generation (5G) wireless communication device.

A multi-bandwidth envelope tracking (ET) integrated circuit (IC) (ETIC) is provided. The multi-bandwidth ETIC may be coupled to an amplifier circuit(s) for amplifying a radio frequency (RF) signal modulated in a wide range of modulation bandwidth. In examples discussed herein, the multi-bandwidth ETIC includes an ET voltage circuit configured to generate a modulated voltage based on a supply voltage. The supply voltage may be dynamically adjusted to cause the modulated voltage to transition quickly from one voltage level to another voltage level, particularly when the RF signal is modulated in a higher modulation bandwidth, without compromising efficiency of the ET voltage circuit. As such, the multi-bandwidth ETIC may generate different modulated voltages based on the modulation bandwidth of the RF signal, thus making it possible to employ the multi-bandwidth ETIC in a wide range of wireless communication devices, such as a fifth-generation (5G) wireless communication device.

An amplifier circuit including a semiconductor element is formed on a substrate. A protection circuit is formed including a plurality of protection diodes that are formed on the substrate and that are connected in series with each other, the protection circuit being connected to an output terminal of the amplifier circuit. A pad conductive layer is formed that at least partially includes a pad for connecting to a circuit outside the substrate. An insulating protective film covers the pad conductive layer. The insulating protective film includes an opening that exposes a partial area of a surface of the pad conductive layer, and that covers another area. A first bump is formed on the pad conductive layer on a bottom surface of the opening, and a second bump at least partially overlaps the protection circuit in plan view and is connected to a ground (GND) potential connected to the amplifier circuit.

An amplifier circuit including a semiconductor element is formed on a substrate. A protection circuit is formed including a plurality of protection diodes that are formed on the substrate and that are connected in series with each other, the protection circuit being connected to an output terminal of the amplifier circuit. A pad conductive layer is formed that at least partially includes a pad for connecting to a circuit outside the substrate. An insulating protective film covers the pad conductive layer. The insulating protective film includes an opening that exposes a partial area of a surface of the pad conductive layer, and that covers another area. A first bump is formed on the pad conductive layer on a bottom surface of the opening, and a second bump at least partially overlaps the protection circuit in plan view and is connected to a ground (GND) potential connected to the amplifier circuit.

Envelope tracking can be employed to reduce power consumption of a power amplifier, but envelope tracking can introduce nonlinearities to a power amplifier. These nonlinearities can manifest themselves as noise at the output of the power amplifier. Embodiments described herein provide techniques for characterizing a parameter indicative of power amplifier noise when envelope tracking is employed. Measurement of this parameter can permit power amplifier designers to decide whether to forgo envelope tracking if a power amplifier is too susceptible to such noise, redesign the power amplifier to improve compatibility with envelope tracking, or to employ distortion compensation circuitry to reduce the noise output by the power amplifier. Counterintuitively, this distortion compensation circuitry may involve increasing the power, such as the envelope tracking power supply. However, increasing the power may be a desirable trade-off for increased linearity.

Envelope tracking can be employed to reduce power consumption of a power amplifier, but envelope tracking can introduce nonlinearities to a power amplifier. These nonlinearities can manifest themselves as noise at the output of the power amplifier. Embodiments described herein provide techniques for characterizing a parameter indicative of power amplifier noise when envelope tracking is employed. Measurement of this parameter can permit power amplifier designers to decide whether to forgo envelope tracking if a power amplifier is too susceptible to such noise, redesign the power amplifier to improve compatibility with envelope tracking, or to employ distortion compensation circuitry to reduce the noise output by the power amplifier. Counterintuitively, this distortion compensation circuitry may involve increasing the power, such as the envelope tracking power supply. However, increasing the power may be a desirable trade-off for increased linearity.