Power amplifier systems with control interface and bias circuit
One aspect of this disclosure is a power amplifier system that includes a control interface, a power amplifier, a passive component, and a bias circuit. The power amplifier and the passive component can be on a first die. The bias circuit can be on a second die. The control interface can operate as a serial interface or as a general purpose input/output interface. The power amplifier can be controllable based at least partly on an output signal from the control interface. The bias circuit can generate a bias signal based at least partly on an indication of the electrical property of the passive component. Other embodiments of the system are provided along with related methods and components thereof.
1. A power amplifier system comprising:
a control interface configured to receive an input signal, operate as a serial interface in response to the input signal having a first value, operate as a general purpose input/output interface in response to the input signal having a second value, and provide an output signal;
a power amplifier configured to amplify a radio frequency signal, the power amplifier controllable based at least partly on the output signal;
a passive component having an electrical property that depends on a condition of a die that includes the passive component and the power amplifier; and
a bias circuit included on a different die than the power amplifier, the bias circuit configured to generate a bias signal based at least partly on an indication of the electrical property of the passive component.
2. The power amplifier system of claim 1 wherein the control interface is configured to set a mode of the power amplifier.
3. The power amplifier system of claim 1 wherein the passive component includes a resistor and the electrical property is a resistance.
4. The power amplifier system of claim 1 wherein the power amplifier includes a heterojunction bipolar transistor, and the passive component includes a semiconductor resistor having a resistive layer formed of a material that is substantially the same as a material of a layer of the heterojunction bipolar transistor.
5. The power amplifier system of claim 4 wherein an emitter of the heterojunction bipolar transistor includes the layer.
6. The power amplifier system of claim 4 wherein a base of the heterojunction bipolar transistor includes the layer.
7. The power amplifier system of claim 1 wherein the condition of the die is temperature of the die.
8. The power amplifier system of claim 1 wherein the condition of the die is a process variation associated with the die.
9. The power amplifier system of claim 1 wherein the condition of the die is a beta parameter associated with the die.
10. The power amplifier system of claim 1 wherein the input signal is a voltage input/output signal.
11. The power amplifier system of claim 10 wherein the control interface is configured to receive the voltage input/output signal at a single voltage input/output pin.
12. The power amplifier system of claim 1 wherein the control interface includes a tri-state buffer operable in a first state for reading data from the serial interface and operable in a second state for writing data to the serial interface.
13. The power amplifier system of claim 1 wherein the control interface includes a combinational logic block and a level shifter, the combinational logic block is configured to provide a signal to the level shifter, and the level shifter is configured to provide the output signal.
14. A power amplifier system comprising:
a digital control interface configured to receive a voltage input/output signal at a voltage/input output pin, operate as a serial interface in response to the voltage input/output signal having a first logic value, operate as a general purpose input/output interface in response to the voltage input/output signal having a second logic value, and provide an output signal;
a power amplifier that is controllable based at least partly on the output signal;
a resistor having a resistance that depends on a condition of a die that includes the resistor and the power amplifier; and
a bias circuit included on a different die than the power amplifier, the bias circuit configured to generate a bias signal based at least partly on an indication of the resistance of the resistor.
15. The power amplifier system of claim 14 wherein the power amplifier includes a heterojunction bipolar transistor, and the resistor includes a resistive layer formed of a material that is substantially the same as a material of a layer of the heterojunction bipolar transistor.
16. The power amplifier system of claim 14 wherein the digital control interface includes a combinational logic block and a level shifter, the combinational logic block is configured to provide a signal to the level shifter, and the level shifter is configured to provide the output signal.
17. A power amplifier system comprising:
a power amplifier configured to amplify a radio frequency signal;
a control interface including a serial interface and a general purpose input/output interface, the control interface configured to set a mode of the power amplifier;
a passive component having an electrical property that depends on a condition of a die that includes the passive component and the power amplifier; and
a bias circuit included on a different die than the power amplifier, the bias circuit configured to generate a bias signal based at least partly on an indication of the electrical property of the passive component.
18. The power amplifier system of claim 17 wherein the passive component is a semiconductor resistor.
19. The power amplifier system of claim 17 wherein the control interface is configured to receive a voltage input/output signal and activate the general purpose input/output interface based on a signal level of the voltage input/output signal.
20. The power amplifier system of claim 18 wherein the power amplifier includes a heterojunction bipolar transistor, and the semiconductor resistor has a resistive layer formed of a material that is substantially the same as a material of a layer of the heterojunction bipolar transistor.