Voltage-to-current architecture and error correction schemes

Patent metadata

Field	Value
Publication number	US-2023137935-A1
Application number	US-202218146832-A
Country	US
Kind code	A1
Filing date	Dec 27, 2022
Priority date	Jan 24, 2020
Publication date	May 4, 2023
Grant date	—

Abstract

Certain aspects of the present disclosure are generally directed to circuitry and techniques for voltage-to-current conversion. For example, certain aspects provide a circuit for signal amplification including a first amplifier; a first transistor, a gate of the first transistor being coupled to an output of the first amplifier and a drain of the first transistor being coupled to an output node of circuit; a first resistive element coupled between a first input node of the circuit and an input of the first amplifier; a second amplifier; a second transistor, a gate of the second transistor being coupled to an output of the second amplifier and a drain of the second transistor being coupled to the output node of circuit; and a second resistive element coupled between a second input node of the circuit and an input of the second amplifier.

First claim

What is claimed is:

1 . An audio system with an H-bridge amplifier for driving a speaker, the audio system comprising:
a first path coupled between a first voltage rail and an audio output for coupling to the speaker, the first path including a first switch and a first sense element; a second path coupled between the audio output for coupling to the speaker and a second voltage rail, the second path including a second switch and a second sense element; a voltage-to-current circuit coupling the first and second sense elements; and one or more configurable circuit elements coupled to one or more output nodes of the voltage-to-current circuit.

2 . The audio system of claim 1 , wherein the one or more configurable circuit elements comprise one or more capacitive elements.

3 . The audio system of claim 2 , further comprising a plurality of switches coupled to the capacitive elements, wherein each of the switches is configured to selectively couple one of the capacitive elements to a third voltage rail or a fourth voltage rail.

4 . The audio system of claim 3 , wherein the third voltage rail is configured to have a voltage that is a fraction of a voltage of the first voltage rail and wherein the fourth voltage rail is a reference potential node for the audio system.

5 . The audio system of claim 2 , wherein at least one of the capacitive elements is coupled to a third voltage rail and wherein at least another one of the capacitive elements is coupled to a fourth voltage rail configured to have a different voltage than the third voltage rail.

6 . The audio system of claim 2 , wherein the one or more capacitive elements are configured to reduce second harmonic distortion in one or more signals at the output nodes of the voltage-to-current circuit.

7 . The audio system of claim 2 , wherein at least one of the capacitive elements is a variable capacitive element.

8 . The audio system of claim 1 , wherein the audio system is configured to sense a temperature of a coil of the speaker and avoid coil burnout.

9 . The audio system of claim 8 , wherein the first and second sense elements are configured to sense a drive current for the speaker and wherein the temperature of the coil of the speaker is based on the sensed drive current for the speaker.

10 . The audio system of claim 1 , wherein the audio system is configured to protect the speaker by adjusting a gain of the H-bridge amplifier based on one or more signals at the one or more output nodes of the voltage-to-current circuit.

11 . The audio system of claim 1 , further comprising a summing amplifier having one or more inputs coupled to the one or more configurable circuit elements and to the one or more output nodes of the voltage-to-current circuit.

12 . The audio system of claim 1 , wherein the audio system is configured to determine a resonant frequency of a coil of the speaker and control an excursion of the speaker to avoid damage to a membrane of the speaker.

13 . The audio system of claim 12 , wherein the audio system is configured to measure an impedance to determine the resonant frequency of the coil of the speaker.

14 . The audio system of claim 1 , wherein each output node is coupled to both the first path and the second path.

15 . The audio system of claim 14 , wherein:
the one or more output nodes comprise a first output node and a second output node; the first output node is coupled to a first set of the one or more configurable circuit elements; and the second output node is coupled to a second set of the one or more configurable circuit elements, different from the first set.

16 . The audio system of claim 1 , wherein the first and second sense elements comprise resistive elements.

17 . The audio system of claim 1 , wherein the second voltage rail is a reference potential node for the audio system.

18 . The audio system of claim 1 , wherein the voltage-to-current circuit comprises at least one resistor calibration network.

19 . The audio system of claim 18 , wherein the voltage-to-current circuit further comprises a first sense path coupled to the first path and a second sense path coupled to the second path and wherein the at least one resistor calibration network is configured to adjust for a resistance mismatch between the first sense path and the second sense path.

20 . The audio system of claim 18 , wherein the at least one resistor calibration network comprises a plurality of resistive elements and a plurality of switches configured to selectively adjust an effective resistance of the resistor calibration network.

21 . The audio system of claim 1 , wherein the voltage-to-current circuit comprises a first sense path coupled to the first path, a second sense path coupled to the second path, and one or more resistive elements to adjust for a resistance mismatch between the first and second sense paths in the voltage-to-current circuit.

22 . The audio system of claim 1 , wherein the one or more configurable circuit elements are configured to inject one or more currents into the one or more output nodes of the voltage-to-current circuit.

23 . The audio system of claim 1 , wherein the one or more configurable circuit elements are configured to adjust an effective capacitance of the one or more output nodes of the voltage-to-current circuit.

Assignees

• Qualcomm Inc

Inventors

• Sivakumar Ramkumar
• Lu Jingxue
• Galal Sherif
• Zhang Xinwang
• YADAV Kshitij

Classifications

• H04R3/007 Primary

  Protection circuits for transducers · CPC title

• H03F1/0227

  using supply converters · CPC title

• H03F2200/462

  the current being sensed · CPC title

• H03F2200/481

  A resistor being used as sensor · CPC title

• H03F3/45475

  using IC blocks as the active amplifying circuit · CPC title