Driver circuitry

Patent metadata

Field	Value
Publication number	US-11658673-B2
Application number	US-202117380176-A
Country	US
Kind code	B2
Filing date	Jul 20, 2021
Priority date	Jul 31, 2020
Publication date	May 23, 2023
Grant date	May 23, 2023

Abstract

The present disclosure relates to circuitry comprising: digital circuitry configured to generate a digital output signal; and monitoring circuitry configured to monitor a supply voltage to the digital circuitry and to output a control signal for controlling operation of the digital circuitry, wherein the control signal is based on the supply voltage.

First claim

The invention claimed is:

1. Circuitry comprising:
digital circuitry configured to generate a digital output signal; and
monitoring circuitry configured to monitor a supply voltage to the digital circuitry and to output a control signal for controlling operation of the digital circuitry, wherein the control signal is based on the supply voltage;
wherein the monitoring circuitry is configured to receive an input signal for the digital circuitry and to output a modified input signal to the digital circuitry as the control signal, and wherein the digital circuitry is configured to generate the digital output signal based on the modified input signal.

2. Circuitry according to claim 1 , wherein the digital circuitry is operative to control a parameter of a digital output signal based on the control signal.

3. Circuitry according to claim 2 , wherein the digital circuitry is operative to control a pulse width of a pulse of the digital output signal based on the control signal to maintain a given average voltage per period of the digital output signal to compensate, at least partially, for a change in a magnitude of the supply voltage.

4. Circuitry according to claim 1 , wherein the monitoring circuitry comprises:
waveform generator circuitry configured to generate a voltage having an amplitude that changes over time based on a magnitude of the supply voltage;
comparator circuitry configured to compare the voltage to a reference voltage and to output a comparison signal when the voltage reaches the reference voltage; and
logic circuitry configured to receive the input signal and the comparison signal and to generate the modified input signal for the digital circuitry based on the input signal and the comparison signal.

5. Circuitry according to claim 1 , wherein the monitoring circuitry comprises:
analogue-to-digital converter (ADC) circuitry configured to generate a digital output signal based on the supply voltage;
timer circuitry configured to:
receive the input signal and the digital output signal;
commence timing a time period on detection of a feature of the input signal, wherein a duration of the time period is based on the digital output signal; and
output a timer output signal at the end of the time period; and

logic circuitry configured to receive the input signal and the timer output signal and to generate a modified input signal for the digital circuitry based on the input signal and the timer output signal.

6. Circuitry according to claim 1 , wherein the monitoring circuitry comprises:
voltage controlled oscillator (VCO) circuitry configured to generate an oscillating output signal having a frequency that is based on the supply voltage;
counter circuitry configured to:
receive the input signal and the oscillating output signal;
commence a count of cycles of the oscillating signal on detection of a feature of the input signal; and
output a counter output signal when the count reaches a count value that represents a magnitude of the supply voltage; and

logic circuitry configured to receive the input signal and the counter output signal and to generate a modified input signal for the PWM circuitry based on the input signal and the timer output signal.

7. Integrated circuitry comprising the circuitry of claim 1 .

8. A system comprising the circuitry of claim 1 and an output transducer configured to receive the digital output signal from the digital circuitry, wherein the output transducer comprises one or more of a motor, a light emitting diode (LED) or LED array, a haptic actuator, a resonant actuator and/or a servo.

9. A device comprising the circuitry of claim 1 , wherein the device comprises a battery powered device, a computer game controller, a virtual reality (VR) or augmented reality (AR) device, eyewear, a mobile telephone, a tablet or laptop computer, an accessory device, headphones, earphones or a headset.

10. A system comprising:
a plurality of driver circuits, each configured to output a drive signal for driving a respective one of a plurality of loads, wherein each drive signal is based on an input signal; and
a controller configured to control a parameter of one or more of the drive signals to compensate, at least partially, for a change in a component of the system.

11. A system according to claim 10 , wherein the parameter of the one or more of the drive signals comprises a pulse width or a pulse amplitude of a digital drive signal output by the one or more of the plurality of driver circuits.

12. A system according to claim 10 , wherein the system further comprises a power supply for providing a supply voltage to each of the plurality of driver circuits, wherein the change in the component of the system comprises a change in the supply voltage.

13. A system according to claim 12 , wherein the power supply comprises a battery, and wherein the change in the component of the system comprises a change in a parameter of the battery, wherein the parameter of the battery comprises one or more of:
an output voltage of the battery;
a state of charge of the battery;
a state of health of the battery; and
a temperature of the battery.

14. A system according to claim 10 , wherein the system further comprises a voltage regulator, wherein the change in the component of the system comprises a change in an output voltage of the voltage regulator.

15. A system according to claim 10 , wherein the change in the component of the system comprises one or more of:
a change in a parasitic element of the system;
a change in temperature of a component; and
a change in a parameter of an input signal.

16. A system according to claim 10 , wherein the controller is configured to estimate, calculate or otherwise determine a predicted power demand of each drive signal based on one or more parameters of the system.

17. A system according to claim 16 , wherein the one or more parameters of the system comprise:
an amplitude level of the input signal on which the drive signal is based;
a characteristic of a load driven by the drive signal;
a transient gradient for estimation of inrush current;
a frequency;
an average power; and/or
a transducer efficiency.

18. Circuitry comprising:
one or more driver signal paths, each associated with a load, for supplying a drive signal to the load; and
lookahead circuitry configured to:
receive signal data from a driver signal path;
estimate a power demand of a load coupled to the driver signal path based on the signal data and/or a characteristic of the load;
predict a future supply voltage based, at least in part, on the estimated power demand and a power supply parameter; and
based on the predicted future supply voltage, adjust a parameter of a signal in one or more of the driver signal paths.

19. Circuitry according to claim 18 , wherein the power supply parameter comprises one or more of:
a measure of a current battery supply level;
a supply decoupling capacitance; and
battery RC dynamics.

20. Circuitry according to claim 19 , wherein the battery RC dynamics are based on a battery parameter, the battery parameter comprising one or more of:
a state of charge;
a state of health; and
a temperature.

Assignees

• Cirrus Logic Int Semiconductor Ltd
• Cirrus Logic Inc

Inventors

• Morgan Ross C
• Rashid Tahir
• Taylor Jonathan

Classifications

• H02J7/855

  with circuits adapted for supplying loads from the battery · CPC title

• H02J7/96 Primary

  in response to battery voltage · CPC title

• H02M3/156

  with automatic control of output voltage or current, e.g. switching regulators · CPC title

• H02P7/29 Primary

  using pulse modulation · CPC title

• H03K7/08

  Duration or width modulation {; Duty cycle modulation} · CPC title