US 12,257,601 B2
Driver circuitry and operation
Axel Thomsen, Austin, TX (US); Eric J. King, Austin, TX (US); Anthony S. Doy, Los Gatos, CA (US); Thomas H Hoff, Austin, TX (US); and John L. Melanson, Austin, TX (US)
Assigned to Cirrus Logic Inc., Austin, TX (US)
Filed by Cirrus Logic International Semiconductor Ltd., Edinburgh (GB)
Filed on Mar. 25, 2024, as Appl. No. 18/615,241.
Application 18/615,241 is a continuation of application No. 18/323,779, filed on May 25, 2023, granted, now 11,980,913.
Application 18/323,779 is a continuation of application No. 17/314,890, filed on May 7, 2021, granted, now 11,684,950, issued on Jun. 27, 2023.
Claims priority of provisional application 63/065,051, filed on Aug. 13, 2020.
Prior Publication US 2024/0226960 A1, Jul. 11, 2024
This patent is subject to a terminal disclaimer.
Int. Cl. B06B 1/02 (2006.01); B06B 1/06 (2006.01); G06F 3/01 (2006.01); H10N 30/80 (2023.01)
CPC B06B 1/0223 (2013.01) [B06B 1/0215 (2013.01); B06B 1/0688 (2013.01); G06F 3/016 (2013.01); H10N 30/802 (2023.02)] 19 Claims
OG exemplary drawing
 
1. A driver circuit for driving a transducer based on an input signal comprising:
a switching output stage having first and second output nodes for driving said transducer in a bridge-tied-load configuration; and
a controller configured to control the switching output stage based on the input signal so as to modulate each of the first and second output nodes between a respective pair of switching voltages at a respective duty cycle in a switching cycle,
wherein the controller is operable in at least:
a first mode in which the first output node is modulated between a first pair of switching voltages and the second output node is modulated between a second pair of switching voltages; and
a second mode in which the first output node is modulated between a third pair of switching voltages and the second output node is modulated between said second pair of switching voltages, wherein at least one of the switching voltages of the third pair of switching voltages is different to a switching voltage of the first pair of switching voltages;
wherein the controller is configured to transition between the first mode and the second mode by:
applying a variation in the duty cycle of modulation of the second output node between the second pair of switching voltages; and
within a switching cycle of applying said variation in the duty cycle of modulation of the second output node, changing the modulation of the first output node from the first pair of switching voltages to the third pair of switching voltages or vice versa.