US 11,949,321 B2
Pre-biased mode switching in system having selectable pulse-width modulated (PWM) and linear operation
Vamsikrishna Parupalli, Austin, TX (US); Nishant Jain, Austin, TX (US); and Mengde Wang, Austin, TX (US)
Assigned to CIRRUS LOGIC, INC., Austin, TX (US)
Filed by CIRRUS LOGIC INTERNATIONAL SEMICONDUCTOR LTD., Edinburgh (GB)
Filed on Oct. 26, 2021, as Appl. No. 17/510,707.
Prior Publication US 2023/0128810 A1, Apr. 27, 2023
Int. Cl. H02P 27/00 (2006.01); H02M 1/00 (2006.01); H02M 1/088 (2006.01); H02M 3/28 (2006.01); H02P 27/08 (2006.01)
CPC H02M 1/0045 (2021.05) [H02M 1/088 (2013.01); H02P 27/08 (2013.01)] 24 Claims
OG exemplary drawing
 
1. An electronic system providing selectable driving of a load in either a pulse-width modulated operating mode or a linear operating mode, the electronic system comprising:
an output stage for supplying current to the load, the output stage having a push-pull driver provided by a P-channel transistor coupled between a power supply rail and the load and an N-channel transistor coupled between a power supply return and the load;
a mode selection control circuit for selecting between the pulse-width modulated operating mode and the linear operating mode as a selected operating mode;
a pulse-width modulator output driver for providing pulse-width modulated drive signals generated from one or more quantizer output signals to a gate of the P-channel transistor and a gate of the N-channel transistor, respectively, while the selected operating mode is the pulse-width modulated operating mode;
a linear amplifier stage for providing linear analog signals to the gates of the P-channel transistor and the N-channel transistor while the selected operating mode is the linear mode; and
a pre-charging circuit having outputs coupled to the gates of the P-channel transistor and the N-channel transistor and responsive to the mode selection control circuit for pre-charging the gates of the P-channel transistor and the N-channel transistor during a pre-charge cycle initiated when the mode selection control circuit changes the selected operating mode to the linear operating mode, wherein during the pre-charge cycle, the pulse-width modulated drive signals are not applied to the gate of the P-channel transistor and the gate of the N-channel transistor, so that the outputs of the pre-charging circuit are independent of the one or more quantizer output signals, and wherein the linear analog signals are applied to the gates of the P-channel transistor and the N-channel transistor along with the outputs of the pre-charging circuit.