Cirrus Logic Inc.

Mengde Wang

Vamsikrishna Parupalli

Eric B Smith

Saurabh Singh

Mark May

Nishant Jain

Ramya Balasundaram

Akhilesh Persha

An electronic control system provides selectable linear and pulse-width modulated (PWM) operation with reduced disruption when changing from PWM operation to linear operation. The system includes an output stage that has a push-pull driver coupled to the load, which may be a motor, a haptic device, or other device requiring current-mode control. The system also includes a pulse-width modulated (PWM) driver for providing pulse-width modulated drive signals to gates of the transistors of the output stage when a pulse-width modulated mode is selected, and a linear amplifier stage that provides a linear analog signal to the gates of the transistors when a linear mode is selected. A pre-charging circuit pre-charges the gates during a pre-charge cycle that is initiated when the operating mode changes from the PWM operating more to the linear operating mode.

Pre-biased mode switching in system having selectable pulse-width modulated (PWM) and linear operation

A system may include an output stage for driving a load at an output of the output stage, a pulse-width modulation mode path configured to pre-drive the output stage in a first mode of operation, a linear mode path configured to pre-drive the output stage in a second mode of operation and a loop filter coupled at its input to the output of the output stage and coupled at its output to both of the pulse-width modulation mode path and the linear mode path. The pulse-width modulation mode path and the linear mode path may be configured such that a first transfer function between the output of the loop filter and the output of the output stage is substantially equivalent to a second transfer function between the output of the loop filter and the output of the output stage.

Closed loop control in a camera module

A system may include a driver for driving an output signal to a load, a pre-driver for driving a pre-driver signal to the driver, the pre-driver having a variable drive strength, and a controller configured to control the variable drive strength based on at least one measured physical quantity to compensate for variation of an output signal edge rate due to variations in the at least one measured physical quantity.

Controlling edge rate of a switched output stage based on a measured physical quantity

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Mengde Wang