Patent ID: 11962261
Assignee: CIRRUS LOGIC INC.
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC G  H | IPC G  H

Claim 18:
19. An electronic motor control system, comprising:
an output stage for supplying the current to the motor and having a first push-pull driver and a second push-pull driver, wherein the output stage has outputs for coupling to terminals of the motor;
a drive stage for providing inputs to the push-pull drivers that operates in a pulse-width modulated mode or a linear mode, wherein, in the linear mode, the driver stage operates the output stage so that both the first push-pull driver and the second push-pull driver are operated in combination to supply the current to the motor by simultaneous conduction of the current through both the first push-pull driver and the second push-pull driver, so that the first push-pull driver and the second push-pull driver operate in combination as a class AB differential driver, and wherein in the pulse-width modulated mode, the drive stage operates the output stage so that one of the push-pull drivers has a pulse-width modulated output provided to a first terminal of the motor and another one of the push-pull drivers is turned fully-on in one polarity to provide a fixed voltage to the other terminal of the motor; and
a feedback control loop for sensing the current supplied to the motor and providing at least one output to the drive stage, wherein the feedback control loop includes a current monitor circuit that senses a first sink current conducted through the first push-pull driver and a second sink current conducted through the second push-pull driver, wherein the current monitor circuit, responsive to the drive stage operating in the pulse-width modulated mode, generates the at least one output from a selected one of the first sink current or the second sink current corresponding to the another one of the first push-pull driver or the second-push pull driver, whereby the selected one of the first sink current or the second sink current is the current returned from the motor, and wherein responsive to the drive circuit operating in the linear mode, the current monitor generates the at least one output from a difference between the first sink current and the second sink current to compensate for bias current flowing in the first push-pull driver and the second-push pull driver.