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

Claim 0:
1. An electronic motor control system, comprising:
an output stage for supplying the current to the motor, the output stage having a first push-pull driver coupled to a first output for coupling to a first terminal of the motor and a second push-pull driver coupled to a second output for coupling to a second terminal of the motor;
a mode selection control circuit for selecting between a pulse-width modulated mode and a linear mode of the electronic motor controller;
a pulse-width modulator output driver for providing pulse-width modulated drive signals to an input of the output stage when the mode selection control circuit selects the pulse-width modulated mode, wherein the mode selection control circuit selects one of the first push-pull driver or the second push-pull driver in conformity with a direction of the current supplied to the motor, and wherein the selected one of the first push-pull driver or the second push-pull driver is pulse-width modulated and another one of the first push-pull driver or the second push-pull driver is operated to supply a fixed voltage when the mode selection control circuit selects the pulse-width modulated mode;
a linear amplifier stage for providing a linear analog signal to the input of the output stage when the mode selection control circuit selects the linear mode, wherein 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 supplied to the motor 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 when the mode selection control circuit selects the linear mode; and
a feedback control loop for sensing the current supplied to the motor and providing a first output to the pulse-width modulator and a second output to the linear amplifier 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 mode selection control circuit selecting the pulse-width modulated mode generates the first output to the pulse-width modulator 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 mode selection control circuit selecting the linear mode, the current monitor generates the second 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.