Synchronization circuit and method of performing synchronization
AssigneeCypress Semiconductor Corporation
InventorViktor Kremin
Life of this patent
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Abstract
The circuit comprises a pulse width modulated (PWM) input signal, a resistor, an instrumentation amplifier, a filter and an analog to digital converter. The method of performing synchronization comprises sampling an analog signal and forming a digital data stream representing the signal, filtering the data stream to remove harmonics, measuring an approximate level of ripple in the data stream, detecting a change in the level of ripple, and based upon change in the level of ripple, determining if a stall has occurred.
Claims21
A synchronization circuit, comprising:
- a pulse width modulated (PWM) input signal;
- an inverter having an input coupled to the pulse width modulated input signal;
- a first resistor tree coupled to an output of the inverter;
- an instrumentation amplifier having an input coupled to the first resistor tree,
- wherein the instrumentation amplifier is configured to measure a level of ripple in the PWM input signal;
- a filter coupled to an output of the instrumentation amplifier,
- wherein the filter is configured to detect a change in the measured level of the ripple, and
- wherein a motor stall is determined when the change in the measured level of the ripple exceeds a predetermined threshold;
- and
- an analog to digital converter coupled to an output of the filter.
A synchronization circuit, comprising:
- a pulse width modulated (PWM) input signal;
- a load coupled in series with the pulse width modulated input signal;
- an instrumentation amplifier having a first input coupled to the load,
- wherein the instrumentation amplifier is configured to measure a level of ripple in the PWM input signal;
- a resistor coupled between the first input and a second input of the instrumentation amplifier;
- a switch coupled to the second input of the instrumentation amplifier,
- wherein the switch is configured to select between a first voltage and a second voltage;
- a filter coupled to an output of the instrumentation amplifier,
- wherein the filter is configured to detect a change in the measured level of the ripple, and
- wherein a motor stall is determined when the change in the measured level of the ripple exceeds a predetermined threshold;
- and
- an analog to digital converter coupled to an output of the filter.
A method of performing synchronization, comprising:
- sampling an analog signal and forming a digital data stream representing the analog signal;
- filtering the digital data stream to remove harmonics;
- measuring an approximate level of ripple in the digital data stream;
- detecting a change in the measured level of ripple;
- and
- based upon the change in the measured level of ripple, determining if a motor stall has occurred.
A synchronization circuit for a motor, comprising:
- means for sampling an analog signal and forming a digital data stream representing the analog signal;
- means for filtering the digital data stream;
- means for measuring a level of ripple in the digital data stream;
- means for detecting a change in the measured level of ripple in the digital data stream;
- and
- means for determining if the motor has stalled based upon the change detected in the measured level of ripple.
Dependencies are inferred from the claim text.