Transducer built-in self-test
AssigneeQUALCOMM Technologies, Inc.
InventorMichael Carfore
Life of this patent
Estimating the term…
Abstract
An apparatus for testing a transducer module includes a test signal generator coupled to a common-mode terminal common to a plurality of transducers, and a signal processing circuit configured to receive output signal from each of said transducers and to produce an output signal. If the transducers are well matched to one another, the output signal will have little or no output amplitude. If there is a mismatch between the transducers, however, the output signal will have an amplitude proportional to the mismatch. The amplitude of the output signal may be compared to a predetermined threshold in order to produce a mismatch output signal indicating the existence of, and/or the degree of, mismatch between the transducers.
Claims16
A method for testing a system, comprising:
- providing a transducer module having:
- a plurality of transducers having a common-mode terminal, each transducer configured to independently produce corresponding output signal, relative to the common-mode terminal, in response to a common stimulus, and
- a transducer output interface comprising a plurality of transducer output terminals, each transducer output terminal corresponding to a one of the plurality of transducers and configured to provide corresponding output signal;
- providing a transducer signal amplifier input interface comprising a plurality of amplifier input terminals, each amplifier input terminal of the plurality of amplifier input terminals operably coupled to a corresponding one of the transducer output terminals, and a transducer signal amplifier output interface configured to provide a transducer signal amplifier output signal having an amplifier output amplitude;
- injecting a conditioned alternating signal into the common mode terminal, the conditioned alternating signal being an electrical signal having an injected amplitude;
- and
- determining whether the plurality of transducers are not well matched by;
- comparing the transducer signal amplifier output signal to a pre-determined mismatch threshold.
An apparatus for testing a transducer module having a plurality of transducers, the plurality of transducers having a common-mode terminal, each transducer configured to independently produce corresponding output signal relative to the common-mode terminal in response to a common stimulus, the apparatus comprising:
- a test signal generator configured to generate an alternating test signal having a test signal amplitude, the test signal generator having a test signal output terminal configured to provide the test signal from the test signal generator to the common-mode terminal of the transducer module;
- a signal processing circuit configured to process transducer output signals from the transducer module, the signal processing circuit having an interface comprising:
- a first signal processing input terminal configured to receive a first transducer output;
- a second signal processing input terminal configured to receive a second transducer output;
- a signal processing circuit output configured to produce a system output signal based on the first transducer output and the second transducer output;
- a controller configured to controllably couple the test signal to the common-mode terminal of the transducer module in a test mode;
- and
- an output comparator coupled to receive the system output signal and configured to produce, in the test mode, a comparator output signal indicating that the system output signal indicates a mismatch between the first transducer output and the second transducer output.
Dependencies are inferred from the claim text.