ADC input circuit sensing for fault detection
AssigneeAnalog Devices International Unlimited Company
InventorsMichal Brychta, Adrian Sherry
Life of this patent
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Abstract
A fault detection scheme can include use of a relatively high injection impedance between an input port for analog measurements from a sensor and a stimulus generation circuit controlled in coordination with analog measurement. The stimulus generation circuit can provide a stimulus signal through the injection impedance. A magnitude of the injection impedance can be specified relative to a source impedance associated with a source (e.g., a sensor or other device) coupled to the input port. For example, a magnitude of the injection impedance can be specified to be larger than the source impedance or the injection impedance magnitude can be specified to be a multiple of the source impedance.
Claims20
An electronic system equipped to detect a fault in a signal path coupled to an input port of the electronic system, the electronic system comprising:
- an analog measurement circuit configured to receive a signal from a source coupled to the input port, the analog measurement circuit comprising an analog-to-digital converter (ADC) circuit configured to provide a digital representation of the received signal from the source, the analog measurement circuit including a divider circuit configured to scale the signal from the source for presentation to an input of the ADC;
- a stimulus generation circuit coupled to the input port through an injection impedance including a resistor, the injection impedance having a value greater in magnitude than a source impedance associated with the source;
- control circuitry coupled to the analog measurement circuit and the stimulus generation circuit, the control circuitry configured to:
- control the stimulus generation circuit to generate a pulsed stimulus signal for fault detection;
- receive a representation of the pulsed stimulus signal using the analog measurement circuit;
- and
- determine whether a fault exists in the signal path coupled to the input port at least in part using information about a magnitude of the representation of the pulsed stimulus signal received from the analog measurement circuit.
An electronic system, equipped to detect a fault in a signal path coupled to an input port of the electronic system, the electronic system comprising:
- an analog measurement circuit configured to receive a signal from a source coupled to a differential input comprising first and second input terminals, the analog measurement circuit comprising resistor divider circuits for each of the first and second input terminals, the resistor divider circuits configured to scale the signal from the first and second input terminals for presentation to the ADC;
- stimulus generation outputs coupled to the first and second input terminals through respective injection impedances comprising resistors;
- control circuitry coupled to the analog measurement circuit, the control circuitry configured to:
- control the stimulus generation outputs to generate a pulsed stimulus signal comprising respective signal components coupled to the first and second input terminals;
- receive a representation of the pulsed stimulus signal using the analog measurement circuit;
- and
- determine whether a fault exists in a signal path coupled to the input port at least in part using information about a magnitude of the representation of the pulsed stimulus signal received from the analog measurement circuit.
A method for detecting a fault in a signal path coupled to an input port of an electronic system, the method comprising
- using an analog measurement circuit, receiving a signal from a source coupled to an input port of the analog measurement circuit through a divider circuit configured to scale the signal from the source for presentation to an analog-to-digital (ADC) converter circuit included as a portion of the analog measurement circuit;
- injecting a pulsed stimulus signal through an injection impedance, including a resistor, into the signal path, the injection impedance having a value greater in magnitude than a source impedance associated with the source;
- receiving a representation of the pulsed stimulus signal using the analog measurement circuit;
- and
- determining whether a fault exists in the signal path coupled to the input port at least in part using information about a magnitude of the received representation of the pulsed stimulus signal from the analog measurement circuit.
Dependencies are inferred from the claim text.