Detecting amplifier out-of-range conditions
AssigneeTexas Instruments Incorporated
InventorsViola Schaffer, Mikhail Ivanov
Life of this patent
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Abstract
Out-of-range conditions are detected in amplifier CMOS or BiCMOS circuitry that includes a control transistor (MS) connected in series with a cascode transistor (MSC), and a differential amplifier (A1) with an inverting input connected to the node between the control transistor and the cascode transistor, a non-inverting input connected to a reference voltage source (VRDS) and an output connected to the gate of the cascode transistor (MSC). The voltage at the output of the differential amplifier (A1) is monitored, and an error condition is determined when the voltage exceeds or drops below a predetermined threshold value. The invention considerably widens the useful operating range, without requiring sophisticated or complex detection circuitry.
Claims6
A method of detecting out-of-range conditions in amplifier CMOS or BiCMOS circuitry that includes a control transistor connected in series with a cascode transistor, and a differential amplifier with an inverting input connected to a node between the control transistor and the cascode transistor, a non-inverting input connected to a reference voltage source and an output connected to a gate of the cascode transistor, comprising the step of monitoring the voltage at the output of the differential amplifier and determining an error condition when the voltage exceeds or drops below a predetermined threshold value.
An amplifier with CMOS or BiCMOS amplifier circuitry that includes a control transistor connected in series with a cascode transistor and a differential amplifier with an inverting input connected to a node between the control transistor and the cascode transistor, a non-inverting input connected to a reference voltage source and an output connected to a gate of the cascode transistor, the amplifier further comprising a voltage detector with an input connected to the output of the differential amplifier, the voltage detector providing an error output in response to the voltage at the output of the differential amplifier exceeding or dropping below a predetermined threshold value.
Dependencies are inferred from the claim text.