Abstract: A mode selection amplifier circuit has multiple differential amplifier circuits coupled to receive input signals A, B and C. Each differential amplifier circuit is selectively operable for generating a signal output representative of an output mode with the output mode of each differential amplifier circuit selected from one of algebraic combinations of the signal inputs A?C, B?C, A?B and (A+B)/2?C. The mode selection amplifier circuit is usable in a signal acquisition probe for providing various signal output modes to a measurement test instrument.

Abstract: A mode selection amplifier circuit has multiple differential amplifier circuits coupled to receive input signals A, B and C. Each differential amplifier circuit is selectively operable for generating a signal output representative of an output mode with the output mode of each differential amplifier circuit selected from one of algebraic combinations of the signal inputs A?C, B?C, A?B and (A+B)/2?C. The mode selection amplifier circuit is usable in a signal acquisition probe for providing various signal output modes to a measurement test instrument.

Abstract: An integrated circuit includes a termination for a transmission line having a predetermined characteristic impedance. The termination includes a controllable impedance circuit, including a multiplier, coupled to the transmission line. A reference impedance, placed external to the integrated circuit, has an impedance related to the characteristic impedance of the transmission line.

Abstract: A low capacitance probe tip and socket for a measurement probe has a probe tip extending through an insulating plug and a recess defining a socket formed in the plug. The socket has an aperture formed therein that provides access the low capacitance probe tip. An electrically conductive contact is disposed in the aperture that extends into the socket and is in electrical contact with the low capacitance probe tip. In one embodiment, the socket is formed parallel to the low capacitance probe tip. In a further embodiment, the socket is formed at an angle to the low capacitance probe tip with the electrically conductive contact being an electrically conductive elastomeric material disposed at the distal end of the socket in electrical contact with the low capacitance probe tip.

Abstract: An integrated circuit includes a termination for a transmission line having a predetermined characteristic impedance. The termination includes a controllable impedance circuit, including a multiplier, coupled to the transmission line. A reference impedance, placed external to the integrated circuit, has an impedance related to the characteristic impedance of the transmission line.

Abstract: A low capacitance probe tip and socket for a measurement probe has a probe tip extending through an insulating plug and a recess defining a socket formed in the plug. The socket has an aperture formed therein that provides access the low capacitance probe tip. An electrically conductive contact is disposed in the aperture that extends into the socket and is in electrical contact with the low capacitance probe tip. In one embodiment, the socket is formed parallel to the low capacitance probe tip. In a further embodiment, the socket is formed at an angle to the low capacitance probe tip with the electrically conductive contact being an electrically conductive elastomeric material disposed at the distal end of the socket in electrical contact with the low capacitance probe tip.

Abstract: A probe adapter for coupling probe tip contacts of a electrical measurement probe to leads of a surface mounted integrated circuit IC device has an insulating housing from which extend first and second flexible electrically conductive leads having a pitch geometry compatible with the leads of the IC device. First and second electrical contacts, respectively coupled to the first and second flexible electrically conductive leads, are disposed in the housing and have a pitch geometry compatible with the probe tip contacts of the electrical measurement probe.

Abstract: A high-frequency calibration method and circuit including a dual path step attenuator. A calibration system is provided having a switch between the user signal input and the instrument input and an amplifier between the calibration signal input and the instrument input. The amplifier provides signal conditioning. The output of the amplifier is connected to the instrument input through a switch and a resistor, the resistor isolating the switch from the instrument input so as effectively to prevent degradation of the user input signal. A sense amplifier provides a calibration signal output indicative of the input impedance of the instrument input in response to a known stimulus. The input of the sense amplifier is isolated from the instrument input by a resistor. A current source provides a known stimulus to the instrument input to measure input impedance. A step attenuator is provided having an attenuated path and an unattenuated path.

Abstract: A high-frequency calibration method and circuit including a dual path step attenuator. A calibration system is provided having a switch between the user signal input and the instrument input and an amplifier between the calibration signal input and the instrument input. The amplifier provides signal conditioning. The output of the amplifier is connected to the instrument input through a switch and a resistor, the resistor isolating the switch from the instrument input so as effectively to prevent degradation of the user input signal. A sense amplifier provides a calibration signal output indicative of the input impedance of the instrument input in response to a known stimulus. The input of the sense amplifier is isolated from the instrument input by a resistor. A current source provides a known stimulus to the instrument input to measure input impedance. A step attenuator is provided having an attenuated path and an unattenuated path.