Abstract: A transconductor circuit, including a differential transconductor amplifier circuit. The transconductor circuit includes an input pair of transistors adapted to receive a differential input voltage, as well as a pair of output terminals adapted to provide a differential output current. A second pair of transistors provides current to the input pair of transistors. A floating voltage circuit is adapted to generate a floating voltage corresponding to a common-mode voltage of the differential output nodes and to control the second pair of transistors in response to the floating voltage to stabilize the common-mode voltage of the differential transconductor amplifier circuit.

Abstract: Techniques which allow a bit value stored/generated by integrated circuits to be changed by changing potentially only one of several masks used to fabricate the circuits. For example, when a single mask is to be re-designed to implement a design change (e.g., to fix minor bugs) and a version identifier is to be changed, the same mask can be used to implement the change in the version identifier as well. An embodiment allows the bit value to be changed any number of times by changing only one mask. As a result, the invention minimizes the number of masks that may need to be changed when implementing design changes.

Abstract: A filter circuit uses a trans-conductor circuit coupled to a control circuit having similar characteristics as the trans-conductor circuit. The control circuit is used to set and/or control the quiescent voltage of the trans-conductor circuit. As a result, the trans-conductor circuit may be designed to operate across a large frequency range while consuming minimal power. The control circuit may be operated using direct current (dc) voltage and may be implemented similar to the trans-conductor circuit implemented in the filter circuit.

Abstract: EMI caused on a sensitive pin by large electric current flowing through a load pin when driving a high load is reduced or substantially eliminated. An equal amount of current, but in opposite direction, is caused to be flown in another pin (“third pin”) located close to the load pin. As a result, the EMI caused by the third pin cancels the EMI generated by the load pin. During a discharge phase, a fourth pin carries and equal amount of current, but in opposite direction, to that in the load pin. The third and fourth pins may be formed by power supply pin and ground pin. A control path may avoid a path from the third pin to the fourth pin during both the charging and discharging phases. In addition, the high load may be driven by a programmable driver which uses an amount of current proportionate to the extent of load, thereby avoiding parasitic currents. EMI is further reduced as a result.

Abstract: A filter circuit uses a trans-conductor circuit coupled to a control circuit having similar characteristics as the trans-conductor circuit. The control circuit is used to set and/or control the quiescent voltage of the trans-conductor circuit. As a result, the trans-conductor circuit may be designed to operate across a large frequency range while consuming minimal power. The control circuit may be operated using direct current (dc) voltage and may be implemented similar to the trans-conductor circuit implemented in the filter circuit.

Abstract: The current passing in a main trans-conductor circuit is compared in analog domain with a reference current. If the passing current exceeds the reference current, another trans-conductor circuit may be switched on to cause the effective area of trans-conductor circuits to be increased. Using such a feature, the trans-conductance value may be maintained substantially constant without substantially increasing power.

Abstract: A capacitor current sensing circuitry (100) for sensing the current through a bandpass capacitor (20) of a first biquad stage (80) and generating an output current in response. The capacitor current sensing circuitry (100) includes a differential input circuit comprising a transistor (123) and a transistor (124), a fixed current source (130), a variable current source (120), a variable current, source (122), an input current sink (126), a differential output circuit comprising a transistor (132) and a transistor (134), and a programmable output current sink (138). The differential input circuit receives an input sense voltage and generates a first input current, a second input current, a first output voltage, and a second output voltage in response. The fixed current source (130) generates a current that is used to provide a first current component to the first input current and a first current component to the second input current.

Abstract: A charge pump (10) having a current source (12) and a current sink (14) is provided. Current source (12) generates one of two output currents using current mirror (16) and switch (18). Switch (18) selects between the two outputs based on a signal from source control (20). Current sink (14) generates one of two currents using current mirrors (44) and (46), and switch (48). Switch (48) selects from two currents generated by current mirrors (44) and (46).