Systems, methods, and apparatus for use in biasing and driving high voltage semiconductor devices using only low voltage transistors are described. The apparatus and method are adapted to control multiple high voltage semiconductor devices to enable high voltage power control, such as power amplifiers, power management and conversion (e.g. DC/DC) and other applications wherein a first voltage is large compared to the maximum voltage handling of the low voltage control transistors. According to an aspect, timing control of edges of a control signal to the high voltage semiconductor devices is provided by a basic edge delay circuit that includes a transistor, a current source and a capacitor. An inverter can be selectively coupled, via a switch, to an input and/or an output of the basic edge delay circuit to allow for timing control of a rising edge or a falling edge of the control signal.

An integrated circuit includes at least one differential pair of transistors, a bias current generator that is configured to generate a bias current on a bias node that is coupled to a source terminal of each transistor of said differential pair by a respective resistive element. A compensation current generator is configured to generate a compensation current in one of the two resistive elements so as to compensate for a difference between actual values of the threshold voltages of the transistors of said differential pair.

Various examples related to electromagnetic interference (EMI) energy mitigation techniques are provided. In one example, a method includes determining electromagnetic interference (EMI) spectrum information based upon switching angles of a switching circuit and processing harmonic magnitudes (C.sub.i) associated with the switching angles using an artificial neural network to determine adjusted switching angles for the switching circuit; and applying the adjusted switching angles to control the switching circuit thereby reducing generated EMI energy by the switching circuit.

Various examples related to electromagnetic interference (EMI) energy mitigation techniques are provided. In one example, a method includes determining electromagnetic interference (EMI) spectrum information based upon switching angles of a switching circuit and processing harmonic magnitudes (C.sub.i) associated with the switching angles using an artificial neural network to determine adjusted switching angles for the switching circuit; and applying the adjusted switching angles to control the switching circuit thereby reducing generated EMI energy by the switching circuit.

A common mode voltage level shifting and locking circuit is provided. The common mode voltage level shifting and locking circuit includes an operational amplifier, a source follower, a first feedback circuit, and a second feedback circuit. The operational amplifier generates a first common mode voltage. The source follower shifts the first common mode voltage to generate a second common mode voltage. The first feedback circuit generates a first control signal according to the second common mode voltage. The operational amplifier adjusts the first common mode voltage according to the first control signal. The second feedback circuit generates a second control signal according to an external reference voltage provided by a next stage circuit. The source follower adjusts the second common mode voltage according to the second control signal such that the next stage circuit reaches a maximum input common mode range.

A wide band communications circuit buffer can include a pair of NPN bipolar transistor emitter followers deployed as a voltage buffer and disposed at inputs before and outputs after an equalization module, and a pair of diode connected NPN transistors deployed as a level shifter and disposed following the emitter followers before an output of the wide band driver to keep an output level at the output of the wide band buffer close to a desired level. Resistors connected between emitters and a V.sub.EE terminal can be used to further adjust the DC level. An LC tank filter can be provided between emitters of the voltage buffer components and the circuit's outputs to pass and boost high frequency signals provided to next stage components. The wide band buffer is, inter alia, appropriate for use in providing a DC level shift function as used in wired data communication systems circuitry.

A wide band communications circuit buffer can include a pair of NPN bipolar transistor emitter followers deployed as a voltage buffer and disposed at inputs before and outputs after an equalization module, and a pair of diode connected NPN transistors deployed as a level shifter and disposed following the emitter followers before an output of the wide band driver to keep an output level at the output of the wide band buffer close to a desired level. Resistors connected between emitters and a V.sub.EE terminal can be used to further adjust the DC level. An LC tank filter can be provided between emitters of the voltage buffer components and the circuit's outputs to pass and boost high frequency signals provided to next stage components. The wide band buffer is, inter alia, appropriate for use in providing a DC level shift function as used in wired data communication systems circuitry.

A signal coupling method and apparatus is disclosed. A coupling network is coupled to convey signals from first functional circuit block to a second functional circuit block. The coupling network includes a first signal path having a first capacitor for providing AC coupling between the first and second functional circuit blocks. The coupling network further includes a second signal path in parallel with the first signal path. The second signal path includes a switched capacitor circuit coupled to receive a first common mode voltage corresponding to the first functional circuit block and a second common mode voltage corresponding to the second functional circuit block.

A signal coupling method and apparatus is disclosed. A coupling network is coupled to convey signals from first functional circuit block to a second functional circuit block. The coupling network includes a first signal path having a first capacitor for providing AC coupling between the first and second functional circuit blocks. The coupling network further includes a second signal path in parallel with the first signal path. The second signal path includes a switched capacitor circuit coupled to receive a first common mode voltage corresponding to the first functional circuit block and a second common mode voltage corresponding to the second functional circuit block.

A DC-shifting predriver has an input port configured for coupling to a serial data stream, an inverting output amplifier having an feedback node and an output port configured for coupling to a transistor at the input to a high-speed DAC or TX driver, and a capacitor AC-coupled between the input port and the feedback node. A weak feedback inverter having structure similar to, but less drive strength than the inverting output amplifier is coupled between the output port and the feedback node to act as a positive feedback latch. The predriver provides a DC shift up to 3V with high reliability and minimal intersymbol interference for data rates from 10 GS/s to 28 GS/s or higher. The predriver may provide multiple input ports implemented as a predriver array in an M-bit system, and the output amplifier may consist of N stages.