Abstract: A signal shaping circuit for use in a transmission line driver and the like is disclosed. The input is pulse signal having a rising edge that triggers a delay circuit which produces a first sequence of multiple delayed outputs and a falling edge which triggers the delay circuit to produce a second sequence of multiple delayed outputs. Transition control circuitry is included which operates to control the transition time of the output signal in a first direction, such as the rise time, in response to the first sequence of multiple delayed outputs and to control the transition time of the output signal in a second direction, such as the fall time, in response to the second sequence of multiple delayed outputs. By controlling the first and second delayed output, the rise and fall times of the output signal can be precisely controlled.

Abstract: A current amplifier driver capable of driving both 10 Base-T signalling and 100 Base signalling in a Local Area Network (LAN) includes one constant current source. A voltage controlled switch is contained in each of four vertical segment of an H-bridge circuit. Two voltage signals are applied to the switches to control the direction of current from a constant current source across a load. When one of the voltage signals is high, the other is low and two switches of the four switches turn on. The current amplifier driver sinks the constant current in a first direction, such that a voltage drop across the output nodes is positive. When the other voltage signal is high the switches that were on turn off, and the other two switches turn on to sink the constant current across the load in the opposite direction, such that a voltage drop across the output nodes is negative. When both voltage signals are low, all four switches turn off, and the output voltage is zero.

Abstract: A stacked current mirror circuit includes four N-channel MOS transistors. One transistor serves as an input device for conducting via its drain, a majority of the reference current. Another transistor is connected as a mirroring device, with its drain coupled to a voltage source, its gate coupled to the gate of the input device, and its source coupled to the source of the input device at a first common node. These two transistors couple to form a first current mirror circuit which couples to the input of a second current mirror comprising the third and fourth transistors. The drain and gate of the third transistor couple to the first common node and the gate of the fourth transistor. The sources of both the third and fourth transistors couple to a second common node (e.g., ground), and the drain of the fourth transistor provides the output. As a result, current is mirrored from the input device transistor to the mirroring device transistor, and then forced through the third transistor.

Abstract: A current mode driver capable of driving both 10 Base-T signalling and 100 Base-T signalling in a Local Area Network (LAN) includes two or four current sources. In a first embodiment, a differential signal generator drives four current sources. The generator outputs four signals, one of which is received by each current source. Using these signals, two of the current sources push or pull current across the load in one direction, while the other two current sources push or pull current across the load in the other direction, such that a full differential signal is generated across the load. In another embodiment, a signal generator drives two current sources which drive into the load one at a time. Two switches provide either high resistance or low resistance during half of a signal cycle such that current is pulled through the load in one direction, and prevented from flowing through the load in the other direction.