Abstract:
The present invention discloses pre-amplifier with a selectable threshold voltage in a decision feedback equalization circuit to reduce tap weight variation. A decision feedback equalization circuit includes a summer circuit and a pre-amplifier with an offset generator, wherein the pre-amplifier includes a pair of differential amplifiers and each biased by a respective current bias and each having first and second output nodes coupled to a supply voltage via a respective resistive element, R. The resistive elements may be implemented, for example, using diode-configured transistors, biased transistors, resistor, or any other active or passive circuitry for establishing a resistance. The inputs of first differential amplifier are coupled to the summer's output. The inputs of second differential amplifier are coupled to a reference voltage circuit that comprised of a resistive element and a respective current DAC (IDAC).
Abstract:
A programmable current mirror a reference transistor, first and second mirror transistors, and a first current bypass. The reference transistor has a source and a gate coupled to a reference current node. The first and second mirror transistors are coupled together in series at a first node. Each of the first and second mirror transistors having gates coupled to each other and to the gate of the reference transistor. The first current bypass including a switch disposed in parallel with the second mirror transistor. The first current bypass is coupled to a source and a drain of the second mirror transistor and to the first node.
Abstract:
A programmable current mirror a reference transistor, first and second mirror transistors, and a first current bypass. The reference transistor has a source and a gate coupled to a reference current node. The first and second mirror transistors are coupled together in series at a first node. Each of the first and second mirror transistors having gates coupled to each other and to the gate of the reference transistor. The first current bypass including a switch disposed in parallel with the second mirror transistor. The first current bypass is coupled to a source and a drain of the second mirror transistor and to the first node.