A unity gain amplifier of the Diamond follower type provides the combination of negligible input offset voltage, high slew rate, and high bandwidth by providing first and second opposite polarity current mirror circuits which respond to currents flowing through first and second input transistors to boost current available to charge parasitic capacitances during fast rise times and fast fall times of an input pulse. The rapid charging and discharging of the parasitic capacitances eliminates degradation in the rise and fall times of an output pulse produced by the unity gain amplifier.
5170134 - Fast buffer - Owned by SGS-Thomson Microelectronics, Inc. (Carrollton, TX)
A buffer circuit includes an input amplifier connected to receive an input signal and an output amplifier connected provide an output signal. A differential amplifier is connected to also receive the input and output signals and to provide an output related to the difference between the signals to maintain a desired relationship between the input and output signals. The buffer circuit can be configured so that the signal from the differential amplifier is provided either to the input or the output amplifier, and can be accomplished in either bipolar or BICMOS technologies. The combination of the open loop and differential type buffer amplifiers, retains the best features of both, with the excellent speed performance of the open loop circuit as well as the enhanced accuracy of the differential amplifier circuit.
A circuit for multiplexing a selected one of a plurality of input signals to an output conductor includes a plurality of diamond follower input buffers each having an input terminal coupled to receive an input signal, respectively. A diamond follower output buffer has an output coupled to the output conductor. A feedback resistor is coupled between the output conductor and the outputs of the input buffers. A first current mirror has a control input coupled to a first current bias terminal of each input buffer, and a second current error has a control input coupled to a second current bias terminal of each input buffer. The first and second current mirrors have outputs connected to drive the input of the output buffer and bias current terminals of the output buffer to provide a high slew rate.
