A low-poswer wide-band amplifier using a new parasitic capacitance compensation technique

A low-power. wide-band amplifier is needed for a tuner IC. a synthesizer LSI and an cqualizing amplifier IC fa optical fiber transmission systems. Parasitic capacitance is the major factor limiting the band-width, especially for low-power amplifiers. To enhance the band-width, a negative feedback[ll or peaking technique [Z] is Widely used. However. these techniques enhance the band-width with the degraded voltage gain, because the gain band-width product is not enhanced with these techniques. Moreover, a peakmg technique requires additional power to adjust the peaking characteristics. In this paper. a new parasitic capacitance compensation technique that enhances both the band-width and the gain band-width product is proposed. Using this technique, a 3-mW 8w-MHz amplifier wilh a voltage gain of 10 dB has bcen achieved. This band-width is about 40 percent wider than that of a differential amplifier using a pealdng technique.