Patent ID: 6353366
Filing Date: 2002-03-05
Classification: H03F

Abstract:
A bandwidth enhancement method by adding a peaking capacitor to a transimpedance amplifier for creating peaking effect, comprising:providing a transimpedance amplifier composed of an inverting amplifier including an inverter having an output, a resistive feedback loop, and an output buffer stage, and a 3-dB bandwidth peaking capacitor added to the transimpedance amplifier parallel with the output of the inverter to ground for creating a 3-dB bandwidth peaking effect in high frequency band to thereby expand and double the bandwidth of the transimpedance amplifier; and, wherein one more pole is available in transfer function than that of a transimpedance amplifier without an extra capacitor; a Q value may be controlled and the bandwidth may be broadened by proper selection of said peaking a capacitor; in case the Q value is greater than 0.5, the correspondent form of said pole is in complex conjugates, and the imaginary parts will be cancelled to broaden the bandwidth; or, if the Q value exceeds to 0.707, a maximum frequency response results; and, the peaking effect occurs when the Q value is greater than 0.707; therefore, the value of Q may be controlled by selecting said peaking capacitor for adjustment of the bandwidth of said transimpedance amplifier.