A wideband current amplifier with DC-offset cancellation utilizing chopper modulation
- 46 Downloads
A wideband current amplifier with DC-offset cancellation utilizing chopper modulation is proposed. Combining series–series feedback with backgate driven choppers, a wideband current amplifier with DC-offset cancellation is realized. As consumed a power of 1.495 mW under a supply voltage of 1.8 V, measured bandwidth of the current amplifier is 120 MHz, which leads the current amplifier can be adopted to compose the analog baseband of a wideband direct-conversion receiver with bandwidth of 240 MHz (twice of the baseband bandwidth). Measured current gain of the current amplifier is 15 dB. Measured output DC-offset without and with DC-offset cancellation are − 70.8 dBV and − 91 dBV, respectively. Thus, DC-offset reduction of 20 dB is achieved.
KeywordsCurrent amplifier DC-offset cancellation Chopper modulation Analog baseband Wideband Receiver
This study was funded by Ministry of Science and Technology, Taiwan.
- 2.Koli, K., & Halonen, K. (2002). CMOS current amplifiers (p. 2). Boston, MA: Kluwer Academic.Google Scholar
- 4.Menolfi, C., & Huang, Q. (1999). A chopper modulated instrumentation amplifier with first order low-pass filter and delayed modulation scheme. In European solid-state circuits conference (ESSCIRC’99) (pp. 54–57).Google Scholar
- 5.Rogin, J., Kouchev, I., & Huang, Q. (2003). A 1.5 V 45 mW direct conversion WCDMA receiver IC in 0.13 µm CMOS. In IEEE international solid-state circuits conference (ISSCC) (pp. 268–493).Google Scholar
- 8.Yuan, F. (2007). CMOS current-mode circuits for data communications (p. 6). New York: Springer.Google Scholar