文档介绍：LOW POWER CMOS FULLY DIFFERENTIAL
VARIABLE-GAIN AMPLIFIER
S. Spiridon, F. Op't Eynde
AsicAhead International SRL, Bucharest, Romania
Abstract-This paper presents the design, analyses In paragraph II, the VGA architecture- is
and measurement results of a fast differential presented. In order to optimize promise
variable-gain amplifier (VGA) intended for high- between Power Consumption and GBW, a seven
speed data streaming applications such as the IEEE stage approach is chosen. Each stage has a
wireless LAN. The circuit is a seven stage
amplifier that offers a programmable gain in the programmable gain of 6 or 12 dB. In paragraph
0 . 84 dB range, in 6 dB steps. Each stage has a III the fully differential opamp is described, with
programmable gain of either 6 dB or 12 dB. Fully emphasis on mon mode feedback.
differential low power opamntps are used. With an Further on, the simulation results are presented
opamp gain-bandwidth product (GBW) of about 200 And finally, in Section IV, the circuit layout
MHz, the input frequency can go as high as 10 MHz. and measurement results are shown. This proves
Offset filtering is possible with a high pass filter with that the design specifications are met and that the
programmable 3 dB frequency. The circuit operates VGA can be essfully incorported in a Wireless
at only V, making it an ideal choice for low-power re