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Avago’s MGA-72543 is an economical, easy-to-use GaAs
MMIC Low Noise Amplifer (LNA),which is designed for an
adaptive CDMA receiver LNA and adaptive CDMA transmit
driver amplifer.
The MGA-72543 features a minimum noise fgure of 1.4 dB
and 14 dB associated gain from a single stage, feedback
FET amplifer. The output is internally matched to 50Ω.
The input is optimally internally matched for lowest noise
fgure into 50Ω. The input may be additionally externally
matched for low VSWR through the addition of a single
series inductor. When set into the bypass mode,both input
and output are internally matched to 50Ω.
The MGA-72543 ofers an integrated solution of LNA with
adjustable IIP3. The IIP3 can be fxed to a desired current
level for the receiver’s linearity requirements. The LNA has
a bypass switch function,which sets the current to zero
and provides low insertion loss. The bypass mode also
boosts dynamic range when high level signal is being
received.
For the CDMA driver amplifer applications, the MGA-
72543 provides suitable gain and linearity to meet the
ACPR requirements when the handset transmits the
highest power. When transmitting lower power, the MGA-
72543 can be bypassed, saving the drawing current.
The MGA-72543 is a GaAs MMIC, processed on Avago’s
cost efective PHEMT (Pseudomorphic High Electron Mo-
bility Transistor). It is housed in the SOT343 (SC70 4-lead)
package, and is part of the Avago Technologies CDMAd-
vantage RF chipset.