mga-635t6 Avago Technologies, mga-635t6 Datasheet - Page 5

• Manufacturer Part Number: mga-635t6
• Description: Gps Low Noise Amplifer With Variable Bias Current And Shutdown Function
• Manufacturer: Avago Technologies

Figure 5. Demoboard schematic diagram
Notes
1. L1 and L2 form the input matching network. The LNA module has a built-in coupling and DC-block capacitor at the input and output. Best noise
2. L3 is an output matching inductor.
3. C1 is a RF bypass capacitor.
4. PRL1 is a network that isolates the measurement demoboard from external disturbances. C2 and C3 mitigates the effect of external noise pickup
5. Bias control is achieved by either varying the VSD voltage without R1 or fixing the VSD voltage to VDD and varying R1. Typical value for R1 is
Vs d = +2.85V
Vs d = +2.85V
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performance is obtained using high-Q wirewound inductors. This circuit demonstrates that low noise figures are obtainable with standard 0402
chip inductors. Replacing L1, L2 and L3 with high-Q wirewound inductors (eg. Cilcraft 0402CS series) will yield 0.1dB lower NF and 0.2dB higher
Gain.
on the VSD and VDD lines. These components are not required in actual operation.
22k Ohm for 5mA total current at VDD=+2.85V.
RF_IN
RF_IN
C
C
C2
C2
C=6.8 pF
C=6.8 pF
R
R
R1
R1
R=22
L
L
L1
L1
L=5.6 nH
L=5.6 nH
Toko 0402
Toko 0402
kOhm
L
L
L2
L2
L=12 nH
L=12 nH
Toko 0402
Toko 0402
2
2
C
C
C3
C3
C=0.1 uF
C=0.1 uF
C
C
4
4
BIAS
BIAS
C
C
C1
C1
C=6.8 pF
C=6.8 pF
Amplifie r2
Amplifie r2
AMP 1
AMP 1
6
6
Toko 0402
Toko 0402
L
L
L3
L3
L=6.8 nH
L=6.8 nH
R=
R=
Vdd = +2.85V
Vdd = +2.85V
Toko 0402
Toko 0402
P RL
P RL
P RL1
P RL1
R2 =12 Ohm
R2 =12 Ohm
L4 =33 nH
L4 =33 nH
C
C
GND
GND
RF_OUT
RF_OUT
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