MC13821 Freescale Semiconductor, MC13821 Datasheet - Page 11

• Manufacturer Part Number: MC13821
• Description: Low Noise Amplifier
• Manufacturer: Freescale Semiconductor

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Application information for 1575, 1960, 2140 and 2400 MHz are shown. For each application, two current
drain examples are provided. Typical RF performance is shown for two values of bias resistor R1: 1.2 kΩ
and 2 kΩ, see
intercept point, gain, and noise figure. For 1960 and 2140 MHz, additional application circuits are shown.
These demonstrate specific performance characteristics and utilize varying input and output matches and
different biasing resistors.
Measurements are made at a bias of V
Non-linear measurements are made at Pin = -30 dB. The board loss corrections for these boards are: Input
0.16 dB, Output 0.2 dB. Gain and NF results incorporate these corrections in order to better reflect the
actual performance of the device.
3.1
This application circuit was designed to provide NF < 1.2 dB, S21 gain > 18 dB, OIP3 of 18 dBm with
S11 better than -10 dB and S22 better than -10 dB at 1575 MHz with unconditional stability from 100 MHz
to 10 GHz. Typical performance that can be expected from this circuit at 2.75 V V
The component values can be changed to enhance the performance of a particular parameter, but usually
at the expense of another. Two variations of the circuit are realized for different requirements for IP3 and
I
Freescale Semiconductor
CC
. Values of external resistors R1 and R2 are varied to adjust I
1575 MHz Application
Table
Vcc1
LNA
OUT
6,
5.6 nH
.01uf
C5
L2
Table
C2
pf
1
33 pf
Vcc3
C6
7,
Figure 9. 1575 MHz LNA Application Schematic
33 pf
.01uf
C3
N
C
C4
Table
680
MC13821 Data Sheet: Technical Data, Rev. 1.5
R2
1
2
3
8, and
CC
= 2.75 V. Freq. spacing for IP3 measurements is 200 kHz.
Table
R1
2 k
Rbias
NC
12
4
9. These two current drain states offer variation in
1575 MHz
MC13821
LNA
NC
11
5
5.6 nH
L1
NC
10
6
CC
Logic
and IP3.
22pF
C1
LNA IN
9
8
7
CC
Gain
Enable
Gnd
is listed in
Application Information
Table
6.
11