Texas Instruments CC1020, Руководство пользователя

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CC1020
www.ti.com SWRS046H – NOVEMBER 2006 – REVISED MARCH 2015
Table 6-2. Bill of Materials for the Application Circuit In Figure 6-1
(1) (2)
ITEM 433 MHz 868 MHz 915 MHz
C1
(3)
10 pF, 5%, NP0, 0402 47 pF, 5%, NP0, 0402 47 pF, 5%, NP0, 0402
C3
(3)
5.6 pF, 5%, NP0, 0402 10 pF, 5%, NP0, 0402 10 pF, 5%, NP0, 0402
C4 22 pF, 5%, NP0, 0402 22 pF, 5%, NP0, 0402 22 pF, 5%, NP0, 0402
C5 12 pF, 5%, NP0, 0402 12 pF, 5%, NP0, 0402 12 pF, 5%, NP0, 0402
C6 220 nF, 10%, X7R, 0603 100 nF, 10%, X7R, 0603 100 nF, 10%, X7R, 0603
C7 8.2 nF, 10%, X7R, 0402 3.9 nF, 10%, X7R, 0402 3.9 nF, 10%, X7R, 0402
C8 2.2 nF, 10%, X7R, 0402 1.0 nF, 10%, X7R, 0402 1.0 nF, 10%, X7R, 0402
C60 220 pF, 5%, NP0, 0402 220 pF, 5%, NP0, 0402 220 pF, 5%, NP0, 0402
L1
(3)
33 nH, 5%, 0402 82 nH, 5%, 0402 82 nH, 5%, 0402
L2
(3)
22 nH, 5%, 0402 3.6 nH, 5%, 0402 3.6 nH, 5%, 0402
R1 82 k Ω , 1%, 0402 82 k Ω , 1%, 0402 82 k Ω , 1%, 0402
R2 1.5 k Ω , 5%, 0402 2.2 k Ω , 5%, 0402 2.2 k Ω , 5%, 0402
R3 4.7 k Ω , 5%, 0402 6.8 k Ω , 5%, 0402 6.8 k Ω , 5%, 0402
R10 82
Ω
, 5%, 0402 82
Ω
, 5%, 0402 82
Ω
, 5%, 0402
14.7456 MHz crystal, 14.7456 MHz crystal, 14.7456 MHz crystal,
XTAL
16 pF load 16 pF load 16 pF load
(1) The PLL loop filter component values in Table 6-2 (R2, R3, C6-C8) can be used for data rates up to 4.8 kBaud.
(2) The SmartRF Studio software provides component values for other data rates using the equations in Section 5.12.2 .
(3) Items shaded vary for different frequencies. For 433 MHz, 12.5 kHz channel, a loop filter with lower bandwidth is used to improve
adjacent and alternate channel rejection.
In the CC1020EMX reference design ( CC1020EMX ), LQG15HS series inductors from Murata have been
used. The switch is SW-456 from M/A-COM.
The LC filter in Figure 6-1 is inserted in the TX path only. The filter will reduce the emission of harmonics
and the spurious emissions in the TX path. An alternative is to insert the LC filter between the antenna
and the T/R switch as shown in
Figure 6-2 .
The filter will reduce the emission of harmonics and the spurious emissions in the TX path as well as
increase the receiver selectivity. The sensitivity will be slightly reduced due to the insertion loss of the LC
filter.
6.2 Design Requirements
6.2.1 Input and Output Matching
L1 and C1 are the input match for the receiver. L1 is also a DC choke for biasing. L2 and C3 are used to
match the transmitter to 50
Ω . Internal circuitry makes it possible to connect the input and output together
and match the CC1020 to 50 Ω in both RX and TX mode. However, it is recommended to use an external
T/R switch for optimum performance. See Section 5.11 for details. Component values for the matching
network are easily found using the SmartRF Studio software.
6.2.2 Bias Resistor
The precision bias resistor R1 is used to set an accurate bias current.
6.2.3 PLL Loop Filter
The loop filter consists of two resistors (R2 and R3) and three capacitors (C6 through C8). C7 and C8 may
be omitted in applications where high loop bandwidth is desired. The values shown in
Table 6-2 can be
used for data rates up to 4.8 kBaud. Component values for higher data rates are easily found using the
SmartRF Studio software.
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