SI4200-GM Silicon Laboratories Inc, SI4200-GM Datasheet - Page 22

• Manufacturer Part Number: SI4200-GM
• Description: IC TXRX TRI-BAND 32MLP
• Manufacturer: Silicon Laboratories Inc

Specifications of SI4200-GM

• Frequency: 850MHz, 900MHz, 1.8GHz
• Modulation Or Protocol: GSM
• Applications: Cellular, GSM Cellular Radio
• Voltage - Supply: 2.7 V ~ 3.3 V
• Data Interface: PCB, Surface Mount
• Antenna Connector: PCB, Surface Mount
• Package / Case: 32-VQFN Exposed Pad, 32-HVQFN, 32-SQFN, 32-DHVQFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Power - Output: -
• Operating Temperature: -
• Sensitivity: -
• Memory Size: -
• Data Rate - Maximum: -
• Current - Transmitting: -
• Current - Receiving: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

Aero+
VCO Inductor Design
Determining L
The center frequencies for the RF2, and IF VCOs in the
Si4134T are set using an external inductance (L
is very important that L
ensure maximum manufacturing margin for the desired
VCO frequency tuning ranges. Because the total tank
inductance is in the low nH range, the inductance of the
package (L
correct external inductance.
Figure 15 shows the detailed configuration of the
integrated VCOs. The total inductance (L
VCO is the sum of the external inductance (L
the package inductance (L
(C
capacitance (C
(C
capacitance (C
C
values are defined in Table 7 on page 14.
The center frequency is calculated as follows:
The value for the external inductor is determined by the
following:
where f
22
TUNE
TOT
VAR
) of each VCO is the sum of the self tuning
), and the fixed capacitance (C
and C
C
L
L
CEN
PKG
EXT
NOM
PKG
f
VAR
CEN
L
= desired center frequency of VCO.
= nominal capacitance from Table 7.
= package inductance from Table 7.
= external inductance required.
EXT
EXT
) must be considered in determining the
NOM
TUNE
at their center values. C
=
=
) of each VCO is calculated with
------------------------------------------------------------------ -
2π C
), the PLL varactor capacitance
------------------------------------------- - L
(
2πf
PLL
CEN
EXT
NOM
PKG
1
)
2
(
be properly designed to
C
L
1
). The total capacitance
PKG
NOM
C
VAR
+
Tune
–
Self
FIX
L
Figure 15. VCO Block Diagram
EXT
PKG
). The nominal
NOM
)
TOT
C
) of each
and L
TUNE
EXT
EXT
) and
PKG
). It
Rev. 1.2
C
For example, the RF2 VCO for a triple-band design
requires f
C
The previous equation shows L
connected between the RFLC and RFLD pins.
See “AN49: Aero Transceiver PCB Layout Guidelines”
for details on how to implement and verify the proper
value of L
FIX
Supported Bands
European Dual-Band (900/1800)
Triple-Band (900/1800/1900)
Quad-Band (850/900/1800/1900)
or North American Dual Band
(850/1900)
*Note: L
Supported Bands
European Dual-Band (900/1800)
Triple-Band (900/1800/1900)
Quad-Band (850/900/1800/1900) or
North American Dual Band (850/1900)
NOM
= 4.8 pF and L
AMP
EXT
Table 9. VCO f
Table 10. VCO L
CEN
EXT
IC
is set internally.
.
= 1381 MHz. Table 7 on page 14 shows
PACKAGE BOARD
Si4134T
L
L
PKG
PKG
/2
/2
PKG
CEN
= 2.02 nH for the RF2 VCO.
L
EXT
EXT
Values (MHz)
EXT
Values (nH)
= 0.75 nH should be
RF1*
VCO
1862 1341 782
1897 1381 810
1864 1378 831
VCO
0.91
0.75
0.76
RF2
VCO
RF2
VCO
4.77
4.34
4.04
VCO
IF
IF