ADF4206BRU Analog Devices Inc, ADF4206BRU Datasheet - Page 21

• Manufacturer Part Number: ADF4206BRU
• Description: IC PLL FREQ SYNTHESIZER 16-TSSOP
• Manufacturer: Analog Devices Inc
• Type: Clock/Frequency Synthesizer (RF)r

Specifications of ADF4206BRU

• Rohs Status: RoHS non-compliant
• Pll: Yes
• Input: CMOS
• Output: Clock
• Number Of Circuits: 1
• Ratio - Input:output: 3:1
• Differential - Input:output: Yes/No
• Frequency - Max: 550MHz
• Divider/multiplier: No/No
• Voltage - Supply: 2.7 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 16-TSSOP
• Frequency-max: 550MHz

LOCAL OSCILLATOR FOR WCDMA RECEIVER
Figure 33 shows the ADF4208 used to generate the local
oscillator frequencies for a wideband CDMA (WCDMA)
system.
The required RF output range is 1720 MHz to 1780 MHz. The
VCO190-1750T meets this requirement. Channel spacing is
100pF
18Ω
18Ω
IF
OUT
DECOUPLING CAPACITORS (22µF/10pF) ON V
THE ADF4208, AND ON V
OMITTED FROM THE DIAGRAM TO AID CLARITY.
18Ω
100pF
51Ω
VCO190-200T
100pF
V
CC
CC
1.3nF
OF THE VCOs HAVE BEEN
30pF
30pF
Figure 33. Local Oscillator for WCDMA Receiver Using the ADF4208
2.7k
13nF
3.3kΩ
DD
10MHz
, V
P
620pF
18kΩ
OF
CP
Rev. A | Page 21 of 24
V
RF2
OSC
OSC
V
P
P
2
RF2
IN
IN
OUT
ADF4208
V
V
DD
DD
2 V
DD
200 kHz with a 20 kHz loop bandwidth. VCO sensitivity is
32 MHz/V. A charge pump current of 4.375 mA is used and the
desired phase margin for the loop is 45°.
When the IF output is fixed at 200 MHz, the VCO190-200T is
used. It has a sensitivity of 10 MHz/V. Channel spacing and
loop bandwidth are chosen to be the same as the RF side.
1
MUXOUT
CP
DATA
RF1
CLK
V
V
RF1
LE
P
P
IN
1
LOCK DETECT
V
VCO190-1750T
CC
100pF
ADF4206/ADF4208
100pF 18Ω
51Ω
100pF
RF
OUT
18Ω
18Ω