ADF4112BRUZ Analog Devices Inc, ADF4112BRUZ Datasheet - Page 23

• Manufacturer Part Number: ADF4112BRUZ
• Description: IC SYNTH PLL RF 3.0GHZ 16-TSSOP
• Manufacturer: Analog Devices Inc
• Type: Clock/Frequency Synthesizer (RF)r

Specifications of ADF4112BRUZ

• Pll: Yes
• Input: Clock
• Output: Clock
• Number Of Circuits: 1
• Ratio - Input:output: 2:1
• Differential - Input:output: Yes/No
• Frequency - Max: 3GHz
• Divider/multiplier: Yes/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: 3GHz
• Pll Type: Frequency Synthesis
• Frequency: 3GHz
• Supply Current: 6.5mA
• Supply Voltage Range: 2.7V To 5.5V
• Digital Ic Case Style: TSSOP
• No. Of Pins: 16
• Operating Temperature Range: -40°C To +85°C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: EVAL-ADF4112EBZ1 - BOARD EVAL FOR ADF4112EVAL-ADF411XEBZ1 - BOARD EVAL FOR ADF411X NO CHIP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

USING A D/A CONVERTER TO DRIVE THE R
A D/A converter can be used to drive the R
ADF4110 family, thus increasing the level of control over the
charge pump current, I
band applications where the sensitivity of the VCO varies over
the tuning range. To compensate for this, the I
to maintain good phase margin and ensure loop stability. See
Figure 34.
SHUTDOWN CIRCUIT
The attached circuit in Figure 35 shows how to shut down both
the ADF4110 family and the accompanying VCO. The ADG701
switch goes closed circuit when a Logic 1 is applied to the IN
input. The low cost switch is available in both SOT-23 and
MSOP packages.
WIDEBAND PLL
Many of the wireless applications for synthesizers and VCOs in
PLLs are narrow band in nature. These applications include the
various wireless standards like GSM, DSC1800, CDMA, and
WCDMA. In each of these cases, the total tuning range for the
local oscillator is less than 100 MHz. However, there are also
wideband applications for which the local oscillator could have
FREF
CP
. This can be advantageous in wide-
IN
2.7kΩ
SPI COMPATIBLE SERIAL BUS
8
1
CE
CLK
DATA
LE
V-OUT DAC
REF
R
SET
AD5320
12-BIT
ADF4111
ADF4112
ADF4113
IN
SET
MUXOUT
CP
pin of the
RF
RF
Figure 34. Driving the R
may be varied
IN
IN
CP
A
B
14
2
6
5
SET
100pF
PIN
LOCK
DETECT
100pF
POWER SUPPLY CONNECTIONS AND DECOUPLING
CAPACITORS ARE OMITTED FOR CLARITY.
Rev. C | Page 23 of 28
51Ω
FILTER
SET
LOOP
Pin with a D/A Converter
a tuning range as wide as an octave. For example, cable TV
tuners have a total range of about 400 MHz. Figure 36 shows an
application where the ADF4113 is used to control and program
the Micronetics M3500-2235. The loop filter was designed for
an RF output of 2900 MHz, a loop bandwidth of 40 kHz, a PFD
frequency of 1 MHz, I
multiplied by the gain factor of 4), VCO K
(sensitivity of the M3500-2235 at an output of 2900 MHz), and
a phase margin of 45°C.
In narrow-band applications, there is generally a small variation
in output frequency (generally less than 10%) and a small
variation in VCO sensitivity over the range (typically 10% to
15%). However, in wideband applications, both of these
parameters have a much greater variation. In Figure 36, for
example, there is a −25% and +17% variation in the RF output
from the nominal 2.9 GHz. The sensitivity of the VCO can vary
from 120 MHz/V at 2750 MHz to 75 MHz/V at 3400 MHz
(+33%, −17%). Variations in these parameters change the loop
bandwidth. This in turn can affect stability and lock time. By
changing the programmable I
tion for these varying loop conditions and ensure that the loop
is always operating close to optimal conditions.
ADF4110/ADF4111/ADF4112/ADF4113
INPUT OUTPUT
GND
VCO
CP
of 10 mA (2.5 mA synthesizer I
100pF
CP
100pF
18Ω
, it is possible to get compensa-
18Ω
18Ω
RF
OUT
D
of 90 MHz/V
CP