ADF4350
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
24
23
22
21
20
19
18
17
V
V
R
A
CLK
DATA
LE
CE
SW
1
2
REF
PIN 1
COM
INDICATOR
3
4
SET
ADF4350
GNDVCO
5
6
7
8
V
TOP VIEW
TUNE
V
P
OUT
(Not to Scale)
TEM
A
V
P
CP
GNDVCO
VCO
CP
GND
NOTES
1. THE LFCSP HAS AN EXPOSED PADDLE THAT MUST BE CONNECTED TO GND.
Figure 3. Pin Configuration
Table 4. Pin Function Descriptions
Pin No.
Mnemonic Description
1
CLK
DATA
LE
Serial Clock Input. Data is clocked into the 32-bit shift register on the CLK rising edge. This input is a high
impedance CMOS input.
Serial Data Input. The serial data is loaded MSB first with the three LSBs as the control bits. This input is a high
impedance CMOS input.
Load Enable, CMOS Input. When LE goes high, the data stored in the shift register is loaded into the register
that is selected by the three LSBs.
Chip Enable. A logic low on this pin powers down the device and puts the charge pump into three-state mode.
A logic high on this pin powers up the device depending on the status of the power-down bits.
2
3
4
CE
5
6
SW
VP
Fast-Lock Switch. A connection should be made from the loop filter to this pin when using the fast-lock mode.
Charge Pump Power Supply. This pin is to be equal to AVDD. Decoupling capacitors to the ground plane are to
be placed as close as possible to this pin.
7
CPOUT
Charge Pump Output. When enabled, this provides ICP to the external loop filter. The output of the loop filter is
connected to VTUNE to drive the internal VCO.
8
9
10
CPGND
AGND
AVDD
Charge Pump Ground. This is the ground return pin for CPOUT
Analog Ground. This is a ground return pin for AVDD.
Analog Power Supply. This pin ranges from 3.0 V to 3.6 V. Decoupling capacitors to the analog ground plane are
to be placed as close as possible to this pin. AVDD must have the same value as DVDD.
.
11, 18, 21
AGNDVCO
VCO Analog Ground. These are the ground return pins for the VCO.
12
13
RFOUTA+
RFOUTA−
VCO Output. The output level is programmable. The VCO fundamental output or a divided down version is available.
Complementary VCO Output. The output level is programmable. The VCO fundamental output or a divided
down version is available.
14
RFOUTB+
RFOUTB−
VVCO
Auxilliary VCO Output. The output level is programmable. The VCO fundamental output or a divided down
version is available.
Complementary Auxilliary VCO Output. The output level is programmable. The VCO fundamental output or a
divided down version is available.
Power Supply for the VCO. This ranges from 3.0 V to 3.6 V. Decoupling capacitors to the analog ground plane
should be placed as close as possible to these pins. VVCO must have the same value as AVDD.
Temperature Compensation Output. Decoupling capacitors to the ground plane are to be placed as close as
possible to this pin.
15
16, 17
19
TEMP
VTUNE
20
Control Input to the VCO. This voltage determines the output frequency and is derived from filtering the CPOUT
output voltage.
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