UG-806
EVAL-CN0369SDPZ User Guide
Rev. 0 | Page 4 of 8
EVALUATION BOARD HARDWARE
TRANSATION LOOP SYNTHESIZER
The translation loop synthesizer (also known as an offset loop) as
the name implies, translates the lower 100 MHz reference freq-
uency of the
phase locked loop (PLL) up to a higher
frequency range of 5.0 GHz to 5.4 GHz, as determined by the
frequency of the local oscillator (LO). Figure 2 shows a translation
loop evaluation setup using the
POWER SUPPLIES
The user must apply 5.5 V to the VSUPPLY_5V5 power
connectors (4 mm banana connectors) and +12 V to the SMA
connector l12VOLTS. The POWER on-board LED
indicates when the
is powered.
JUMPERS
Table 1 shows the required positions for Jumper LK1 and
Jumper LK2 for normal operation.
Table 1. Jumper Positions
Jumper
Position
LK1
Inserted
LK2
B—normal operation
A—hardware power-down
Jumper LK1 inserted enables the LOCK DETECT on-board LED.
RF OUTPUTS
The radio frequency (RF) output (VCO/2) and the fundamental
VCO output (EXT_VCOOUT1) are ac-coupled to VCO/2 and
EXT_VCOOUT1 SMA connectors, respectively. Set the RF
output coupling to the spectrum analyzer must be set to 50 Ω.
ACTIVE LOOP FILTER AND CHARGE PUMP
CURRENT
The default active loop filter is set to 1.1 MHz. Using a charge
pump setting of 5 mA is recommended.
REFERENCE SOURCE AND FINE TUNING
An external reference using the REFIN SMA is the default
reference source and fine tuning for the
provided by the
initially program the
to generate 100 MHz
RF output frequency. Achieve fine tuning of the translation loop
by changing the
output frequency incremen-
tally. A loop bandwidth of 100 kHz is recommended to allow the
to provide the fine tuning required. Insert a low pass
filter between the SMA connector of the
and the REFIN SMA connector of the
to filter the harmonics created by the output dividers. Terminate
the unused RFOUTB− SMA connector on the
The RFOUTBx SMA connector gives higher output power in
comparison to RFOUTAx for lower output frequencies as it uses
a higher value of pull-up inductor. Refer to the
user guide for details on evaluation board set-up and
programming.
RFIN AND RF_MIXER AND COURSE TUNING
mixer evaluation board and a low noise
signal generator provides the translation loop coarse tuning
requirement.
Connect the low noise signal generator to the LO input of the
. Connect the RF_MIXER SMA connector
. Connect the intermediate frequency (IF) output of the
to the RFIN SMA connector of the
via a 400 MHz low pass filter. Consult the
data sheet for details on using and connecting the
evaluation board.
for a block diagram of the test setup of
the
To evaluate the
, initially program the
signal generator to output 5.2 GHz with a power level of 0 dBm.
Achieve coarse tuning of the translation loop by changing the
output of the signal generator in increments of 100 MHz from
5.3 GHz to 4.9 GHz.
