Dc2609A Reconfiguration - Analog Devices LTC6952 Demo Manual

DC2609A RECONFIGURATION

The following covers the hardware reconfiguration of the
DC2609A. Refer to LTC6952Wizard and the LTC6952 data
sheet to better understand how to change programmed
parameters on the DC2609A.
LTC6952 3.3V POWER SUPPLY OPTIONS
Table 1 provides the 3.3V power supply options for
DC2609A. By default the DC2609A is setup to use the
LDO only supply option. An alternative jumper select-
able supply option is provided that uses an LDO and
Silent Switcher supply. The LDO + Silent Switcher option
powers the higher current LTC6952 output supply pins
from an LTC Silent Switcher, such as the LT8609S. The
LTC Silent Switcher improves the power efficiency over
the low noise LDO. A low noise LDO is required on the
+
LTC6952's V and V
VCO REF
in-band performance.
Table 1. Power Supply Options
Default Option
X LDO Only
LDO + Silent Switcher
VCO SMA: INPUT TERMINATION OPTIONS
Table 2 provides the single-ended and differential SMA
input termination options. By default the DC2609A is
setup for onboard VCO input and does not use the J28
and J29 SMAs.
Table 2. VCO SMA Input Termination Options (*)
SMA Termination R18
Inputs Ω
–
J28 SE, IN 75
+
J29 SE, IN 30
J28 & DIFF , CML or DNI
J29 PECL
DIFF , LVDS DNI
* SE = Single-Ended, DIFF = Differential, DNI = Do Not Install
+
supply pins for acceptable
Jumper Settings
JP4 JP6 JP7
2-3 1-2 2-3
1-2 1-2 1-2
R22 R20 R21 C14 C16
Ω Ω Ω µF
30 DNI DNI 0.1 DNI
75 DNI DNI DNI 0.1
DNI 160 DNI 0.1 0.1
DNI DNI 160 0.1 0.1
DEMO MANUAL DC2609A
LTC6952 6952SET FILES
The LTC6952Wizard provides a 6952set file for all
LTC6952 data sheet application examples and typical
application circuits. After loading a 6952 set file a pop-up
window will detail any user actions and board modifica-
tions required for the selected file.
SYNC OPTIONS
The LTC6952 data sheet describes several synchroniza-
tion modes. After selecting the desired synchronization
mode, refer to Table 3 to identify the required DC2609A
board modifications. Refer to the LTC6952 data sheet for
SYNC timing and level requirements.
CML OUTPUTS, OUT[10:0]
The DC2609A has 11 CML outputs. OUT[9:0] have match-
ing trace lengths, which are optimized for skew measure-
ments. OUT10's trace lengths are longer than the other
outputs traces due to the shape of the DC2609A.
Six of these outputs are AC-coupled and brought out to
SMAs (OUT9, OUT8, OUT5, OUT4, OUT1, and OUT0). To
drive 50Ω impedance instruments connect OUTx
instrument and OUTx
The remaining five outputs (OUT10, OUT7, OUT6, OUT3,
and OUT2) are terminated with a 100Ω resistor onboard.
To connect these outputs to a 50Ω instrument, remove
the 100Ω termination, and install the appropriate SMAs
and AC blocking capacitors.
Refer to LTC6952 data sheet for differential termination
options.
µF
–
to a 50Ω termination, or vice versa.
+
to the
Rev 0
5