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dc1660bf
DEMO MANUAL DC1660B
Description
LTC6417
1.6GHz Low Noise Differential
16-Bit ADC Buffer
Demonstration circuit 1660B features the LTC
®
6417 dif-
ferential 16-bit ADC buffer. The demo board incorporates a
variety of passive components to allow for direct connec-
tion to a two-port network analyzer or other single-ended
50Ω test system.
The demo board is easily configured to control common-
mode voltage V
CM
, clamp voltage CLHI, power adjust
PWRADJ, and SHUTDOWN pins. Other simple PCB modifi-
cations can accommodate differential input/output signals.
Design files for this circuit board are available at
http://www.linear.com/demo
L
, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.
Quick start proceDure
DC1660B is easy to set up to evaluate the performance of
the LTC6417. Refer to Figure 1 for proper measurement
equipment setup and follow the procedure below:
1. Connect SMA cables to IN
+
and OUT
+
ports.
2. Apply 5.0V between V
+
and GND turrets.
Tie PWRADJ (TURRET E4) to V
+
. Limit supply current
to approximately 150mA.
3. V
CM
, CLHI and SHDN turrets may be left floating.
This procedure contains a critical sequence. The user
must apply supply voltage before applying signal power
to the inputs or forcing a voltage to any other turrets. The
user must also remove the signal from the input ports
and voltages on any other turret before turning down
the supply voltage. This proper sequence will prevent
excessive current through the ESD diodes from any pin
to the positive supply V
+
. Table 1 shows the function of
each SMA connector on the board. Only J1, J3 and J5
are used in the default configuration. J2 and J4 provide
flexibility for differential input/output signals.
Table 1. DC1660B SMA Connectors
CONNECTOR
FUNCTION
J1 (IN
+
)
Differential input connected to input balun for single-
ended operation. Drive from a 50Ω signal source.
No external termination needed.
J2 (IN
–
)
Differential Input. Not connected by default. Remove
capacitor C12 to drive the input balun differentially.
J3 (OUT
+
)
Differential output connected to balun for single-ended
operation. Connect to a 50Ω network/spectrum
analyzer input.
J4 (OUT
–
)
Differential Output. Not connected by default. Remove
capacitor C11 to drive the input balun differentially.
J5 (OR)
Overrange Output. Connect to oscilloscope for
monitoring the output signal.
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