Datasheet
ADL5315
Rev. 0 | Page 15 of 20
05694-028
R
INPUT
FET BUFFER
VECTOR SIGNAL
ANALYZER
HP89410A
ADL5315
VPOS SREF VSET
+12V
–12V
INPT IOUT
R
LOAD
2.2nF
LNA
1.5V
+
–
+
–
1.5V
9V
+
–
1.5V
+
–
–
+
9V
Figure 31. Configuration for Noise Spectral Density and Wideband Current Noise
Figure 32 shows the configuration used to measure the pulse
response of I
INPT
to I
OUT
. To create the test current pulse, Q1 is
used in a common base configuration with the Agilent 33250A
pulse generator. The output of the 33250A is a negative biased
square wave with an amplitude that results in a one decade
current step at I
OUT
.
R
C
is chosen according to what current range is desired. For
30 µA and lower, the
AD8067 FET input op amp is used in a
transimpedance amplifier configuration to allow for viewing on
the TDS5104 oscilloscope. For signals greater than 30 µA, the
ADA4899-1 replaced the AD8067 to avoid limiting the
bandwidth of the ADL5315.
The configuration in
Figure 33 is used to measure V
INPT
while
V
SET
is pulsed. Q1 and R
C
are used to generate the operating
current on the INPT pin. An Agilent 33250A pulse generator is
used on the VSET pin to create a 0.0 V to 4.0 V square wave.
The setup in
Figure 34 was used to measure the small signal ac
response from I
INPT
to I
OUT
. The AD8138 differential amplifier
was used to couple the ac and dc signals together. The ac signal
was modulated to a depth of 5% of full scale over frequency.
The voltage across R
F
sets the dc operating point of I
INPT
. The
values of R
F
are chosen to result in decade changes in I
INPT
. The
ADA4899-1 op amp is used as a transimpedance amplifier for
all current conditions.
TDS5104
OSCILLOSCOPE
ADL5315
EVALUATION BOARD
INPT
VPOS VSET SREF COMM
IOUT
DC SUPPLIES/DMM
R
C
R
C
AGILENT 33250A
PULSE GENERATOR
Q1
05694-024
Figure 32. Configuration for Pulse Response of I
INPT
to I
OUT
05694-026
R
C
Q1
TDS5104
OSCILLOSCOPE
ADL5315
EVALUATION BOARD
VPOS SREF COMM
IOUT
DC SUPPLIES/DMM
INPT
VSET
AGILENT 33250A
PULSE GENERATOR
KEITHLEY 236
Figure 33. Configuration for Pulse Response from V
SET
to V
INPT
NETWORK ANALYZER
OUTPUT R BA
POWER
SPLITTER
AD8138
EVAL BOARD
++
––
ADL5315
EVALUATION BOARD
INPT
50Ω
05694-027
IOUT
R
F
R
F
VPOS VSET SREF COMM
DC SUPPLIES/DMM
Figure 34. Configuration for Small-Signal AC Response