
18
FN957.10
July 11, 2005
+15V
3
0.1
μ
F
8
5k
7
1
5
6
2
R
2
R
1
10k
R
3
1N914
10k
100k
OFFSET
ADJUST
4
PEAK
ADJUST
10k
+
CA3140
-
20V
P-P
Input BW (-3dB) = 290kHz, DC Output (Avg) = 3.2V
GAIN
R
2
R
1
------
X
R
1
2
3
-----------------+
=
=
=
R
3
----+
2
–
1
R
1
=
FOR X
0.5
--------------
R
2
R
1
------
=
=
R
3
10k
-----------
15k
=
=
OUTPUT
0
INPUT
0
FIGURE 26. SINGLE SUPPLY, ABSOLUTE VALUE, IDEAL
FULL WAVE RECTIFIER WITH ASSOCIATED
WAVEFORMS
+15V
-15V
2
7
4
+
CA3140
-
3
0.01
μ
F
0.01
μ
F
6
1M
NOISE VOLTAGE
OUTPUT
30.1k
1k
R
S
BW (-3dB) = 140kHz
TOTAL NOISE VOLTAGE
(REFERRED TO INPUT) = 48
μ
V (TYP)
FIGURE 27. TEST CIRCUIT AMPLIFIER (30dB GAIN) USED FOR
WIDEBAND NOISE MEASUREMENT
Top Trace: Output; 50mV/Div., 200ns/Div.
Bottom Trace: Input; 50mV/Div., 200ns/Div.
FIGURE 28B. SMALL SIGNAL RESPONSE
(Measurement made with Tektronix 7A13 differential amplifier.)
Top Trace: Output Signal; 5V/Div., 5
μ
s/Div.
Center Trace: Difference Signal; 5mV/Div., 5
μ
s/Div.
Bottom Trace: Input Signal; 5V/Div., 5
μ
s/Div.
FIGURE 28C. INPUT-OUTPUT DIFFERENCE SIGNAL SHOWING
SETTLING TIME
FIGURE 28. SPLIT SUPPLY VOLTAGE FOLLOWER TEST
CIRCUIT AND ASSOCIATED WAVEFORMS
+15V
-15V
2
7
4
+
CA3140
-
3
0.1
μ
F
0.1
μ
F
6
0.05
μ
F
2k
10k
100pF
SIMULATED
LOAD
2k
BW (-3dB) = 4.5MHz
SR = 9V/
μ
s
FIGURE 28A. TEST CIRCUIT
INPUT
CA3140, CA3140A