CA3140AS INTERSIL [Intersil Corporation], CA3140AS Datasheet - Page 16

• Manufacturer Part Number: CA3140AS
• Description: 4.5MHz, BiMOS Operational Amplifier with MOSFET Input/Bipolar Output
• Manufacturer: INTERSIL [Intersil Corporation]

back is provided by the 3k and 100k divider network con-
nected to the base of the current sensing transistor.
FIGURE 25. REGULATED POWER SUPPLY WITH “FOLDBACK”
+30V
+30V
(MEASUREMENT BANDWIDTH ~10MHz)
INPUT
INPUT
(MEASUREMENT BANDWIDTH ~10MHz)
HUM AND NOISE OUTPUT <200 VRMS
HUM AND NOISE OUTPUT <200 VRMS
LINE REGULATION 0.1%/VOLT
LINE REGULATION 0.1%/VOLT
10
10
3
9
8
9
8
6
FIGURE 24. REGULATED POWER SUPPLY
6
2.7k
2.7k
11
7
11
7
POWER DARLINGTON
CURRENT LIMITING
2.2k
2.2k
10 F
10 F
1
2N6385
100k
2
100
1
3
5
4
1
3
5
4
2N5294
“FOLDBACK” CURRENT
-
-
+
+
2
2
62k
62k
1
6
+
6
+
-
-
75
3k
100k
12
100k
12
LIMITER
3
5 F
CA3086
5 F
CA3086
1k
1k
5
5
100k
CA3140
CA3140
CURRENT
LIMITING
ADJUST
14
13
14
13
2
7
1
7
1
50k
50k
1k
1k
8
4
8
4
D2201
D2201
(NO LOAD TO FULL LOAD)
(NO LOAD TO FULL LOAD)
1k
2
3
1k
2
3
1k
1k
3k
200
56pF
56pF
LOAD REGULATION
LOAD REGULATION
VOLTAGE
VOLTAGE
1k
1k
ADJUST
ADJUST
2N2102
100k
2N2102
100k
0.01 F
0.01 F
2
OUTPUT
25V AT 1A
“FOLDS BACK”
TO 40mA
<0.02%
<0.02%
180k
180k
82k
82k
0.1
OUTPUT
1
3
AT 1A
CA3140, CA3140A
24V
+
+
-
0V TO 25V
-
250 F
250 F
2-138
Both regulators, Figures 24 and 25, provide better than 0.02%
load regulation. Because there is constant loop gain at all volt-
age settings, the regulation also remains constant. Line regu-
lation is 0.1% per volt. Hum and noise voltage is less than
200 V as read with a meter having a 10MHz bandwidth.
Figure 28 (a) shows the turn ON and turn OFF characteris-
tics of both regulators. The slow turn on rise is due to the
slow rate of rise of the reference voltage. Figure 26 (B)
shows the transient response of the regulator with the
switching of a 20 load at 20V output.
Tone Control Circuits
High slew rate, wide bandwidth, high output voltage capabil-
ity and high input impedance are all characteristics required
of tone control amplifiers. Two tone control circuits that
exploit these characteristics of the CA3140 are shown in Fig-
ures 27 and 28.
FIGURE 26. WAVEFORMS OF DYNAMIC CHARACTERISTICS
Bottom Trace: Collector of load switching transistor, load = 1A
(A) SUPPLY TURN-ON AND TURNOFF CHARACTERISTICS
Top Trace: Output voltage
OF POWER SUPPLY CURRENTS SHOWN IN FIG-
URES 24 AND 25
200mV/Div and 5 s/Div
5V/Div and 5 s/Div
(B) TRANSIENT RESPONSE
5V/Div and -1s/Div