REFERENCE
368
All prices shown are RRP inc. GST.
Data
Voltage Regulators
Semiconductor Package Pinouts (Bottom View)
Regulators provide a power source which remains very close to a fixed
value, independent of the load placed on it, provided that the current
drawn doesn't exceed the rating of the device. Note: The minimum and
maximum output voltage specs for fixed voltage regulators indicate the
values which can be expected with variations in load on the device. The
same specifications for adjustable regulators indicate the range of voltage output which can be achieved through external componentry.
B2
E
B1
C
B
E
B
E
C
TO-92
TO-92b
TO-92d
K
G
A
S
G
D
E
B
C
E
TO-92
SCR
E
B
TO-92
FET
TO-202
TRIAC
TO-220a
SCR
TO-202
SCR
B
C
SOT-37
a
k
DIODE
B
E
B
TO-3
a
C
TO-5
TO-220
E
k
TO-92j
E
K
A
G
K
A
G
2N6027
TO-92h
C
B
C
E
C
KGA
TO-92g
TO-18
Mt1
Mt2
G
Basic 1A regulated circuit with fixed regulator
The 78xx series of voltage regulators require the input pin to be at least 2.5 volts above the output
voltage. When a bridge rectifier is used, the DC voltage before the regulator is going to be 1.414 x
the AC secondary voltage of the transformer. For good regulation ensure that there is at least 3
volts on the input pin over and above the output voltage of the regulator. Note the maximum input
voltage to the regulator should not exceed 35V.
K
B
TO-66
Suggested 5V Supply Schematic
E
B
C
A
TO-220
TRIAC
TO-220
FET
B
C
E
G
D
S
G (B)
S (C)
D (E)
TO-126
B
C
E
SOT-93
1
8
2
7
3
6
4
5
IC Pinouts
(Top view)
Out
In
Com.
79Lxx
78Lxx
S
E
C
B
TO-247
FET
TOP-66
In
Com.
Out
D
G
TO-3
FET
G
D
S
Mt1
Mt2
G
TO3-P
C
C B E
E Line
All packages are viewed from below or the rear of the
package, with the heatsinking surface upwards, unless
otherwise noted.
LED
8
Vcc (+ve)
7
Output
Input -
3
6
Bal/Strobe
Vee (-ve)
4
5
Balance
+
-
LM311
Comparator
1
14
Output 4
Input1 -
2
13
Input 4 -
Input 1 +
3
12
Input 4 +
Vcc (+ve)
4
11
Vee (-ve)
Input 2 +
5
Output 2
7
10
+
6
Vcc (+ve)
7
Output 2
Offset Null
1
Input 1 +
3
6
Input 2 -
Input -
2
Input 2 +
Input +
3
Vee (-ve)
4
Vee (-ve)
4
5
LM833,TL062,
TL072, TL082
LF353
Dual Op Amps
Input 3 +
9
Input 3 -
8
Output 3
GND
Offset Null
1
Input -
2
Trigger
2
7
Discharge
Input +
3
Output
3
6
Threshold
Vee (-ve)
4
Reset
4
5
Control Voltage
Vcc (+ve)
6
+
Output
5
Offset Null
8
Offset Null
7
Vcc (+ve)
6
Output
5
Freq. Comp.
+
NE5534N
Low Noise
Op Amp
NE555
Timer
TL064,TL074,
TL084, LM324
Quad Op Amps
NC
7
LM741,TL071,
TL081, LF351
Op Amps
Vcc (+ve)
8
1
8
-
Bypass
1
14
Vs
Output 2
1
14
Output 3
Input +
2
13
NC
Output 1
2
13
Output 4
GND
3
12
GND
Vcc
3
12
GND
GND
4
11
GND
Input 1 -
4
11
Input 4 +
GND
10
Input 4 -
9
Input 3 +
8
Input 3 -
5
10
Input 1 +
5
6
9
NC
Input 2 -
6
GND
7
8
Output
Input 2 +
7
LM384 5 Watt
Audio Amp
Current boosted regulator using LM317T or LM350T
This circuit provides a high current capacity variable power supply, delivering 1.2 to 37V at up to
4A. Note the addition of the bypass transistor. Once again the maximum input voltage to the regulator should not exceed 40V.
+
GND
Input -
+
+
-
+
+
Basic voltage regulator using LM317T or LM350T
When a variable power supply is required, this circuit is an ideal solution. The diodes are not essential but are recommended to give short circuit protection. The maximum input voltage to the
regulator should not exceed 40V.
8
2
+
Input 2 -
1
Input 1 -
+
Output 1
Output 1
+
-
2
+
-
1
+
Boosting current output of voltage regulator
When more than one amp of current is required there are a number of options available. One
way is to put in a more expensive higher current regulator and the other is to boost the one amp
device with a bypass transistor. The following circuit shows the necessary configuration to boost
the output to 4A.
GND
Input +
LM339
Quad Comparator
Logic Gates
OR Gate: Output is a logic "0" only if both inputs are "0". A logic "1" at
either or both inputs produces a logic "1" output.
Out
In
Com.
Out
78Lxx
Adj.
Out
In
Com.
79Lxx
Tab
AND Gate: Output is a logic "1" only if both inputs are "1". A logic "0"
at either or both inputs produces a logic "0" output.
In
Pinouts for the LM 317K,
LM 350K and LM 338K
NOR Gate: Output is a logic "1" only if both inputs are "0". A logic
"1" at either or both inputs produces a logic "0" output.
Bottom Views
1 2 3
Top View
Package
78xx
79xx
LM317T
LM350T
LM337
LM2940CT
Tab
Common
Input
Output
Output
Input
Common
Pin 1
Input
Common
Adjust
Adjust
Adjust
Input
Pin 2
Common
Input
Output
Output
Input
Common
Pin 3
Output
Output
Input
Input
Output
Output
NAND Gate: Output is a logic "0" only if both inputs are "1". A logic
"0" at either or both inputs produces a logic "1" output.
Inverter or NOT gate: Output is a logic "1" when input is "0". Output
is a logic "0" when input is "1". ie Inverts the input state.
D Flip-Flop: Transfers the input at D to the output at Q (and its inverse to Q-bar), on the rising edge of the clock signal at C. No change
in any outputs on the falling edge of the clock pulse.
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