LM317L LINEAR INTEGRATED CIRCUIT
LOW CURRENT 1.25V TO 37V
ADJUSTABLE VOLTAGE
REGULATOR
DESCRIPTION
The Contek LM317L is a monolithic integrated
circuit, designed for use as positive adjustable voltage
regulator. It is designed to supply until 100mA of load
current with an output voltage adjustable over a 1.25V
to 37V range.
FEATURES
*Output voltage range: 1.25V to 37V
*Output current in excess of 100mA
*Line regulation typ. 0.01%
*Load regulation typ. 0.1%
*Thermal overload protection
*Short circuit protection
*Output transistor safe area compensation
*Floating operation for high voltage applications
PIN CONFIGURATIONS
3
21
ADJUST
TO-92 Plastic Package
Bottom View
OUT
IN
VIN
VOUT
V
ADJ
OUT
1
2
Contek
LM317L
3
4
SOP-8 PACKAGE
SOP-8
1
TO-92
8
NC
VOUT
7
VOUT
6
5
NC
ABSOLUTE MAXIMUM RATING
PARAMETER SYMBOL VALUE UNIT
Input-Output Differential Voltage Vi-Vo 40 V
Power Dissipation Pd Internally Limited
Operating Junction Temperature Range Topr 0~125 C
Storage Temperature Range Tstr -55 ~ 150 C
Contek Microelectronics Co.,Ltd.
CONTEK
http://www.contek-ic.com E-mail:sales@contek-ic.com
1
LM317L LINEAR INTEGRATED CIRCUIT
SCHEMATIC DIAGRAM
INPUT
R16
Q22
D2
R19
Q25
R17
R21
C3
R20
R18
R22
Q26
R23
D3
R24
R25
R26
OUTPUT
ADJUST
Q1
D1
Contek
R1 R2 R3 R4 R5
Q10
Q2
R6 Q4
Q3
Q8
R8
R7
Q9
Q6
Q12
Q11
Q7
Q5
R11R12
R10
R9
Q13
R13
Q15
Q14
C1
Q18
Q16
Q17
C2
Q20
Q19
Q21
R15
R14
TEST CIRCUIT
CONTEK
Vi Vo
Contek
32
LM317L
R1
Cout
Cin
1
Vref
0.1mF
1mF
Iadj
R2
Contek Microelectronics Co.,Ltd.
http://www.contek-ic.com E-mail:sales@contek-ic.com
2
LM317L LINEAR INTEGRATED CIRCUIT
ELECTRICAL CHARACTERISTICS(Vi-Vo=5V, Io=40mA, 0<=Tj<=125 C, unless otherwise specified)
PARAMETER SYMBOL TEST CONDITIONS MIN TYP MAX UNIT
Line Regulation DVo Vi-Vo=3~40V
L<20mA
I
Load Regulation DVo Vo<=5V
Io=5~100mA
Vo>=5V
Io=5~100mA
Adjustment Pin Current IADJ 50 100 mA
Adjustment Pin Current DIADJ Vi-Vo=3~40V
Reference Voltage VREF Vi-Vo=3~40V
Output Voltage Temperature Stability DVo/ Vo 0.7 %
Minimum Load Current Io(min) Vi-Vo=40V 3.5 5 mA
Maximum Output Current Io(max) Vi-Vo=3~13V
Output Noise Voltage
(Percentance of Vo)
Supply Voltage Rejection(*) SVR Tj=25 C
(*) CADJ is connected between Adjust pin and Ground.
eN B=10Hz~10KHz
Io=5~100mA, Pd< 625 mW
Io=5~100 mA , Pd< 625 mW
Vi-Vo=40V
f=120Hz
Tj=25 C
0.01 0.04 %/V
0.02 0.07 %/V
Tj=25 C 5 25 mV
20 70 mV
Tj=25 C 0.1 0.5 %
0.3 1.5 %
0.2 5 mA
1.2 1.25 1.3 V
100 200
50
Tj=25 C
CADJ=0 65 dB
CADJ=10mF6680 dB
0.003 %
mA
0
I
(mA)
300
200
100
0 102030VIN-VOUT(V)
CONTEK
CURRENT LIMIT
Tj=25 C
MINIMUM OPERATING CURRENT
I0
(mA)
Tj=25 C
3.0
2.5
2.0
1.5
1.0
0.5
0 102030VIN-VOUT(V)
Contek Microelectronics Co.,Ltd.
http://www.contek-ic.com E-mail:sales@contek-ic.com
3
LM317L LINEAR INTEGRATED CIRCUIT
APPLICATION INFORMATION
The Contek LM317L provides an internal reference voltage of 1.25V between the output and adjustments terminals.
This is used to set a constant current flow across an external resistor divider, giving an output voltage VO of:
VO=V
REF (1+R2/R1) + IADJ R2
The device is designed to minimize the term I
changes. Usually, the error term IADJ. R2 can be neglected. To obtain the previous requirement, all the regulator
quiescent current is returned to the output terminal, imposing a minimum load current condition. If the load is
insufficient, the output voltage will rise. The Contek LM317L is a floating regulator, input-output differential voltage ,
supplies of very high voltage with respect to ground can be regulated as long as the maximum input-output differential
is not exceeded. Furthermore, programmable regulators are easily obtainable and, by connecting a fixed resistor
between the adjustment and output, the device can be used as a precision current regulator.
Vi Vo
ADJ (100mA max) and to maintain it very constant with line and load
BASIC ADJUSTABLE REGULATOR
Contek
32
LM317L
1
Vref
Iadj
R1
I1
R2
CONTEK
Contek Microelectronics Co.,Ltd.
http://www.contek-ic.com E-mail:sales@contek-ic.com
4
LM317L LINEAR INTEGRATED CIRCUIT
VOLTAGE REGULATOR WITH PROTECTION DIODES
1N4001
D1
Vi
Contek
32
LM317L
ADJ
1
C1
0.1mF
5K W
R2
SLOW TURN-ON 15V REGULATOR
Vi
3
C2
0.1 mF
2.7K W
Contek
LM317L
1
R2
2
2N2907
R1
240
W
R3
50K W
Vo=15V
D1
1N4001
C1
25mF
5V ELECTRONIC SHUT-DOWN REGULATOR
Vi
7V to
35V
3
C1
0.1 mF
Contek
LM317L
1
2
R1
240 W
C2
0.1 mF
1N4001
Vo=5V
Vo
240
W
D2
R1
C3
C2
10mF
1mF
CURRENT REGULATOR
Vi
Io=
Contek
32
LM317L
1
Vref
R1
+ IADJ@
1.25V
R1
Vo
DIGITALLY SELECTED OUTPUTS
Vi 3 2
Contek
LM317L
1
R1
IADJ
Io
Vo
R1
240 W
CONTEK
R2
720W
2N2219
TTL
INPUT
R2
DIGITAL INPUTS(R2 sets maximun Vo)
Contek Microelectronics Co.,Ltd.
http://www.contek-ic.com E-mail:sales@contek-ic.com
5
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