LM317L LINEAR INTEGRATED CIRCUIT
1
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
TO-92
1
SOP-8
PIN CONFIGURATIONS
1
2
3
4
8
7
6
5
NC
VOUT
VOUT
VIN
Contek
LM317L
ADJ
VOUT
VOUT
NC
3
ADJUST
OUT
IN
21
TO-92 Plastic Package
Bottom View SOP-8 PACKAGE
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
Contek Microelectronics Co.,Ltd.
http://www.contek-ic.com E-mail:sales@contek-ic.com
LM317L LINEAR INTEGRATED CIRCUIT
2
SCHEMATIC DIAGRAM
TEST CIRCUIT
R1 R2 R3 R4 R5
R6 Q4
Q3 Q5
Q8
R7
Q6
R8
Q9
Q7
R9
R10R11R12
Q11Q12
R13
Q13
Q14
Q15
Q17
Q16
R15
Q10
Q19
Q18
Q20
Q21
R16
C3
R20
R21
R17
R19
R18
Q25
R25
Q26
R26
D2
R23
D3
R24
OUTPUT
R14
R22
INPUT
Q1
D1
Q2
ADJUST
Q22
C1
C2
Contek
LM317L
Vi Vo
32
1Vref R1
R2
Iadj
Cin
0.1mF
Cout
1mF
Contek
CONTEK
Contek Microelectronics Co.,Ltd.
http://www.contek-ic.com E-mail:sales@contek-ic.com
LM317L LINEAR INTEGRATED CIRCUIT
3
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
IL<20mA
Tj=25 C 0.01 0.04 %/V
0.02 0.07 %/V
Load Regulation DVo Vo<=5V
Io=5~100mA
Tj=25 C 5 25 mV
20 70 mV
Vo>=5V
Io=5~100mA
Tj=25 C 0.1 0.5 %
0.3 1.5 %
Adjustment Pin Current IADJ 50 100 mA
Adjustment Pin Current DIADJ Vi-Vo=3~40V
Io=5~100mA, Pd< 625 mW
0.2 5 mA
Reference Voltage VREF Vi-Vo=3~40V
Io=5~100 mA , Pd< 625 mW
1.2 1.25 1.3 V
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
Vi-Vo=40V
100 200
50
mA
Output Noise Voltage
(Percentance of Vo)
eN B=10Hz~10KHz
Tj=25 C
0.003 %
Supply Voltage Rejection(*) SVR Tj=25 C
f=120Hz
CADJ=0 65 dB
CADJ=10mF6680 dB
(*) CADJ is connected between Adjust pin and Ground.
100
200
300
I0
(mA)
0 102030VIN-VOUT(V)
Tj=25 C
CURRENT LIMIT I0
(mA)
0 102030VIN-VOUT(V)
Tj=25 C
MINIMUM OPERATING CURRENT
0.5
1.0
1.5
2.0
2.5
3.0
CONTEK
Contek Microelectronics Co.,Ltd.
http://www.contek-ic.com E-mail:sales@contek-ic.com
LM317L LINEAR INTEGRATED CIRCUIT
4
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=VREF (1+R2/R1) + IADJ R2
The device is designed to minimize the term IADJ (100mA max) and to maintain it very constant with line and load
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.
Contek
LM317L
Vi Vo
32
1
Vref
R1
R2
Iadj
I1
BASIC ADJUSTABLE REGULATOR
CONTEK
Contek Microelectronics Co.,Ltd.
http://www.contek-ic.com E-mail:sales@contek-ic.com
LM317L LINEAR INTEGRATED CIRCUIT
5
Io= Vref
R1 + IADJ @
1.25V
R1
Contek
LM317L
Vi 3 2
1R1
240 W
DIGITAL INPUTS(R2 sets maximun Vo)
Vo
R2
DIGITALLY SELECTED OUTPUTS
Contek
LM317L
Vi
Vo
32
1
R1 Io
IADJ
CURRENT REGULATOR
Contek
LM317L
Vi
0.1 mF
25mF
Vo=15V
32
1
R3
R2
R1
C1
C2
2.7K W
240 W
2N2907
50K W
D1
1N4001
SLOW TURN-ON 15V REGULATOR
Contek
LM317L
Vi
0.1 mF
Vo=5V
32
1
R2
R1
TTL
INPUT
C1
720W
240 W
7V to
35V
0.1 mF
C2
2N2219
5V ELECTRONIC SHUT-DOWN REGULATOR
Contek
LM317L
Vi
0.1mF
1mF
Vo
32
1R1
R2
ADJ
D1
1N4001
1N4001
D2
C3
C1
5K W
10mF
C2
240 W
VOLTAGE REGULATOR WITH PROTECTION DIODES
CONTEK
Contek Microelectronics Co.,Ltd.
http://www.contek-ic.com E-mail:sales@contek-ic.com
