LM317L3

CYStech Electronics Corp.
Spec. No. : C513L3
Issued Date : 2003.04.09
Revised Date :2013.10.31
Page No. : 1/12
Three Terminal Adjustable Output
Positive Voltage Regulators
LM317L3
The LM317L3 is an adjustable 3–terminal positive voltage regulator capable of supplying in excess of
1.5A over an output voltage range of 1.2 V to 37 V. This voltage regulator is exceptionally easy to use and
requires only two external resistors to set the output voltage. Further, it employs internal current limiting,
thermal shutdown and safe area compensation, making it essentially blow–out proof.
The LM317L3 serves a wide variety of applications including local, on-card regulation. This device can
also be used to make a programmable output regulator, or by connecting a fixed resistor between the
adjustment and output, the LM317L3 can be used as a precision current regulator.
● Output Current in Excess of 1.5 A
● Output Adjustable between 1.2 V and 37 V
● Internal Thermal Overload Protection
● Internal Short Circuit Current Limiting Constant with Temperature
● Output Transistor Safe–Area Compensation
● Floating Operation for High Voltage Applications
● Eliminates Stocking many Fixed Voltages
● Pb-free lead plating and halogen-free package.
Standard Application
Vin
Vout
LM317
PL317
+
Cin
R1
IAdj
0.1μF
＊Cin is required if regulator is located an appreciate
distance from power supply filter.
＊＊Cout is not needed for stability, however, it does
improve transient response.
+
R2
Cout
1.0μF
Vout=1.25(1+R2/R1)+IAdjR2
Since IAdj is controlled to less than 100 μA, the
error associated with this term is negligible in
most applications.
Ordering Information
Device
LM317L3-0-T3-G
Package
SOT-223
(Pb-free lead plating and halogen-free package)
Shipping
2500 pcs / tape & reel
Environment friendly grade : S for RoHS compliant products, G for RoHS compliant and
green compound products
Packing spec, T3 : 2500 pcs / tape & reel, 13” reel
Product rank, zero for no rank products
Product name
LM317L3
CYStek Product Specification
Spec. No. : C513L3
Issued Date : 2003.04.09
Revised Date :2013.10.31
Page No. : 2/12
CYStech Electronics Corp.
Package Information
1
2
3
Pin
1
2
3
Function
ADJ
OUTPUT
INPUT
SOT-223
Maximum Ratings TA=25°C
Rating
Input-Output Voltage Differential
Power Dissipation
Operating Junction Temperature Range
Storage Temperature Range
Symbol
VI-VO
PD
TJ
Tstg
Value
40
1.5
-40 to +125
-65 to +150
Unit
V
W
℃
℃
Electrical Characteristics(VI-VO=5V,IO=0.5A,TJ=0 to 125℃, unless otherwise noted)
Characteristics
Line Regulation(Note 1)
Load Regulation(Note 1)
Symbol Conditions
Reg line TA=25℃,3.0V≤VI-VO≤40V
Reg load TA=25℃,10mA≤IO≤1.5A
VO≤5.0V
VO≥5.0V
Thermal Regulation(Note 4) Reg therm TA=25℃, 20ms pulse
Adjust Pin Current
IAdj
2.5V≤VI-VO≤40V,10mA≤IL≤1.5A
Adjust Pin Current Change ΔIAdj
PD≤5W
3.0V≤VI-VO≤40V,10mA≤IO≤1.5A
Reference Voltage
Vref
PD≤5W
Temperature Stability
Ts
0≤TJ≤125℃
Minimum Load Current to ILmin
VI-VO=40V
maintain Regulation
Maximum Output Current Imax
VI-VO≤15V,PD≤5W
VI-VO≤40V,PD≤5W,TA=25℃
% of VO,TA=25℃,10Hz≤f≤10kHz
RMS Noise
N
Ripple Rejection(Note 2)
RR
VO=10V,f=120Hz
Without CAdj
CAdj=10μF
Long-Term Stability(Note 3) S
TJ=125℃,TA=25℃ for endpoint
measurements
Min
-
Typ
0.01
Max
0.04
Unit
%/V
-
5.0
0.1
0.03
50
0.2
25
0.5
0.07
100
5.0
mV
%VO
%VO/W
μA
μA
1.2
1.25
1.3
V
-
0.7
3.5
10
%VO
mA
1. 5
0.15
-
2.2
0.4
0.003
-
A
66
-
65
80
0.3
1.0
%VO
dB
%/1.0k
Hrs
Notes:1.Load and line regulation are specified at constant junction temperature. Changes in VO due to heating effects must be
taken into account separately. Pulse testing with low duty cycle is used.
2.CAdj, when used, is connected between the adjustment pin and ground.
LM317L3
CYStek Product Specification
CYStech Electronics Corp.
Spec. No. : C513L3
Issued Date : 2003.04.09
Revised Date :2013.10.31
Page No. : 3/12
3.Since long-term stability cannot be measured on each device before shipment, this specification is an engineering
estimate of average stability from lot to lot.
4.Power dissipation within an IC voltage regulator produces a temperature gradient on the die, affecting individual IC
components on the die. These effects can be minimized by proper integrated circuit design and layout techniques.
Thermal regulation is the effect of these temperature gradients on the output voltage and is expressed in percentage
of output change per watt of power change in a specified time.
Typical Characteristics
Reference Voltage vs Temperature
Adjustment Current vs Temperature
60
Adjustment Current---Iadj(μA)
Reference Voltage---Vref(V)
1.26
1.255
1.25
1.245
1.24
1.235
55
50
45
40
35
-50
-25
0
25
50
75
100
125
-50
-25
0
25
50
75
100
125
Temperature(℃)
Temperature(℃)
Input-Output Voltage Difference(V)
Dropout Voltage vs Input-Output Voltage
Difference
3
2.5
2
1.5
1
0
25
50
75
100
125
Temperature(℃)
LM317L3
CYStek Product Specification
CYStech Electronics Corp.
Spec. No. : C513L3
Issued Date : 2003.04.09
Revised Date :2013.10.31
Page No. : 4/12
Representative Schematic Diagram
Vin
Vout
Adjust
∣VOH-VOL∣
Line Regulation(%/V)=
×100
∣VOL∣
Pulse testing required
1% Duty Cycle is
suggested
Fig 1. Line Regulation and ΔIAdj/Line test circuit
LM317L3
CYStek Product Specification
CYStech Electronics Corp.
Spec. No. : C513L3
Issued Date : 2003.04.09
Revised Date :2013.10.31
Page No. : 5/12
Vo(min load)-Vo(max load)
Load Regulation(mV)=Vo(min load)-Vo(max load)
Load Regulation(%Vo)=
×100
Vo(min load)
Fig 2. Load Regulation and ∆IAdj/Load test circuit
＊ Pulse testing required.
1% Duty Cycle is suggested.
To calculate R2: Vout=ISETR2+1.250V
Assume ISET=5.25mA
Fig 3. Standard Test Circuit
LM317L3
CYStek Product Specification
CYStech Electronics Corp.
Spec. No. : C513L3
Issued Date : 2003.04.09
Revised Date :2013.10.31
Page No. : 6/12
Fig 4. Ripple Rejection Test Circuit
Application Information
Basic Circuit Operation
The LM317 is a 3-terminal floating regulator. In operation, the LM317 develops and maintains a nominal
1.25V reference (Vref) between its output and adjustment terminals. This reference voltage is converted
to a programming current (Iprog) by R1(see Fig 5), and this constant current flows through R2 to ground.
The regulated output voltage is given by:
Vout=Vref(1+R2/R1)+IAdjR2
Since the current from the adjustment terminal (IAdj) represents an error term in the equation, the LM317
was designed to control IAdj to less than 100 μA and keep it constant. To do this, all quiescent operating
current is returned to the output terminal. This imposes the requirement for a minimum load current. If
the load current is less than this minimum, the output voltage will rise.
Since the LM317 is a floating regulator, it is only the voltage differential across the circuit which is
important to performance, and operation at high voltages with respect to ground is possible.
Fig 5. Basic Circuit Configuration
LM317L3
CYStek Product Specification
CYStech Electronics Corp.
Spec. No. : C513L3
Issued Date : 2003.04.09
Revised Date :2013.10.31
Page No. : 7/12
Load Regulation
The LM317 is capable of providing extremely good load regulation, but a few precautions are needed to
obtain maximum performance. For best performance, the programming resistor (R1) should be connected
as close to the regulator as possible to minimize line drops which effectively appear in series with the
reference, thereby degrading regulation. The ground end of R2 can be returned near the load ground to
provide remote ground sensing and improve load regulation.
External Capacitors
A 0.1μF disc or 1.0μF tantalum input bypass capacitor (Cin) is recommended to reduce the sensitivity to
input line impedance.
The adjustment terminal may be bypassed to ground to improve ripple rejection. This capacitor (CAdj)
prevents ripple from being amplified as the output voltage is increased. A 10μF capacitor should improve
ripple rejection about 15 dB at 120 Hz in a 10V application.
Although the LM317 is stable with no output capacitance, like any feedback circuit, certain values of
external capacitance can cause excessive ringing. An output capacitance (Co) in the form of a 1.0μF
tantalum or 25μF aluminum electrolytic capacitor on the output swamps this effect and insures stability.
Protection Diodes
When external capacitors are used with any IC regulator, it is sometimes necessary to add protection
diodes to prevent the capacitors from discharging through low current points into the regulator.
Fig 6 shows the LM317 with the recommended protection diodes for output voltages in excess of 25V or
high capacitance values (Co>25μF,CAdj>10μF). Diode D1 prevents Co from discharging thru the IC
during an input short circuit. Diode D2 protects against capacitor CAdj discharging through the IC during
an output short circuit. The combination of diodes D1 and D2 prevents CAdj from discharging through the
IC during an input short circuit.
Fig 6. Voltage Regulator with Protection Diodes
LM317L3
CYStek Product Specification
CYStech Electronics Corp.
Spec. No. : C513L3
Issued Date : 2003.04.09
Revised Date :2013.10.31
Page No. : 8/12
Application Circuits
Fig 7. “Laboratory” Power Supply with Adjustable Current Limit and Output Voltage
R1=Vref/(Iomax+IDSS) R2≤Vref/IDSS
Vo<BVDSS+1.25V+Vss
ILmin-IDSS<Io<1.5A
As shown 0<Io<1.0A
Fig 8. Adjustable Current Limiter
LM317L3
Fig 9. 5.0V Electronic Shutdown Regulator
CYStek Product Specification
CYStech Electronics Corp.
Fig 10. Slow Turn-on Regulator
Spec. No. : C513L3
Issued Date : 2003.04.09
Revised Date :2013.10.31
Page No. : 9/12
Fig 11. Current Regulator
Recommended soldering footprint
LM317L3
CYStek Product Specification
CYStech Electronics Corp.
Spec. No. : C513L3
Issued Date : 2003.04.09
Revised Date :2013.10.31
Page No. : 10/12
Reel Dimension
Carrier Tape Dimension
LM317L3
CYStek Product Specification
CYStech Electronics Corp.
Spec. No. : C513L3
Issued Date : 2003.04.09
Revised Date :2013.10.31
Page No. : 11/12
Recommended wave soldering condition
Product
Pb-free devices
Peak Temperature
260 +0/-5 °C
Soldering Time
5 +1/-1 seconds
Recommended temperature profile for IR reflow
Profile feature
Average ramp-up rate
(Tsmax to Tp)
Preheat
−Temperature Min(TS min)
−Temperature Max(TS max)
−Time(ts min to ts max)
Time maintained above:
−Temperature (TL)
− Time (tL)
Peak Temperature(TP)
Time within 5°C of actual peak
temperature(tp)
Ramp down rate
Time 25 °C to peak temperature
Sn-Pb eutectic Assembly
Pb-free Assembly
3°C/second max.
3°C/second max.
100°C
150°C
60-120 seconds
150°C
200°C
60-180 seconds
183°C
60-150 seconds
240 +0/-5 °C
217°C
60-150 seconds
260 +0/-5 °C
10-30 seconds
20-40 seconds
6°C/second max.
6 minutes max.
6°C/second max.
8 minutes max.
Note : All temperatures refer to topside of the package, measured on the package body surface.
LM317L3
CYStek Product Specification
Spec. No. : C513L3
Issued Date : 2003.04.09
Revised Date :2013.10.31
Page No. : 12/12
CYStech Electronics Corp.
SOT-223 Dimension
A
Marking:
LM317
B
C
1
2
Date Code
□□□□
3
D
E
Style: Pin 1.Adj 2.Output 3.Input
F
H
G
a1
I
a2
3-Lead SOT-223 Plastic
Surface Mounted Package
CYStek Package Code: L3
*: Typical
Inches
Min.
Max.
0.1142
0.1220
0.2638
0.2874
0.1299
0.1457
0.0236
0.0315
*0.0906
0.2480
0.2638
DIM
A
B
C
D
E
F
Millimeters
Min.
Max.
2.90
3.10
6.70
7.30
3.30
3.70
0.60
0.80
*2.30
6.30
6.70
DIM
G
H
I
a1
a2
Inches
Min.
Max.
0.0551
0.0709
0.0098
0.0138
0.0008
0.0039
*13o
0o
10 o
Millimeters
Min.
Max.
1.40
1.80
0.25
0.35
0.02
0.10
*13o
0o
10 o
Notes: 1.Controlling dimension: millimeters.
2.Maximum lead thickness includes lead finish thickness, and minimum lead thickness is the minimum thickness of base material.
3.If there is any question with packing specification or packing method, please contact your local CYStek sales office.
Material:
• Lead: Pure tin plated.
• Mold Compound: Epoxy resin family, flammability solid burning class: UL94V-0.
Important Notice:
• All rights are reserved. Reproduction in whole or in part is prohibited without the prior written approval of CYStek.
• CYStek reserves the right to make changes to its products without notice.
• CYStek semiconductor products are not warranted to be suitable for use in Life-Support Applications, or systems.
• CYStek assumes no liability for any consequence of customer product design, infringement of patents, or application assistance.
LM317L3
CYStek Product Specification