CYSTEKEC LM317E3

CYStech Electronics Corp.
Spec. No. : C513E3
Issued Date : 2003.04.09
Revised Date :2005.05.17
Page No. : 1/10
Three Terminal Adjustable Output
Positive Voltage Regulators
LM317E3
The LM317E3 is an adjustable 3–terminal positive voltage regulator capable
of supplying in excess of 1.5 A 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 LM317E3 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
LM317E3 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
Standard Application
Vin
Cin
0.1µF
Vout
PL317
LM317
+
TO-220AB
＊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.
R1
IAdj
+
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.
Maximum Ratings
Rating
Input-Output Voltage Differential
Power Dissipation
TA=25℃
Thermal Resistance, Junction-to-Ambient
Thermal Resistance, Junction-to-Case
Operating Junction Temperature Range
Storage Temperature Range
LM317E3
Symbol
VI-VO
Value
40
Unit
V
PD
θJA
θJC
TJ
Tstg
Internally Limited
65
5.0
-40 to +125
-65 to +150
W
℃/W
℃/W
℃
℃
CYStek Product Specification
CYStech Electronics Corp.
Spec. No. : C513E3
Issued Date : 2003.04.09
Revised Date :2005.05.17
Page No. : 2/10
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 ∆IAdj
PD≤20W
3.0V≤VI-VO≤40V,10mA≤IO≤1.5A
Reference Voltage
Vref
PD≤20W
Temperature Stability
Ts
0≤TJ≤125℃
Minimum Load Current to ILmin
VI-VO=40V
maintain Regulation
Maximum Output Current Imax
VI-VO≤15V,PD≤20W
VI-VO≤40V,PD≤20W,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.
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.
LM317E3
CYStek Product Specification
Spec. No. : C513E3
Issued Date : 2003.04.09
Revised Date :2005.05.17
Page No. : 3/10
CYStech Electronics Corp.
Characteristic Curves
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
Temperature(℃)
-50
-25
0
25
50
75
100
125
Temperature(℃)
Input-Output Voltage Difference(V)
Dropout Voltage vs Input-Output Voltage
Difference
△Vo=100mA
3
2.5
2
1.5
1
0
25
50
75
100
125
Temperature(℃)
LM317E3
CYStek Product Specification
Spec. No. : C513E3
Issued Date : 2003.04.09
Revised Date :2005.05.17
Page No. : 4/10
CYStech Electronics Corp.
Representative Schematic Diagram
Vin
Vout
Adjust
∣VOH-VOL∣
Line Regulation(%/V)=
×100
∣VOL∣
Vcc
VIH
VOH
VIL
Vin
VOL
Vout
PL317
LM317
Pulse testing required
1% Duty Cycle is
suggested
Cin
Adjust
IAdj
R1
1%
Co
+
1µF
RL
0.1µF
R2
1%
Fig 1. Line Regulation and ∆IAdj/Line test circuit
LM317E3
CYStek Product Specification
Spec. No. : C513E3
Issued Date : 2003.04.09
Revised Date :2005.05.17
Page No. : 5/10
CYStech Electronics Corp.
Vin
Vout
VI
IL
PL317
LM317
Adjust
R1
1%
*
IAdj
Cin
Co
+
Vo(min load)
RL
(max load)
1µF
Vo(max load)
RL
(min load)
0.1µF
R2
1%
*Pulse testing required.
1% Duty Cycle is suggest
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
Vin
Vout
LM317
PL317
Adjust
IL
R1
1%
IAdj
Cin
Vref
+
0.1µF
1µF
Co
RL
Vo
VI
ISET
R2
1%
＊ Pulse testing required.
1% Duty Cycle is suggested.
To calculate R2: Vout=ISETR2+1.250V
Assume ISET=5.25mA
Fig 3. Standard Test Circuit
LM317E3
CYStek Product Specification
Spec. No. : C513E3
Issued Date : 2003.04.09
Revised Date :2005.05.17
Page No. : 6/10
CYStech Electronics Corp.
Vin
24V
Vout
PL317
LM317
14V
f=120Hz
Adjust
R1
1%
D1 *
1N4002
+
Cin
0.1µF
1µF
Co
RL
Vout=10V
Vo
R2
1%
CAdj
+
10µF
* D1 Discharges CAdj if output is shorted to ground
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.
Vin
Vout
Vout
PL317
LM317
Vref
Adjust
R1
Iprog
IAdj
R2
Vref=1.25V typical
LM317E3
Fig 5. Basic Circuit Configuration
CYStek Product Specification
CYStech Electronics Corp.
Spec. No. : C513E3
Issued Date : 2003.04.09
Revised Date :2005.05.17
Page No. : 7/10
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.
D1
Vin
1N4002
Vout
PL317
LM317
Cin
Adjust
D2
1N4002
R1
+
R2
Co
CAdj
Fig 6. Voltage Regulator with Protection Diodes
LM317E3
CYStek Product Specification
Spec. No. : C513E3
Issued Date : 2003.04.09
Revised Date :2005.05.17
Page No. : 8/10
CYStech Electronics Corp.
Application Circuits
D6*
1N4002
Vout
Vin
32V to 40 V
Vin 1
RSC
Vin 2
LM317
PL317
(1)
(1)
Adjust 1
240
Adjust 2
D1
1N4001
0.1µF
Current Limit Adjust
1.0k
Iout Vout
Vout 2
LM317
PL317
(2)
(2)
D5
1N4001
+
Voltage Adjust
5.0k
D2
1N4001
Q1
2N3822
+
10µF
1.0µF
Tantalum
D3
Output Range:0≦Vo≦25V
1N4001
0≦Io≦1.5A
D4
1N4001
-10V
Q2
2N5640
Diodes D1 and D2 and transistor Q2 are added to
allow adjustment of output voltage to 0V.
* D6 protects both LM317's during an input short circuit.
-10V
Fig 7. “Laboratory” Power Supply with Adjustable Current Limit and Output Voltage
+25V
Vin
Vout
PL317
LM317
Adjust
Iout
R1
D1*
1.25
Vin
R2
D1
1N4001
100
*To provide current limiting of Io to the system
groung, the source of the FET must be tied to a
negative voltage below -1.25V.
2N5640
D2
1N4001
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
LM317E3
1N4002
Vout
LM317
PL317
120
+
Adjust
720
1.0µF
MPS2222
1.0k
TTL
Control
*D1 protects the device during an input short circuit.
Vss*
Fig 9. 5.0V Electronic Shutdown Regulator
CYStek Product Specification
Spec. No. : C513E3
Issued Date : 2003.04.09
Revised Date :2005.05.17
Page No. : 9/10
CYStech Electronics Corp.
Vin
Vout
PL317
LM317
Vin
240
Adjust
1N4001
50k
Vout
PL317
LM317
Adjust
MPS2907
R2
+
10µF
Iout
R1
IAdj
Iout=(Vref/R1)+IAdj
=1.25V/R1
10mA≦Iout≦1.5A
Fig 10. Slow Turn-on Regulator
LM317E3
Fig 11. Current Regulator
CYStek Product Specification
CYStech Electronics Corp.
Spec. No. : C513E3
Issued Date : 2003.04.09
Revised Date :2005.05.17
Page No. : 10/10
TO-220AB Dimension
Marking:
A
B
D
E
C
317
H
K
M
I
3
G
N
2
1
4
Style: Pin 1.Adj 2.Vout 3.Vin
4.Vout
O
P
3-Lead TO-220AB Plastic Package
CYStek Package Code: E3
*
: Typical
Inches
Min.
Max.
0.2197 0.2949
0.3299 0.3504
0.1732
0.185
0.0453 0.0547
0.0138 0.0236
0.3803 0.4047
*0.6398
DIM
A
B
C
D
E
G
H
Millimeters
Min.
Max.
5.58
7.49
8.38
8.90
4.40
4.70
1.15
1.39
0.35
0.60
9.66
10.28
*16.25
DIM
I
K
M
N
O
P
Inches
Min.
Max.
*0.1508
0.0295 0.0374
0.0449 0.0551
*0.1000
0.5000 0.5618
0.5701 0.6248
Millimeters
Min.
Max.
*3.83
0.75
0.95
1.14
1.40
*2.54
12.70
14.27
14.48
15.87
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: 42 Alloy ; solder plating
• 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.
LM317E3
CYStek Product Specification