CYStech Electronics Corp.
Three Terminal Adjustable Output
Positive Voltage Regulators
Spec. No. : C513E3
Issued Date : 2003.04.09
Revised Date :2005.05.17
Page No. : 1/10
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 ex-
ternal 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 regu-
lator, 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
TO-220AB
Standard Application
Vin
PL317
LM317
+
Vout
R1
+
＊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.
I
Adj
R2
Cin
Cout
0.1µF
1.0µF
V
out=
1.25(
1+
R
2/
R
1
)+I
Adj
R
2
Since
I
Adj
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
T
A
=25℃
Thermal Resistance, Junction-to-Ambient
Thermal Resistance, Junction-to-Case
Operating Junction Temperature Range
Storage Temperature Range
LM317E3
Symbol
V
I
-V
O
P
D
θ
JA
θ
JC
T
J
Tstg
Value
40
Internally Limited
65
5.0
-40 to +125
-65 to +150
Unit
V
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
(V
I
-V
O
=5V,I
O
=0.5A,T
J
=0 to 125℃, unless otherwise noted
)
Characteristics
Line Regulation(
Note 1
)
Load Regulation(
Note 1
)
Symbol Conditions
Reg
line
T
A
=25℃,3.0V≤V
I
-V
O
≤40V
Reg
load
T
A
=25℃,10mA≤I
O
≤1.5A
V
O
≤5.0V
V
O
≥5.0V
Thermal Regulation(
Note 4
) Reg
therm
T
A
=25℃, 20ms pulse
Adjust Pin Current
I
Adj
2.5V≤V
I
-V
O
≤40V,10mA≤I
L
≤1.5A
Adjust Pin Current Change
∆I
Adj
P
D
≤20W
3.0V≤V
I
-V
O
≤40V,10mA≤I
O
≤1.5A
Reference Voltage
Vref
P
D
≤20W
Temperature Stability
Ts
0
≤T
J
≤125℃
Minimum Load Current to I
Lmin
V
I
-V
O
=40V
maintain Regulation
Maximum Output Current Imax
V
I
-V
O
≤15V,P
D
≤20W
V
I
-V
O
≤40V,P
D
≤20W,T
A
=25℃
% of V
O
,T
A
=25℃,10Hz≤f≤10kHz
RMS Noise
N
Ripple Rejection(
Note 2
)
RR
V
O
=10V,f=120Hz
Without C
Adj
C
Adj
=10µF
Long-Term Stability(
Note 3)
S
T
J
=125℃,T
A
=25℃ for endpoint
measurements
Min
-
-
-
-
-
-
1.2
-
-
1. 5
0.15
-
-
66
-
Typ
0.01
5.0
0.1
0.03
50
0.2
1.25
0.7
3.5
2.2
0.4
0.003
65
80
0.3
Max
0.04
25
0.5
0.07
100
5.0
1.3
-
10
-
-
-
-
-
1.0
Unit
%/V
mV
%V
O
%V
O
/W
µA
µA
V
%V
O
mA
A
%V
O
dB
%/1.0k
Hrs
Notes:
1.Load and line regulation are specified at constant junction temperature. Changes in V
O
due to heating effects must be
taken into account separately. Pulse testing with low duty cycle is used.
2.C
Adj
, 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
CYStech Electronics Corp.
Characteristic Curves
Reference Voltage vs Temperature
Spec. No. : C513E3
Issued Date : 2003.04.09
Revised Date :2005.05.17
Page No. : 3/10
Adjustment Current vs Temperature
1.26
1.255
1.25
1.245
1.24
1.235
-50
-25
0
25
50
75
100
125
Adjustment Current---Iadj(μA)
60
55
50
45
40
35
-50
-25
0
25
50
75
100
125
Reference Voltage---Vref(V)
Temperature(℃)
Temperature(℃)
Dropout Voltage vs Input-Output Voltage
Difference
Input-Output Voltage Difference(V)
3
△
Vo=100mA
2.5
2
1.5
1
0
25
50
75
100
125
Temperature(℃)
LM317E3
CYStek Product Specification
CYStech Electronics Corp.
Representative Schematic Diagram
Spec. No. : C513E3
Issued Date : 2003.04.09
Revised Date :2005.05.17
Page No. : 4/10
Vin
Vout
Adjust
∣V
OH
-V
OL
∣
Line Regulation(%/V)=
Vcc
VIH
VIL
Vin
PL317
LM317
Vout
×100
∣V
OL
∣
VOH
VOL
Pulse testing required
1% Duty Cycle is
suggested
Cin
0.1µF
Adjust
IAdj
R1
1%
Co
+
1µF
RL
R2
1%
Fig 1. Line Regulation and
∆I
Adj
/Line test circuit
LM317E3
CYStek Product Specification
CYStech Electronics Corp.
Vin
VI
PL317
LM317
Adjust
IAdj
Cin
0.1µF
R2
1%
R1
1%
Co
+
Spec. No. : C513E3
Issued Date : 2003.04.09
Revised Date :2005.05.17
Page No. : 5/10
Vout
IL
*
1µF
RL
(max load)
Vo(min load)
Vo(max load)
RL
(min load)
*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)=
Vo(min load)
×100
Fig 2. Load Regulation and
∆I
Adj
/Load test circuit
Vin
LM317
PL317
Vout
IL
R1
1%
Adjust
IAdj
Cin
VI
ISET
0.1µF
Vref
+
1µF
Co
RL
Vo
R2
1%
＊
Pulse testing required.
1% Duty Cycle is suggested.
To calculate R2: Vout=I
SET
R2+1.250V
Assume I
SET
=5.25mA
Fig 3. Standard Test Circuit
LM317E3
CYStek Product Specification
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