Supertex inc. LR8
Supertex inc. ● 1235 Bordeaux Drive, Sunnyvale, CA 94089 ● Tel: 408-222-8888 ● www.supertex.com
Features
►13.2 - 450V input voltage range
►Adjustable 1.20 - 440V output regulation
►5% output voltage tolerance
►Output current limiting
►10µA typical ADJ current
►Internal junction temperature limiting
Applications
►Off-line SMPS startup circuits
►Adjustable high voltage constant current source
►Industrial controls
►Motor controls
►Battery chargers
►Power supplies
General Description
The Supertex LR8 is a high voltage, low output current, adjustable
linear regulator. It has a wide operating input voltage range of
13.2 - 450V. The output voltage can be adjusted from 1.20 - 440V
provided that the input voltage is at least 12V greater than the
output voltage. The output voltage can be adjusted by means of
two external resistors R1 and R2 as shown in the typical application
circuits. The LR8 regulates the voltage difference between VOUT
and ADJ pins to a nominal value of 1.20V. The 1.20V is amplied
by the external resistor ratio R1 and R2. An internal constant
bias current of typically 10µA is connected to the ADJ pin. This
increases VOUT by a constant voltage of 10µA times R2.
The LR8 has current limiting and temperature limiting. The output
current limit is typically 20mA and the minimum temperature limit
is 125°C. An output short circuit current will therefore be limited
to 20mA. When the junction temperature reaches its temperature
limit, the output current and/or output voltage will decrease to
keep the junction temperature from exceeding its temperature
limit. For SMPS start-up circuit applications, the LR8 turns off
when an external voltage greater than the output voltage of the
LR8 is applied to VOUT of the LR8. To maintain stability, a bypass
capacitor of 1.0µF or larger and a minimum DC output current of
500µA are required.
The device is available in TO-243AA (SOT-89), TO-252 (D-PAK),
and TO-92 packages.
Typical Application Circuit
High Input Voltage,
Adjustable 3-Terminal Linear Regulator
LR8
VIN
*
* Required for conditions where VIN is less than VOUT.
R1
R2
C2
C1
RLOAD
VOUT
VOUT
ADJ
VIN
2
LR8
Supertex inc. ● 1235 Bordeaux Drive, Sunnyvale, CA 94089 ● Tel: 408-222-8888 ● www.supertex.com
Ordering Information
Device
Package Options
TO-252
(D-PAK) TO-92 TO-243AA
(SOT-89)
LR8 LR8K4-G LR8N3-G LR8N8-G
-G indicates package is RoHS compliant (‘Green’)
Absolute Maximum Ratings
Parameter Value
VIN input voltage (voltages ref to ADJ) -0.5V to +480V
Output voltage range -0.5V to +470V
Operating ambient temperature range -40°C to +85°C
Operating junction temperature range -40°C to +125°C
Storage temperature range -65°C to +150°C
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent
damage to the device. These are stress ratings only, and functional operation of the
device at these or any other conditions beyond those indicated in the operational sections
of the specications is not implied. Exposure to absolute maximum rating conditions for
extended periods may affect device reliability.
Electrical Characteristics
(Test conditions unless otherwise specied: -40°C < TA < 85°C.)
Sym Parameter Min Typ Max Units Conditions
VIN - VOUT Input to output voltage difference 12 - 450 V ---
VOUT Overall output voltage regulation 1.14 1.20 1.26 V 13.2V < VIN< 400V,
R1 = 2.4KΩ, R2 = 0
VOUT Overall output voltage regulation 375 400 425 V R1 = 2.4KΩ, R2 = 782KΩ
ΔVOUT Line regulation - 0.003 0.01 %/V 17V < VIN< 400V, VOUT = 5V,
IOUT = 0.5mA
ΔVOUT Load regulation - 1.4 3.0 % VIN = 17V, VOUT = 5V,
0.5mA <IOUT< 10mA
ΔVOUT Temperature regulation -1 - +1 % VIN = 17V, VOUT = 5V, IOUT = 10mA,
-40°C < TA < 85°C
IOUT Output current limit 10 - 30 mA TJ < 85°C, VIN - VOUT = 12V
IOUT Output current limit - - 0.5 mA TJ > 125°C, VIN - VOUT = 450V
TO-92 (N3)TO-252 (K4)
Product Marking
YY = Year Sealed
WW = Week Sealed
L = Lot Number
= “Green” Packaging
Si YYWW
LR8K4
LLLLLLL
Y = Last Digit of Year Sealed
W = Code for Week Sealed
L = Lot Number
= “Green” Packaging
SiLR
8
YWLL
TO-92 (N3)
TO-252 (K4)
Pin Congurations
LR8W W = Code for Week Sealed
= “Green” Packaging
TO-243AA (SOT-89) (N8)
Package may or may not include the following marks: Si or
Package may or may not include the following marks: Si or
Package may or may not include the following marks: Si or
VIN
ADJ
VOUT
ADJ
VIN
VOUT
VIN
ADJ
VOUT
VOUT
TO-243AA (SOT-89) (N8)
3
LR8
Supertex inc. ● 1235 Bordeaux Drive, Sunnyvale, CA 94089 ● Tel: 408-222-8888 ● www.supertex.com
Thermal Characteristics
Package Power Dissipation
@ TA = 25°C
θjc
°C/W
θja
°C/W
TO-92 0.74W 125 170
TO-243AA 1.6W 15 78†
TO-252 2.5W 6.25 50†
Note:
† Mounted on FR4 board, 25mm x 25mm x 1.57mm.
Functional Block Diagram
Overtemp &
Overcurrent 10µA1.2V
VIN VOUT
ADJ
LR8
Pass
Element
Sym Parameter Min Typ Max Units Conditions
IOUT Minimum output current - 0.3 0.5 mA Includes R1 and load current
IADJ Adjust output current 5.0 10 15 µA ---
C2 Minimum output load capacitance 1.0 - - µF ---
DVOUT/DVIN Ripple rejection ratio 50 60 - dB 120Hz, VOUT = 5V
TLIMIT Junction temperature limit 125 - - °C ---
Electrical Characteristics (cont.)
(Test conditions unless otherwise specied: -40°C < TA < 85°C.)
4
LR8
Supertex inc. ● 1235 Bordeaux Drive, Sunnyvale, CA 94089 ● Tel: 408-222-8888 ● www.supertex.com
Typical Application Circuits
Figure 2: SMPS Start-Up Circuit
Figure 3: High Voltage Adjustable Constant Current Source
LR8
+
VOUT1
-
VCC
VAUXILIARY
VIN = (VOUT + 12V) to 450V
VOUT
ADJ
VIN
FB PWM IC
+
VOUT1
-
LR8
VIN =
(VOUT + 12V) to 450V
R
Load
IOUT = 1.20V
R
+
-
1.0µF
VOUT
ADJ
VIN
LR8
VIN =
17 to 450V VOUT
ADJ
VIN
*
R1
6.04kΩ
1% C2
1.0µF
C1 RLOAD ≤16.5kΩ
VOUT = 5.0V
VOUT = 1.20V 1+ R2
R1 + IADJ R2
R2
18.2kΩ
1%
* Required for conditions where VIN is less than VOUT
Figure 1: High Input Voltage, 5.0V Output Linear Regulator
5
LR8
Supertex inc. ● 1235 Bordeaux Drive, Sunnyvale, CA 94089 ● Tel: 408-222-8888 ● www.supertex.com
Typical Performance Curves
12V
ADJ
V
IN
2.4k
Ω
1.0µF
V
OUT
= 1.2V
12V,
200V
400V
ADJ
VIN
2.4kΩ 1.0ΩF
VOUT = 1.2V
IADJ
VOUT (V)
T (junction) (OC)
Temperature Variation
-50 -25 0 25 50 75 100 125
1.00
1.05
1.10
1.15
1.20
1.25
1.30
Adjustment Current
I
ADJ
(µA)
T (junction) (
O
C)
-50 -25 0 25 50 75 100 125
6
7
8
9
10
11
12
V
IN
= 200V
VOUT (V)
IOUT (mA)
Load Regulation
0 2 4 6 8 10
4.8
4.9
5.0
5.1
5.2
ADJ
V
IN
6.04kΩ
±
1%
18.2kΩ
±
1%
1.0µFR
LOAD
V
OUT
= 5.0V
25V
I
OUT
LR8
LR8
LR8
V
IN
= 400V
V
IN
= 12V
6
LR8
Supertex inc. ● 1235 Bordeaux Drive, Sunnyvale, CA 94089 ● Tel: 408-222-8888 ● www.supertex.com
Typical Performance Curves (cont.)
ADJ
V
IN
6.04kΩ
±1%
18.2kΩ
±1%
1.0µF1kΩ
V
OUT
= 5.0V
0V to 50V
V
OUT
vs. V
IN
V
OUT
(V)
V
IN
(V)
01020304050
0
1
2
3
4
5
6
Ripple Rejection
Ripple Regection Ratio (dB)
I
OUT
(mA)
0 2 4 6 8 10
-60
-61
-62
-63
-64
-65
ADJ
VIN
6.04KΩ
±
1%
18.2KΩ
±
1%
1.0µF
RLOAD
VOUT = 5.0V
65V
IOUT
20VP-P
@ 60Hz
30
25
20
15
10
-40 -20 0 20 40 60 80 100
Temperature (OC)
lCL (mA)
LR8
LR8
7
LR8
Supertex inc. ● 1235 Bordeaux Drive, Sunnyvale, CA 94089 ● Tel: 408-222-8888 ● www.supertex.com
Typical Performance Curves (cont.)
Load Transient Response
Line Transient Response
Line Power Up Transient
Load Transient Response
Line Transient Response
ADJ
V
IN
6.04kΩ
±1%
18.2kΩ
±1%
1.0µF 10kΩ
V
OUT
= 5.0V
25V
LR8
532Ω
sw
ADJ
V
IN
6.04kΩ
±1%
18.2kΩ
±1%
1.0µF10kΩ
V
OUT
= 5.0V
LR8
400V
V
IN
0V
VOUT
Closed
SW
Open
400V
VIN
0V
VOUT
0V
400V
VIN
0V
5.0V
VOUT
0V
400V
VIN
0V
5.0V
VOUT
0V
Line Power Down Transient
8
LR8
Supertex inc. ● 1235 Bordeaux Drive, Sunnyvale, CA 94089 ● Tel: 408-222-8888 ● www.supertex.com
3-Lead TO-252 D-PAK Package Outline (K4)
Note:
1. Although 4 terminal locations are shown, only 3 are functional. Lead number 2 was removed.
123
4
L4 L5
b
b2
e
D1
E1
L1
L
Seating
Plane
A1
Gauge
Plane
θ
D
E
View B
Front View Side View
Rear View
View B
θ1
H
c2
A
L3
L2
b3
Note 1
Symbol A A1 b b2 b3 c2 D D1 E E1 e H L L1 L2 L3 L4 L5 θθ1
Dimen-
sion
(inches)
MIN .086 .000* .025 .030 .195 .018 .235 .205 .250 .170
.090
BSC
.370 .055
.108
REF
.020
BSC
.035 .025* .035†0O0O
NOM - - - - - - .240 - - - - .060 - - - - -
MAX .094 .005 .035 .045 .215 .035 .245 .217* .265 .200* .410 .070 .050 .040 .060 10O15O
JEDEC Registration TO-252, Variation AA, Issue E, June 2004.
* This dimension is not specied in the JEDEC drawing.
† This dimension differs from the JEDEC drawing.
Drawings not to scale.
Supertex Doc. #: DSPD-3TO252K4, Version F040910.
9
LR8
Supertex inc. ● 1235 Bordeaux Drive, Sunnyvale, CA 94089 ● Tel: 408-222-8888 ● www.supertex.com
3-Lead TO-92 Package Outline (N3)
Symbol A b c D E E1 e e1 L
Dimensions
(inches)
MIN .170 .014†.014†.175 .125 .080 .095 .045 .500
NOM - - - - - - - - -
MAX .210 .022†.022†.205 .165 .105 .105 .055 .610*
JEDEC Registration TO-92.
* This dimension is not specied in the JEDEC drawing.
† This dimension differs from the JEDEC drawing.
Drawings not to scale.
Supertex Doc.#: DSPD-3TO92N3, Version E041009.
Seating
Plane
1
2
3
Front View Side View
Bottom View
E1 E
D
e1
L
e
c
1 2 3
b
A
Supertex inc. does not recommend the use of its products in life support applications, and will not knowingly sell them for use in such applications unless it receives
an adequate “product liability indemnification insurance agreement.” Supertex inc. does not assume responsibility for use of devices described, and limits its liability
to the replacement of the devices determined defective due to workmanship. No responsibility is assumed for possible omissions and inaccuracies. Circuitry and
specifications are subject to change without notice. For the latest product specifications refer to the Supertex inc. (website: http//www.supertex.com)
©2011 Supertex inc. All rights reserved. Unauthorized use or reproduction is prohibited.
Supertex inc.
1235 Bordeaux Drive, Sunnyvale, CA
94089
Tel: 408-222-8888
www
.supertex.com
10
LR8
(The package drawing(s) in this data sheet may not reect the most current specications. For the latest package outline
information go to http://www.supertex.com/packaging.html.)
Doc.# DSFP-LR8
A030911
3-Lead TO-243AA (SOT-89) Package Outline (N8)
Symbol A b b1 C D D1 E E1 e e1 H L
Dimensions
(mm)
MIN 1.40 0.44 0.36 0.35 4.40 1.62 2.29 2.00†
1.50
BSC
3.00
BSC
3.94 0.73†
NOM-------- --
MAX 1.60 0.56 0.48 0.44 4.60 1.83 2.60 2.29 4.25 1.20
JEDEC Registration TO-243, Variation AA, Issue C, July 1986.
† This dimension differs from the JEDEC drawing
Drawings not to scale.
Supertex Doc. #: DSPD-3TO243AAN8, Version F111010.
bb1
D
D1
EHE1
C
A
12 3
e
e1
Top View Side View
L