Supertex inc. LR8 High Input Voltage, Adjustable 3-Terminal Linear Regulator Features General Description Applications Typical Application Circuit

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1 Supertex inc. High Input Voltage, Adjustable 3-Terminal Linear Regulator Features input voltage range Adjustable output regulation 5% output voltage tolerance Output current limiting 10µA typical 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 is a high voltage, low output current, adjustable linear regulator. It has a wide operating input voltage range of The output voltage can be adjusted from 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 regulates the voltage difference between and pins to a nominal value of 1.2. The 1.2 is amplified by the external resistor ratio R1 and R2. An internal constant bias current of typically 10µA is connected to the pin. This increases by a constant voltage of 10µA times R2. The 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 turns off when an external voltage greater than the output voltage of the is applied to of the. To maintain stability, a bypass capacitor of 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 * C 1 R 1 C 2 R LOAD R 2 * Required for conditions where is less than.

2 Ordering Information Device TO-252 (D-PAK) Package Options TO-92 TO-243AA (SOT-89) K4-G N3-G N8-G -G indicates package is RoHS compliant ( Green ) Pin Configurations TO-252 (K4) TO-92 (N3) Absolute Maximum Ratings Parameter Value input voltage (voltages ref to ) -0.5V to +48 Output voltage range -0.5V to +47 Operating ambient temperature range Operating junction temperature range Storage temperature range -40 C to +85 C -40 C to +125 C -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 specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Product Marking Si YYWW K4 LLLLLLL SiLR 8 YWLL TO-243AA (SOT-89) (N8) YY = Year Sealed WW = Week Sealed L = Lot Number = Green Packaging Package may or may not include the following marks: Si or TO-252 (K4) Y = Last Digit of Year Sealed W = Code for Week Sealed L = Lot Number = Green Packaging Package may or may not include the following marks: Si or TO-92 (N3) W W = Code for Week Sealed = Green Packaging Package may or may not include the following marks: Si or TO-243AA (SOT-89) (N8) Electrical Characteristics (Test conditions unless otherwise specified: -40 C < T A < 85 C.) Sym Parameter Min Typ Max Units Conditions - Input to output voltage difference V --- Overall output voltage regulation V 13.2V < < 40, R1 = 2.4KΩ, R2 = 0 Overall output voltage regulation V R1 = 2.4KΩ, R2 = 782KΩ Δ Line regulation %/V 17V < < 40, = 5V, = 0.5mA Δ Load regulation % = 17V, = 5V, 0.5mA < < 10mA Δ Temperature regulation % = 17V, = 5V, = 10mA, -40 C < T A < 85 C Output current limit ma T J < 85 C, - = 12V Output current limit ma T J > 125 C, - = 45 2

3 Electrical Characteristics (cont.) (Test conditions unless otherwise specified: -40 C < T A < 85 C.) Sym Parameter Min Typ Max Units Conditions Minimum output current ma Includes R1 and load current I Adjust output current µa --- C2 Minimum output load capacitance µf --- D /D Ripple rejection ratio db 120Hz, = 5V T LIMIT Junction temperature limit C --- Thermal Characteristics Package Power T A = 25 C TO W TO-243AA 1.6W TO W Note: Mounted on FR4 board, 25mm x 25mm x 1.57mm. θ jc C/W θ ja C/W Functional Block Diagram Pass Element Overtemp & Overcurrent 1.2V 10µA 3

4 Typical Application Circuits Figure 1: High Input Voltage, 5. Output Linear Regulator * = 17 to 45 C1 R2 18.2kΩ 1% R1 6.04kΩ 1% C2 R LOAD 16.5kΩ * Required for conditions where is less than = R2 R1 + I R2 Figure 2: SMPS Start-Up Circuit = ( + 12V) to 45 V AUXILIARY V CC FB PWM IC Figure 3: High Voltage Adjustable Constant Current Source + = ( + 12V) to 45 - R = 1.2 R Load 4

5 Typical Performance Curves 1.30 Temperature Variation = 1.2V V 2.4kΩ (V) T (junction) ( O C) 12 Adjustment Current 11 = 1.2V 10 12V, I 2.4kΩ 1.0ΩF I (µa) 9 8 = 40 = 12V 7 = T (junction) ( O C) 5.2 Load Regulation kΩ 25V R LOAD (V) kΩ (ma) 5

6 Typical Performance Curves (cont.) 6 vs kΩ 4 to kΩ 1kΩ (V) (V) -65 Ripple Rejection 2 60Hz 65V 18.2KΩ 6.04KΩ R LOAD Ripple Regection Ratio (db) (ma) l CL (ma) Temperature ( O C) 6

7 Typical Performance Curves (cont.) Load Transient Response 6.04kΩ sw Closed SW Open 25V 10kΩ 18.2kΩ 532Ω Load Transient Response Line Transient Response kΩ 10kΩ 18.2kΩ Line Transient Response Line Power Up Transient Line Power Down Transient 7

8 3-Lead TO-252 D-PAK Package Outline (K4) E b3 E1 A c2 4 L3 θ1 D1 H D L4 L5 Note 1 b2 e b View B Front View Rear View Side View L2 Gauge Plane A1 Seating Plane θ L L1 View B Note: 1. Although 4 terminal locations are shown, only 3 are functional. Lead number 2 was removed. Dimension (inches) Symbol A A1 b b2 b3 c2 D D1 E E1 e H L L1 L2 L3 L4 L5 θ θ1 MIN * * O 0 O NOM BSC REF BSC MAX * * O 15 O JEDEC Registration TO-252, Variation AA, Issue E, June * This dimension is not specified in the JEDEC drawing. This dimension differs from the JEDEC drawing. Drawings not to scale. Supertex Doc. #: DSPD-3TO252K4, Version F

9 3-Lead TO-92 Package Outline (N3) D Seating Plane A L b e1 e Front View c Side View E1 1 3 E 2 Bottom View Dimensions (inches) Symbol A b c D E E1 e e1 L MIN NOM MAX * JEDEC Registration TO-92. * This dimension is not specified in the JEDEC drawing. This dimension differs from the JEDEC drawing. Drawings not to scale. Supertex Doc.#: DSPD-3TO92N3, Version E

10 3-Lead TO-243AA (SOT-89) Package Outline (N8) D D1 C E H E1 L b e e1 b1 A Top View Side View Dimensions (mm) (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to 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// Supertex inc. All rights reserved. Unauthorized use or reproduction is prohibited. Doc.# DSFP- A Symbol A b b1 C D D1 E E1 e e1 H L MIN NOM BSC BSC - - MAX JEDEC Registration TO-243, Variation AA, Issue C, July This dimension differs from the JEDEC drawing Drawings not to scale. Supertex Doc. #: DSPD-3TO243AAN8, Version F Supertex inc Bordeaux Drive, Sunnyvale, CA Tel: