LR8 High Input Voltage Adjustable 3-Terminal Linear Regulator Features General Description ► ► ► ► ► ► The Supertex LR8 is a high voltage, low output current, adjustable linear regulator. It has a wide operating input voltage range of 13.2V to 450V. The output voltage can be adjusted from 1.20V to 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 amplified 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. 13.2V to 450V input voltage range Adjustable 1.20V to 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 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 (DPAK), and TO-92 packages. Typical Application Circuit * VOUT VIN VIN VOUT ADJ LR8 R1 C2 C1 R2 *Required for conditions where VIN is less than VOUT. RLOAD LR8 Ordering Information DEVICE LR8 Package Option TO-243AA TO-252 TO-92 LR8N8-G LR8K4-G LR8N3-G -G indicates package is RoHS compliant (‘Green’) Pin Configurations Absolute Maximum Ratings VOUT VOUT 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 VIN ADJ VOUT VIN ADJ VIN TO-243AA (SOT-89) TO-252 (D-PAK) 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. (top view) (top view) VOUT ADJ TO-92 (front view) Product Marking Product marking for TO-243AA: LR8 where Electrical Characteristics (Test conditions unless otherwise specified: Symbol Parameter VIN - VOUT = 2-week alpha date code -40°C < TA < 85°C.) Min Typ Max 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 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 IOUT Minimum output current - 0.3 0.5 mA Includes R1 and load current IADJ Adjust output current 5 10 15 µA --- C2 Minimum output load capacitance 1 - - µF --- DVOUT/DVIN Ripple rejection ratio 50 60 - dB 120Hz, VOUT = 5V TLIMIT Junction temperature limit 125 - - °C --- 2 Units Conditions 17V < VIN< 400V, VOUT = 5V, IOUT = 0.5mA LR8 Thermal Characteristics 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† Package †Mounted on FR4 board, 25mm x 25mm x 1.57mm. Significant PD increase possible on ceramic substrate. Functional Block Diagram VIN LR8 Pass Element Overtemp & Overcurrent 1.2V VOUT 10µA ADJ Typical Application Circuits Figure 1: High Input Voltage, 5.0V Output Linear Regulator * VOUT = 5.0V VIN = 17V to 450V VIN VOUT ADJ LR8 R1 6.04KΩ 1% C1 R2 18.2KΩ 1% * Required for conditions where VIN is less than VOUT 3 C2 1.0µF RLOAD ≤16.5KΩ R2 VOUT = 1.20V 1+ R1 + IADJ R2 LR8 Typical Application Circuits Figure 2: SMPS Start-Up Circuit VIN = (VOUT + 12V) to 450V + VAUXILIARY VOUT1 - VIN VOUT + ADJ VOUT2 LR8 VCC FB PWM IC Figure 3: High Voltage Adjustable Constant Current Source IOUT = R + VIN 1.20V R VOUT ADJ VIN = (VOUT + 12V) to 450V LR8 LOAD 1.0µF - 4 LR8 Typical Performance Curves Temperature Variation 1.30 VIN 1.25 VOUT = 1.2V VOUT (V) LR8 ADJ 12V 2.4KΩ 1.0µF 1.20 1.15 1.10 1.05 1.00 -50 -25 0 25 50 75 100 125 100 125 T(junction) ( OC) Adjustment Current 12 11 VOUT = 1.2V IADJ (µA) VIN LR8 12V, 200V, 400V ADJ 2.4KΩ 10 VIN = 400V VIN = 12V 9 1.0ΩF I 8 ADJ VIN = 200V 7 6 -50 -25 0 25 50 75 T(junction) (OC) Load Regulation 5.2 V V IN OUT = 5.0V IOUT LR8 5.1 ADJ 25V 1.0µF VOUT (V) 6.04KΩ ±1% 5.0 RLOAD 18.2KΩ ±1% 4.9 4.8 0 2 4 6 IOUT (mA) 5 8 10 LR8 Typical Performance Curves (cont.) VOUT vs. VIN 6 VOUT = 5.0V VIN 5 VOUT (V) LR8 6.04KΩ ±1% ADJ 1.0µF 0V to 50V 1KΩ 18.2KΩ ±1% 4 3 2 1 0 0 10 20 30 40 50 8 10 VIN (V) Ripple Rejection VIN 20VP-P @ 60Hz LR8 VOUT = 5.0V ADJ Ripple Rejection Ratio (dB) -65 IOUT 6.04KΩ ±1% 1.0µF RLOAD 18.2KΩ ±1% -63 -62 -61 -60 0 2 4 6 I OUT (mA) 30 25 l c l (m A ) 65V -64 20 15 10 -40 -20 0 20 40 Temperature (°C) 6 60 80 100 LR8 Typical Performance Curves (cont.) LR8 ± Ω Ω ± Ω Ω Load Transient Response LR8 ± Ω Ω ± Ω Line Transient Response Line Power Up Transient Line Power Down Transient 7 LR8 3-Lead TO-243AA (SOT-89) Package Outline (N8) 4.50 ± 0.10 1.50 ± 0.10 0.40 ± 0.05 1.72 ± 0.10 Exclusion Zone No Vias/Traces in this area. Shape of pad may vary. 4.10 ± 0.15 2.21 ± 0.08 2.45 ± 0.15 1.05 ± 0.15 0.5 ± 0.06 0.42 ± 0.06 1.50 BSC 3.00 BSC Top View Bottom View Side View Notes: All dimensions are in millimeters; all angles in degrees. 3-Lead TO-252 (D-PAK) Package Outline (K4) 0.250 - 0.265 0.086 - 0.094 0.195 -0.215 0.035 - 0.050 0.018 - 0.035 4 0O - 15O 0.370 - 0.410 0.240 ± 0.005 0.005 MAX 0.040 MAX 1 2 3 0.047 - 0.070 0.108 REF 0.030 - 0.045 0O - 10O 0.090 BSC 0.025 - 0.035 0.018 - 0.024 0.170 MIN 0.20 BSC Cutouts may not be present 4 0.205 MIN Notes: All dimensions in inches; angles in degrees 3 2 1 8 LR8 3-Lead TO-92 Package Outline (N3) 0.135 MIN 0.125 - 0.165 0.080 - 0.105 1 2 3 Top View 0.175 - 0.205 0.170 - 0.210 Seating Plane 1 2 3 0.500 MIN 0.014 - 0.022 0.014 - 0.022 0.045 - 0.055 0.095 - 0.105 Front View Side View Notes: All dimensions are in millimeters; all angles in degrees. (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to http://www.supertex.com/packaging.html.) Doc.# DSFP-LR8 A121806 9