LR12 LR12 Initial Release High Input Voltage Adjustable 3-Terminal Linear Regulator Features General Description ❏ ❏ ❏ ❏ ❏ ❏ ❏ ❏ The Supertex LR12 is a high voltage, low output current, adjustable linear regulator. It has a wide operating input voltage range of 13.2V to 100V. The output voltage can be adjusted from 1.20V to 88V 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 LR12 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 100V Input Voltage Range Stable with 100nF output capacitor Adjustable 1.20V to 88V output regulation 5% reference voltage tolerance Output current limiting, 50mA min. 10µA typical ADJ current Over temperature protection Available in 3 different packages Applications ❏ ❏ ❏ ❏ ❏ ❏ ❏ ❏ ❏ The LR12 has current limiting and temperature limiting. The output current limit is 100mA maximum and the minimum temperature limit is 125°C. An output short circuit current will therefore be limited to 100mA maximum. 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 LR12 turns off when an external voltage greater than the output voltage of the LR12 is applied to VOUT of the LR12. To maintain stability, a bypass capacitor of 100nF or larger and a minimum DC output current of 500µA are required. DC/DC SMPS startup circuits Adjustable high voltage constant current sources Industrial Controls Motor Controls Battery Powered Systems Power Supplies Telecom Applications LED Drivers The device is available in TO-92, SO-8, and TO-252 (D-PAK) packages. Automotive Applications LR12 Typical Application * VIN 13.2V to 100V VIN VOUT =1.2V to 88V VOUT ADJ R1 LR12 C2 C1 RLOAD R2 *Required for conditions where VIN is less than VOUT. 06/11/03 Supertex Inc. does not recommend the use of its products in life support applications and will not knowingly sell its products for use in such applications unless it receives an adequate "products liability indemnification insurance agreement." Supertex does not assume responsibility for use of devices described and limits its liability to the replacement of devices determined to be defective due to workmanship. No responsibility is assumed for possible omissions or inaccuracies. Circuitry and specifications are subject to change without notice. For the latest product specifications, refer to the Supertex website: http://www.supertex.com. For complete liability information on all Supertex products, 1 refer to the most current databook or to the Legal/Disclaimer page on the Supertex website. LR12 Ordering Information Package Options SO-8 TO-252 TO-92 LR12LG LR12K4 LR12N3 Pin Configurations Absolute Maximum Ratings VIN-ADJ -0.5V to +120V VOUT-ADJ VOUT ADJ NC NC VIN -10V to +10V VIN – VOUT -0.5V to +120V 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 1 8 2 7 3 6 4 5 VOUT VOUT VOUT VOUT VIN ADJ TO-252 (D-PAK) SO-8 ADJ VOUT VIN TO-92 Electrical Characteristics Test conditions unless otherwise specified: -40°C < TA < 85°C. Symbol Parameter Min VIN - VOUT Input to Output Voltage Difference 12 VOUT Overall Output Voltage Regulation 1.14 ∆VOUT Typ Max Units 98.8 V 1.20 1.26 V Line Regulation 0.003 0.01 %/V 15V<VIN<100V, VOUT=5V, IOUT=0.5mA ∆VOUT Load Regulation 1.4 3.0 % VIN=15V, VOUT=5V, 0.5mA<IOUT<50mA ∆VOUT Temperature Regulation +1 % VIN=15V, VOUT=5V, IOUT=10mA, -1 Test Conditions 13.2V<VIN<100V, R1=2.4KΩ, R2=0 -40°C<TA<85°C IOUT Output Current Limit IOUT Output Current Limit IOUT Minimum Output Current IADJ Adjust Output Current C2 Minimum Output Load Capacitance DVOUT/DVIN Ripple Rejection Ratio TLIMIT Junction Temperature Limit 50 100 mA TJ < 85°C, VIN - VOUT = 12V 0.5 mA TJ > 125°C, VIN - VOUT = 100V mA Includes R1 and load current 0.5 5 10 100 50 15 µA nF 60 125 dB °C 2 120Hz, VOUT = 5V LR12 Thermal Characteristics Power Dissipation @ TA=25°C θJC θJA °C/W °C/W TO-92 0.6W 125 170 SO-8 1.8W — 55† TO-252 2.0W 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 LR12 Pass Element Overtemp & Overcurrent VOUT 6.5V 1KΩ 1.2V 3 10µA ADJ LR12 Typical Application Circuits * V VIN=17V to 100V VOUT=5.0V VOUT IN ADJ R1 6.04KΩ ±1% LR12 C1 C2 100nF RLOAD ≤16.5KΩ R2 18.2KΩ ±1% VOUT = 1.20V 1+ R2 + IADJ R2 R1 Figure 1: High Input Voltage, 5.0V Output Linear Regulator * Required for conditions where VIN is less than VOUT. VIN=15V to 100V + VAuxiliary Vout1 - LR12 VIN + VOUT ADJ Vout2 - Vcc FB PWM IC Figure 2: SMPS Start-Up Circuit IOUT = LR12 + VIN 1.20V R VOUT R ADJ VIN = 15V to 100V 100nF - Figure 3: High Voltage Adjustable Constant Current Source 4 LR12 Typical Performance Curves Temperature Variation 1.30 VIN 1.25 LR12 ADJ 2.4KΩ 13.2V 100nF VOUT (V) VOUT=1.2V 1.20 1.15 1.10 1.05 1.00 -50 -25 0 25 50 75 100 125 T(junction) (°C) Load Regulation 5.30 5.25 VIN VOUT=5.0V IOUT 5.20 LR12 5.15 6.04KΩ ±1% 100nF 25V VOUT (V) ADJ RLOAD 18.2KΩ ±1% 5.10 5.05 5.00 4.95 4.90 4.85 4.80 0 5 10 15 20 25 30 IOUT (mA) 5 35 40 45 50 LR12 Typical Performance Curves VOUT vs. VIN 6 V V IN OUT =5.0V 5 ADJ VOUT (V) LR12 6.04KΩ ±1% 100nF 0V to 50V 1KΩ 18.2KΩ ±1% 4 3 2 1 0 0 20 40 60 80 100 VIN (V) Ripple Rejection -65 IOUT Ripple Rejection Ratio (dB) VOUT =5.0V VIN LR12 20VP-P @ 120Hz ADJ 6.04KΩ ±1% 100nF RLOAD 65V 18.2KΩ ±1% -64 -63 -62 -61 -60 0 10 20 30 40 IOUT (mA) Current Limit 100 Ic (mA) 90 80 70 60 50 -40 -20 0 20 40 Temperature (°C) 6 60 80 100 50 LR12 Typical Performance Curves Load Transient Response V SW VOUT=5.0V IN Closed LR12 ADJ 6.04KΩ ±1% SW 100nF 25V Open 10KΩ 18.2KΩ ±1% 509Ω VOUT 200mV/div Load Transient Response, Load=509Ω Line Transient Response 100V VOUT VIN VIN LR12 0V ADJ 6.04KΩ ±1% 100nF 10KΩ 18.2KΩ ±1% VIN 50V/div VOUT 5V/div Line Turn On/Off Response VIN 50V/div VIN 50V/div VOUT 5V/div VOUT 5V/div Line Power Up Transient Line Power Down Transient 06/16/03rev.5 ©2003 Supertex Inc. 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