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| MC34268 SCSI-2 Active Terminator Regulator The MC34268 is a medium current, low dropout positive voltage regulator specifically designed for use in SCSI-2 active termination circuits. This device offers the circuit designer an economical solution for precision voltage regulation, while keeping power losses to a minimum. The regulator consists of a 1.0 V dropout composite PNP/NPN pass transistor, current limiting, and thermal limiting. These devices are packaged in the 8-pin SOP-8 and 3-pin DPAK and SOT-223 surface mount power packages. Applications include active SCSI-2 terminators and post regulation of switching power supplies. http://onsemi.com MARKING DIAGRAMS 8 8 1 SOP-8 D SUFFIX CASE 751 1 A L Y W = Assembly Location = Wafer Lot = Year = Work Week 1 2 8 7 6 5 (Top View) NC 34268 ALYW * * * * * * * * 2.85 V Output Voltage for SCSI-2 Active Termination 1.0 V Dropout Output Current in Excess of 800 mA Thermal Protection Short Circuit Protection Output Trimmed to 1.4% Tolerance No Minimum Load Required Space Saving DPAK, SOT-223 and SOP-8 Surface Mount Power Packages Simplified Block Diagram Input 1 3 Gnd Output Output NC 3 Input 4 DPAK DT SUFFIX CASE 369A 34268 ALYWW Thermal Limiting Control Circuit 1 Current Limit 3 SOT-223 ST SUFFIX CASE 318E AYW 268ST Output 4 1 2 3 Pin 1. Ground 2. Output 3. Input 4. Output (Top View) Ground Heatsink surface (shown as terminal 4 in case outline drawing) is connected to Pin 2. ORDERING INFORMATION See detailed ordering and shipping information in the package dimensions section on page 3 of this data sheet. (c) Semiconductor Components Industries, LLC, 2000 1 April, 2000 - Rev. 1 Publication Order Number: MC34268/D MC34268 MAXIMUM RATINGS Rating Power Supply Input Voltage Power Dissipation and Thermal Characteristics DT Suffix, Plastic Package, Case 369A TA = 25C, Derate Above TA = 25C Thermal Resistance, Junction-to-Case Thermal Resistance, Junction-to-Air D Suffix, Plastic Package, Case 751 TA = 25C, Derate Above TA = 25C Thermal Resistance, Junction-to-Case Thermal Resistance, Junction-to-Air ST Suffix, Plastic Package, Case 318E TA = 25C, Derate Above TA = 25C Thermal Resistance, Junction-to-Case Thermal Resistance, Junction-to-Air Operating Junction Temperature Range Storage Temperature Symbol Vin Value 15 Unit V PD RJC RJA PD RJC RJA PD RJC RJA TJ Tstg Internally Limted 5.0 87 Internally Limited 22 140 Internally Limited 15 245 0 to +150 - 55 to +150 W C/W C/W W C/W C/W W C/W C/W C C ELECTRICAL CHARACTERISTICS (Vin = 4.25 V, CO = 10 F, for typical values TJ = 25C, for min/max values TJ = 0C to +125C, unless otherwise noted.) Characteristic Output Voltage (TJ = 25C, IO = 0 mA) Output Voltage, over Line, Load, and Temperature (Vin = 3.9 V to 15 V, IO = 0 mA to 490 mA) Line Regulation (Vin = 4.25 V to 15 V, IO = 0 mA, TJ = 25C) Load Regulation (IO = 0 mA to 800 mA, TJ = 25C) Dropout Voltage (IO = 490 mA) Ripple Rejection (f = 120 Hz) Maximum Output Current (Vin = 5.0 V) Bias Current (Vin = 4.25 V, IO = 0 mA) Minimum Load Current to maintain Regulation (Vin = 15 V) Symbol VO Min 2.81 2.76 -- -- -- 55 800 -- -- Typ 2.85 2.85 -- -- 0.95 -- -- 5.0 to 3.0 -- Max 2.89 2.93 0.3 0.5 1.1 -- -- 8.0 0 Unit V Regline Regload Vin - VO RR I(max) IB IL(min) I O , OUTPUT CURRENT VO , OUTPUT VOLTAGE DEVIATION % % V dB mA mA mA Figure 1. Dropout Voltage versus Output Load Current 1.5 V in-VO , DROPOUT VOLTAGE (V) TJ = 25C 1.3 1.1 0.9 0.7 0.5 Figure 2. Transient Load Regulation Vin = 5.0 V CO = 10 F TA = 25C 0 200 400 600 800 1000 20 ms/DIV IO, OUTPUT LOAD CURRENT (mA) http://onsemi.com 2 MC34268 Figure 3. Typical SCSI Application Vin 1N5819 10 MC34268 SCSI Regulator Gnd VO CO 10 To SCSI Bus 110 5.0V Figure 3 is a circuit of a typical SCSI terminator application. The MC34268 is designed specifically to provide 2.85 V required to drive a SCSI-2 bus. The output current capability of the regulator is in excess of 800 mA; enough to drive standard SCSI-2, fast SCSI-2, and some wide SCSI-2 applications. The typical dropout voltage is less than 1.0 V, allowing the IC to regulate to input voltages less than 4.0 V. Internal protective features include current and thermal limiting. JA, THERMAL RESISTANCE JUNCTION-TO-AIR ( C/W) The MC34268 requires an external 10 F capacitor with an ESR of less than 10 for stability over temperature. With economical electrolytic capacitors, cold temperature operation can pose a stability problem. As temperature decreases, the capacitance also decreases and the ESR increases, which could cause the circuit to oscillate. Tantalum capacitors may be a better choice if small size is a requirement. Also, the capacitance and ESR of a tantalum capacitor is more stable over temperature. JA, THERMAL RESISTANCE JUNCTION-TO-AIR ( C/W) Figure 4. SOP-8 Thermal Resistance versus P.C.B. Copper Length 180 160 L Figure 5. DPAK Thermal Resistance versus P.C.B. Copper Length 90 P.C. Board Heatsink Example 120 80 40 0 L 9.0 mm L 70 60 50 40 0 10 20 30 40 50 L, LENGTH OF COPPER FLAGS (mm) 60 70 0 10 20 30 L, LENGTH OF COPPER (mm) ORDERING INFORMATION Device MC34268D MC34268DR2 MC34268DT MC34268DTRK MC34268STT3 Package SO-8 SO-8 DPAK DPAK SOT-223 Shipping Information 98 Units / Rail 2500 Units / Tape & Reel 75 Units / Rail 2500 Units / Tape & Reel 4000 Units / Tape & Reel http://onsemi.com 3 EEEEE EEEEE EEEEE EEEEE 2.0 oz Copper L EEEEE EEEEE EEEEE 2.0 oz Copper P.C. Board Heatsink Example 80 L 40 MC34268 PACKAGE DIMENSIONS SOP-8 D SUFFIX CASE 751-06 ISSUE T NOTES: 1. DIMENSIONING AND TOLERANCING PER ASME Y14.5M, 1994. 2. DIMENSIONS ARE IN MILLIMETER. 3. DIMENSION D AND E DO NOT INCLUDE MOLD PROTRUSION. 4. MAXIMUM MOLD PROTRUSION 0.15 PER SIDE. 5. DIMENSION B DOES NOT INCLUDE DAMBAR PROTRUSION. ALLOWABLE DAMBAR PROTRUSION SHALL BE 0.127 TOTAL IN EXCESS OF THE B DIMENSION AT MAXIMUM MATERIAL CONDITION. DIM A A1 B C D E e H h L MILLIMETERS MIN MAX 1.35 1.75 0.10 0.25 0.35 0.49 0.19 0.25 4.80 5.00 3.80 4.00 1.27 BSC 5.80 6.20 0.25 0.50 0.40 1.25 0_ 7_ A 8 D 5 C E 1 4 H 0.25 M B M h B C e A SEATING PLANE X 45 _ q L 0.10 A1 B 0.25 M CB S A S q DPAK DT SUFFIX CASE 369A-13 ISSUE Z -T- B V R 4 SEATING PLANE NOTES: 1. DIMENSIONING AND TOLERANCING PER ANSI Y14.5M, 1982. 2. CONTROLLING DIMENSION: INCH. INCHES MIN MAX 0.235 0.250 0.250 0.265 0.086 0.094 0.027 0.035 0.033 0.040 0.037 0.047 0.180 BSC 0.034 0.040 0.018 0.023 0.102 0.114 0.090 BSC 0.175 0.215 0.020 0.050 0.020 --- 0.030 0.050 0.138 --- MILLIMETERS MIN MAX 5.97 6.35 6.35 6.73 2.19 2.38 0.69 0.88 0.84 1.01 0.94 1.19 4.58 BSC 0.87 1.01 0.46 0.58 2.60 2.89 2.29 BSC 4.45 5.46 0.51 1.27 0.51 --- 0.77 1.27 3.51 --- C E A S 1 2 3 Z U K F L D G 2 PL J H 0.13 (0.005) T DIM A B C D E F G H J K L R S U V Z M http://onsemi.com 4 MC34268 PACKAGE DIMENSIONS SOT-223 ST SUFFIX CASE 318E-04 ISSUE K A F 4 NOTES: 1. DIMENSIONING AND TOLERANCING PER ANSI Y14.5M, 1982. 2. CONTROLLING DIMENSION: INCH. S 1 2 3 B D L G J C 0.08 (0003) H M K INCHES DIM MIN MAX A 0.249 0.263 B 0.130 0.145 C 0.060 0.068 D 0.024 0.035 F 0.115 0.126 G 0.087 0.094 H 0.0008 0.0040 J 0.009 0.014 K 0.060 0.078 L 0.033 0.041 M 0_ 10 _ S 0.264 0.287 MILLIMETERS MIN MAX 6.30 6.70 3.30 3.70 1.50 1.75 0.60 0.89 2.90 3.20 2.20 2.40 0.020 0.100 0.24 0.35 1.50 2.00 0.85 1.05 0_ 10 _ 6.70 7.30 http://onsemi.com 5 MC34268 Notes http://onsemi.com 6 MC34268 Notes http://onsemi.com 7 MC34268 ON Semiconductor and are trademarks of Semiconductor Components Industries, LLC (SCILLC). SCILLC reserves the right to make changes without further notice to any products herein. SCILLC makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does SCILLC assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation special, consequential or incidental damages. "Typical" parameters which may be provided in SCILLC data sheets and/or specifications can and do vary in different applications and actual performance may vary over time. All operating parameters, including "Typicals" must be validated for each customer application by customer's technical experts. SCILLC does not convey any license under its patent rights nor the rights of others. SCILLC products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other applications intended to support or sustain life, or for any other application in which the failure of the SCILLC product could create a situation where personal injury or death may occur. Should Buyer purchase or use SCILLC products for any such unintended or unauthorized application, Buyer shall indemnify and hold SCILLC and its officers, employees, subsidiaries, affiliates, and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized use, even if such claim alleges that SCILLC was negligent regarding the design or manufacture of the part. SCILLC is an Equal Opportunity/Affirmative Action Employer. PUBLICATION ORDERING INFORMATION NORTH AMERICA Literature Fulfillment: Literature Distribution Center for ON Semiconductor P.O. Box 5163, Denver, Colorado 80217 USA Phone: 303-675-2175 or 800-344-3860 Toll Free USA/Canada Fax: 303-675-2176 or 800-344-3867 Toll Free USA/Canada Email: ONlit@hibbertco.com Fax Response Line: 303-675-2167 or 800-344-3810 Toll Free USA/Canada N. American Technical Support: 800-282-9855 Toll Free USA/Canada EUROPE: LDC for ON Semiconductor - European Support German Phone: (+1) 303-308-7140 (M-F 1:00pm to 5:00pm Munich Time) Email: ONlit-german@hibbertco.com French Phone: (+1) 303-308-7141 (M-F 1:00pm to 5:00pm Toulouse Time) Email: ONlit-french@hibbertco.com English Phone: (+1) 303-308-7142 (M-F 12:00pm to 5:00pm UK Time) Email: ONlit@hibbertco.com EUROPEAN TOLL-FREE ACCESS*: 00-800-4422-3781 *Available from Germany, France, Italy, England, Ireland CENTRAL/SOUTH AMERICA: Spanish Phone: 303-308-7143 (Mon-Fri 8:00am to 5:00pm MST) Email: ONlit-spanish@hibbertco.com ASIA/PACIFIC: LDC for ON Semiconductor - Asia Support Phone: 303-675-2121 (Tue-Fri 9:00am to 1:00pm, Hong Kong Time) Toll Free from Hong Kong & Singapore: 001-800-4422-3781 Email: ONlit-asia@hibbertco.com JAPAN: ON Semiconductor, Japan Customer Focus Center 4-32-1 Nishi-Gotanda, Shinagawa-ku, Tokyo, Japan 141-8549 Phone: 81-3-5740-2745 Email: r14525@onsemi.com ON Semiconductor Website: http://onsemi.com For additional information, please contact your local Sales Representative. http://onsemi.com 8 MC34268/D |
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