Ordering number : ENA2086 LA5797MC Monolithic Linear IC Charge Pump Step-up Power Supply for Variable Capacitance Diodes http://onsemi.com Overview The LA5797MC is a charge pump step-up power supply for Variable capacitance diodes. Features • By using charge pump, no coils are necessary. • Time-base generator (140kHz) incorporated. • Thermal shutdown circuit incorporated. Specifications Maximum Ratings at Ta = 25°C Parameter Symbol Input voltage VIN max Allowable power dissipation Pd max Conditions Ratings Mounted on the specified board. * Unit 30 V 0.75 W Operating temperature Topr -25 to +90 °C Storage temperature Tstg -40 to +150 °C Junction temperature Tjmax 150 °C * Specified board: 114.3mm × 76.1mm × 1.6mm, glass epoxy board. Caution 1) Absolute maximum ratings represent the value which cannot be exceeded for any length of time. Caution 2) Even when the device is used within the range of absolute maximum ratings, as a result of continuous usage under high temperature, high current, high voltage, or drastic temperature change, the reliability of the IC may be degraded. Please contact us for the further details. Stresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the Recommended Operating Conditions is not implied. Extended exposure to stresses above the Recommended Operating Conditions may affect device reliability. Recommended Operating Conditions at Ta = 25°C Parameter Input voltage range Symbol VIN Semiconductor Components Industries, LLC, 2013 August, 2013 Conditions Ratings Unit 7.5 to 28 V 62012 SY 20120207-S00003 No.A2086-1/4 LA5797MC Electrical Characteristics at Ta = 25°C Parameter Symbol Ratings Conditions min Reference voltage VFB Switching frequency VIN = 15V, IO = 5mA f Thermal shutdown operating VIN = 7.5V to 28V Unit typ max 1.189 1.225 1.261 112 140 168 V kHz TSD Designed target value. * 165 °C ΔTSD Designed target value. * 15 °C temperature Thermal shutdown Hysteresis width * Design target value: No measurement made. Package Dimensions unit : mm (typ) 3424 4.9 8 Allowable power dissipation, Pd max -- W 0.835 0.375 2 0.42 0.2 1.75 MAX 1.27 6.0 3.9 1 Pd max -- Ta 1.0 Specified board: 114.3×76.1×1.6mm3 glass epoxy board. 0.8 0.75 0.6 0.4 0.36 0.2 0.175 0 -25 0 25 50 75 90 100 125 Ambient temperature, Ta -- °C SANYO : SOIC8 Pin Assignment VIN 1 8 VRET EN 2 7 CPOUT NC 3 6 GND NC 4 5 FB Top view No.A2086-2/4 LA5797MC Block Diagram VRET VIN Reg. DRIVE ON/OFF OSC EN VREF CPOUT Amp. DRIVE ON/OFF NC FB NC TSD GND Application Circuit Example External circuit diagram (VCC = 24V) VRET VCC 24V CPOUT LA5797MC 31-32V EN FB GND No.A2086-3/4 LA5797MC External circuit diagram (VCC = 15V) VRET VCC 15V CPOUT LA5797MC 31-32V EN FB GND Note : The IC is made active when the EN pin is pulled down to GND. The charge pump operation is stopped when the EN pin is pulled up to VIN. ON Semiconductor and the ON logo are registered trademarks of Semiconductor Components Industries, LLC (SCILLC). SCILLC owns the rights to a number of patents, trademarks, copyrights, trade secrets, and other intellectual property. A listing of SCILLC’s product/patent coverage may be accessed at www.onsemi.com/site/pdf/Patent-Marking.pdf. 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. This literature is subject to all applicable copyright laws and is not for resale in any manner. PS No.A2086-4/4