Ordering number : ENA0476A Monolithic Linear IC LA5779 Separately-excited Step-down Switching Regulator (Variable Type) Overview The LA5779 is a Separately-excited step-down switching regulator (variable type). Functions • High efficiency. • Six external parts. • Time-base generator (160kHz) incorporated. • Current limiter incorporated. • Thermal shutdown circuit incorporated. • ON/OFF function. Specifications Absolute Maximum Ratings at Ta = 25°C Parameter Symbol Maximum Input voltage VIN max 30 V IO max 3 A Maximum Output current SW pin application reverse voltage Allowable power dissipation Conditions Ratings VSW Pd max1 Infinitely large heat sink. Pd max2 Independent IC. Unit -1 V 7.5 W 1.75 W °C Operating temperature Topr -30 to +125 Storage temperature Tstg -40 to +150 °C Junction temperature Tj max 150 °C Recommended Operating Conditions at Ta = 25°C Parameter Input voltage range Symbol VIN Conditions Ratings Unit 4.5 to 28 V Any and all SANYO Semiconductor Co.,Ltd. products described or contained herein are, with regard to "standard application", intended for the use as general electronics equipment (home appliances, AV equipment, communication device, office equipment, industrial equipment etc.). The products mentioned herein shall not be intended for use for any "special application" (medical equipment whose purpose is to sustain life, aerospace instrument, nuclear control device, burning appliances, transportation machine, traffic signal system, safety equipment etc.) that shall require extremely high level of reliability and can directly threaten human lives in case of failure or malfunction of the product or may cause harm to human bodies, nor shall they grant any guarantee thereof. If you should intend to use our products for applications outside the standard applications of our customer who is considering such use and/or outside the scope of our intended standard applications, please consult with us prior to the intended use. If there is no consultation or inquiry before the intended use, our customer shall be solely responsible for the use. Specifications of any and all SANYO Semiconductor Co.,Ltd. products described or contained herein stipulate the performance, characteristics, and functions of the described products in the independent state, and are not guarantees of the performance, characteristics, and functions of the described products as mounted in the customer' s products or equipment. To verify symptoms and states that cannot be evaluated in an independent device, the customer should always evaluate and test devices mounted in the customer' s products or equipment. 62707 MS PC 20070619-S00001 / N1306 MS PC 20060606-S00001 No.A0476-1/4 LA5779 Electrical Characteristics at Ta = 25°C, VO = 3.3V Parameter Symbol Ratings Conditions min Reference voltage VOS 1.20 max 1.23 1.26 V η VIN = 15V, IO = 1.0A, Set VO = 5V f VIN = 15V, IO = 1.0A 128 160 192 kHz fshort VIN = 15V, VOS = 0V 15 30 45 kHz 40 100 mV 10 30 Efficiency Switching frequency Switching frequency when VIN = 15V, IO = 1.0A Unit typ 84 % short-circuit protection is active Line regulation ∆VOLINE VIN = 8 to 20V, IO = 1.0A Load regulation ∆VOLOAD VIN = 15V, IO = 0.5 to 1.5A ∆VO/∆Ta Output voltage temperature ±0.5 Designed target value. * mV mV/°C coefficient Ripple attenuation factor RREJ f = 100 to 120Hz Output leak current IOleak VIN = 15V, SWOUT = -0.4V Current limiter operating voltage IS Operating current 45 VIN = 15V IVIN dB µA 50 3.1 A VIN = 15V 5.6 mA VIN = 15V, ENA = 5V 200 µA 0.6 V Standby current ISTBY ENA pin LOW voltage range VENAL ENA pin HIGH voltage range VENAH Thermal shutdown operating TSD Designed target value. * 165 °C ∆TSD Designed target value. * 15 °C 2.4 VIN V temperature Thermal shutdown Hysteresis width * Design target value: No measurement made. Package Dimensions unit : mm (typ) 3079A Pd max -- Ta 4.5 2.7 10.4max 10.0 2.7 0.9 5 1 0.8 (1.6) 17.8 21.3 23.0 15.0 1.3 (8.8) 3.6 Allowable pwer dissipation, Pd max -- W 10.0 1.7 0.45 4.5 8.0 7.5 100×100×1.5mm3 6.0 5.6 50×50×1.5mm3 4.0 3.3 2.0 1.75 Al heat sink plate tightening torque 39N.cm With silicone grease applied. 30×30×1.5mm3 No heat sink 0 --30 8.4 Infinitely large heat sink θjc=5°C/W 0 20 40 60 80 100 120 Ambient temperature, Ta -- °C 140 160 PCA00833 SANYO : TO-220-5H Pin Assignment (1) VIN (2) SWOUT (3) GND (4) VOS (5) ENA No.A0476-2/4 LA5779 Block Diagram VIN 1 2 SWOUT Reg. OCP Reset OSC Drive Comp. THD 4 VOS Amp. VREF 5 3 ENA GND Application Circuit Example L1 47µH VIN SWOUT LA5779 C2 390µF D1 SBD C1 470µF /50V VOS ENA GND R2 R1 No.A0476-3/4 LA5779 Description of Functional Settings Calculation equation to set the output voltage This IC controls the switching output so that the VOS pin voltage becomes 1.23V (typ). The equation to set the output voltage is as follows: R2 VO = 1+ × 1.23V(typ) R1 The VOS pin has the inrush current of 1µA (typ). Therefore, the error becomes larger when R1 and R2 resistance values are large. SANYO Semiconductor Co.,Ltd. assumes no responsibility for equipment failures that result from using products at values that exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or other parameters) listed in products specifications of any and all SANYO Semiconductor Co.,Ltd. products described or contained herein. SANYO Semiconductor Co.,Ltd. strives to supply high-quality high-reliability products, however, any and all semiconductor products fail or malfunction with some probability. It is possible that these probabilistic failures or malfunction could give rise to accidents or events that could endanger human lives, trouble that could give rise to smoke or fire, or accidents that could cause damage to other property. When designing equipment, adopt safety measures so that these kinds of accidents or events cannot occur. Such measures include but are not limited to protective circuits and error prevention circuits for safe design, redundant design, and structural design. In the event that any or all SANYO Semiconductor Co.,Ltd. products described or contained herein are controlled under any of applicable local export control laws and regulations, such products may require the export license from the authorities concerned in accordance with the above law. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying and recording, or any information storage or retrieval system, or otherwise, without the prior written consent of SANYO Semiconductor Co.,Ltd. Any and all information described or contained herein are subject to change without notice due to product/technology improvement, etc. When designing equipment, refer to the "Delivery Specification" for the SANYO Semiconductor Co.,Ltd. product that you intend to use. Information (including circuit diagrams and circuit parameters) herein is for example only; it is not guaranteed for volume production. Upon using the technical information or products described herein, neither warranty nor license shall be granted with regard to intellectual property rights or any other rights of SANYO Semiconductor Co.,Ltd. or any third party. SANYO Semiconductor Co.,Ltd. shall not be liable for any claim or suits with regard to a third party's intellctual property rights which has resulted from the use of the technical information and products mentioned above. This catalog provides information as of June, 2007. Specifications and information herein are subject to change without notice. PS No.A0476-4/4