13107 ms im 20070112-s00004 no.a0663-1/7 LV5781 overview the LV5781 is a 1-channel chopper-type (low-side schottky di ode) step-down switching regulator. it incorporates an 80m ? (typical) power mosfet to achieve high-effi ciency operation for 3a output currents. the output voltage is set internally to 3.3v. by adding two external resistors, it is possible to set the voltage to any desired setting above 0.85v. inrush current at star tup can be prevented by the soft start function. using the on/off pins, the converter can be set to standby mode in which the current consumption is 10 a or less. both the load and the ic are protected by means of the overcurre nt and thermal protection functions. the converter uses the hssop14 miniature package. functions ? 3a, 1-channel chopper-type, step-down switching regulator ? output voltage: 3.3v ? setting of any output voltage enab led (external resistors required) ? high efficiency: 90% at i out =1a, v o =3.3v ? miniature pack age: hssop14 ? soft start function ? standby mode ? overcurrent protection ? thermal shutdown ? fixed frequency: 180khz applications ? lcd tvs ? game machines ordering number : ena0663a bi-cmos ic 3a, point-of-load, chopper-type step-down converter specifications of any and all sanyo semiconductor co.,l td. 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 ' sproductsor equipment. any and all sanyo semiconductor co.,ltd. products described or contained herein are, with regard to "standard application", intended for the use as general el ectronics equipment (home appliances, av equipment, communication device, office equipment, industrial equ ipment etc.). the products mentioned herein shall not be intended for use for any "special application" (medica l equipment whose purpose is to sustain life, aerospace instrument, nuclear control device, burning appliances, t ransportation machine, traffic signal system, safety equipment etc.) that shall require extremely high level of re liability and can directly threaten human lives in case of failure or malfunction of the product or may cause har m to human bodies, nor shall they grant any guarantee thereof. if you should intend to use our products for app lications 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 n o consultation or inquiry before the intended use, our customer shall be solely responsible for the use.
LV5781 no.a0663-2/7 specifications absolute maximum ratings at ta=25 c parameter symbol conditions ratings unit maximum input voltage v in max 6.5 v maximum cboot pin voltage vbt max 13 v maximum sw pin voltage vsw max 6.5 v maximum voltage between cboot and sw pins vbs max 6.5 v maximum voltage at fb, ss, and enable pins vfs max 6.5 v junction temperature tj max 125 c allowable power dissipation pd max mounted on a circuit board *1 0.85 w operating temperature range topr -30 to +80 c storage temperature range tstg -40 to +125 c *1: mounted on a specified board: 114.3mm 76.1mm 1.6mm, glass epoxy. *2: to ensure that the maximum voltage is not exceeded even for an instant, check that the coil voltage and other surge voltage levels are factored in. recommended operating conditions at ta=25 c parameter symbol conditions ratings unit v in pin voltage v in 4.5 to 6 v cboot pin voltage vbt 0 to 6 v sw pin voltage vsw 6v fb, ss, and enable pin voltage vfso 6v electrical characteristics at ta=25 c, v in =5v (unless specifically specified) ratings parameter symbol conditions min typ max unit output voltage 1 v out 1 fb2 pin selected 3.2 3.3 3.4 v output voltage 2 v out 2 dependent on the external voltage divider 0.85 v standby mode ic consumption current i cc 1 enable=0v 1 10 a operating time ic consumption current i cc 2 enable=3v 2 5 ma enable high level voltage venh 3 v enable low level voltage venl 0.7 v efficiency effcy i out =1a, v o =3.3v 90 % reference voltage vref v in =4.5v to 6v( 2%) 0.76 0.8 0.84 v fb pin bias current iref 50 200 na on resistance ron cboot=5v 80 m ? soft start current iss 3 6.5 13 a oscillation frequency fosc 145 180 225 khz maximum on duty ratio d max 85 % current limiting value icl 4.1 a under voltage detection vl 3.3 3.7 4.2 v under voltage detection hysteresis vlh 0.15 0.185 0.25 v thermal shutdown temperature ttsd design guarantee value* 180 c thermal shutdown temperature hysteresis dtsd design guarantee value* 20 c *these are design guarantee values and no measurements are made.
LV5781 no.a0663-3/7 package dimensions unit : mm (typ) 3313 block diagram and sample application circuits sanyo : hssop14(225mil) 6.5 6.4 4.4 0.22 0.65 1.3 (2.35) 1.5 17 8 14 0.1 1.5max (1.3) 0.5 0.15 error amp osc 180khz ss fb_gnd v in 6.5 ambient temperature, ta - c allowable power dissipation, pd max - w pd max -- ta mounted on a specified board: 114.3mm 76.1mm 1.6mm, glass epoxy
LV5781 no.a0663-4/7 pin assignment and sample application circuits sample application circuit 1 sample application circuit 2 *the capacitor between the fb0 and v out pins and capacitor between the oerramp pin and gnd (the capacitors shown inside the broken lines in the diagram) are used fo r phase compensation. their capacitance is intended to stop oscillation when oscillation is caused by the status of the output capacitor. as such, they can be left open under normal circumstances. 1 2 10 3 4 5 6 7 8 9 enable ss fb1 v in sw pgnd fb_gnd 11 13 12 14 v in sw v in cboot oerramp fb2 fb0 g n d on off 3.3v g n d 1 2 10 3 4 5 6 7 8 9 enable ss fb1 v in sw pgnd fb_gnd 11 13 12 14 v in sw v in cboot oerramp fb2 fb0 g n d on off v out g n d
LV5781 no.a0663-5/7 pin functions pin no. pin name description 1 fb_gnd gnd of output voltage setting pins fb0 and fb2. it is connected to gnd for use when pin fb2 is used. 2 enable output on/off with an active-high polarity. when set to l, the current consumption is reduced to 10 a or less. 3 ss soft start time constant setting. the charge current is set to approx. 6.5 a and when a capacitor of 0.1 f is connected between this pin and gnd, the output rises in approx. 12ms. 4 fb1 test pin for verifying the internal referenc e voltage. it must be set to open for actual use. 5, 8, 10 v in power input. it is used with vo ltages ranging from 4.5v to 6v. 6, 9 sw inductor drive output 7 pgnd power gnd pin. this is the output gnd. it is connected so that where at al l possible, no impedance is shared with other gnd pins (gnd, fb_gnd). 11 cboot for generating the gate voltage of the internal hi gh-side n-channel mos transistor. a capacitor with a capacitance of at least 0.1 f (max. 2.2 f) is connected between this pin and the sw pin for use. 12 oerramp transconductance-type error_amp output. an integr ation constant is provided between this pin and gnd to implement phase compensation. 13 fb2 used to feed back the output volt age to this pin when the output voltage is to be set to 3.3v. in such a case, fb_gnd is connected to gnd. refer to application circuit 1. 14 fb0 when the output voltage is to be set to a desired value, connect resistors between fb0 and gnd and between fb0 and v out to feed back the output voltage to this pin. in such a case, leave fb_gnd and fb2 open. refer to application circuit 2. heat sink fin gnd analog gnd (connected to gnd). input equivalent circuits pin no. pin name equivalent circuit 5, 8, 10 gnd v in 1 4 13 14 fb_gnd fb1 fb2 fb0 continued on next page fb_gnd v in gnd fb1 fb0 fb2 54.5k ? 118k ? 50k ? 116k ? v in gnd
LV5781 no.a0663-6/7 continued from preceding page pin no. pin name equivalent circuit 2 enable 3 ss 6, 9 7 11 sw pgnd cboot 12 oerramp enable 55k ? gnd 100k ? v in v in gnd fb0 ss vref 97k ? 300 ? 100 ? 300 ? 6.5 ?
LV5781 no.a0663-7/7 ps this catalog provides informati on as january, 2007. specifications and information herein are subject to change without notice. sanyo semiconductor co.,ltd. assumes no responsibility for equipment failures that result from using products at values that exceed, even momentarily, rate d values (such as maximum ratings, operating condition ranges, or other parameters) listed in products specif ications of any and all sanyo semiconductor co.,ltd. products described or contained herein. sanyo semiconductor co.,ltd. strives to supply high-qu ality high-reliability pr oducts, however, any and all semiconductor products fail or malfunction with some proba bility. 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 damag e 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. upon using the technical information or products descr ibed 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. information (including circuit diagrams and circuit par ameters) herein is for example only; it is not guaranteed for volume production. 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. 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 l aws 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.
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