ordering number : en3660b o3098ha (ot)/92793ts a8-8023 no. 3660-1/7 LA5677M sanyo electric co.,ltd. semiconductor bussiness headquarters tokyo office tokyo bldg., 1-10, 1 chome, ueno, taito-ku, tokyo, 110-8534 japan dual switching regulator control ic monolithic linear ic any and all sanyo products described or contained herein do not have specifications that can handle applications that require extremely high levels of reliability, such as life-support systems, aircraft? control systems, or other applications whose failure can be reasonably expected to result in serious physical and/or material damage. consult with your sanyo representative nearest you before using any sanyo products described or contained herein in such applications. sanyo 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 products described or contained herein. overview the LA5677M supports single-input control of the outputs of two converters of arbitrary types, including step up, step down and inverting. since the LA5677M supports low voltage (3.6 to 18 v) and high frequency (1 to 500 khz) operation, it is ideal for use in power supplies in battery powered portable equipment. features operates at low voltages (3.6 to 18 v) can be used with high frequency oscillators (1 to 500 khz) built-in low input malfunction prevention circuit built-in timer-latch short circuit protection circuit package dimensions unit: mm 3035a-mfp16 specifications maximum ratings at ta = 25? parameter symbol conditions ratings unit maximum supply voltage v cc max 20 v error amplifier input voltage v i 20 v collector output voltage v o 20 v collector output current i o 21 ma allowable power dissipation pd max 330 mw operating temperature topr ?0 to +85 ? storage temperature tstg ?0 to +125 ? parameter symbol conditions ratings unit min typ max recommended supply voltage v cc 3.6 18 v error amplifier input voltage v i 1.05 1.45 v collector output voltage v o ?.3 +18 v collector output current i o 20 ma feedback pin current i ft 45 ? feedback resistance r nf 100 k timing capacitance c t 150 15000 pf timing resistance r t 5.1 100 k oscillator frequency f osc 1 500 khz sanyo: mfp16 [LA5677M] operating conditions at ta = 25?
no. 3660- 2 /7 LA5677M parameter symbol conditions ratings unit min typ max output voltage vref i or = 1 ma 2.40 2.50 2.60 v line regulation v line v cc = 3.6 to 18 v 2 10 mv load regulation v load i or = 0.1 to 1 ma 1 7.5 mv reference voltage output voltage block temperature 0.2 % variation short circuit output i osc vref = 0 v 3 10 30 ma current high level threshold v th i or = 0.1 ma 2.70 v voltage low input malfunction low level threshold v tl i or = 0.1 ma 2.58 v prevention block voltage hysteresis vhys i or = 0.1 ma 80 120 mv reset voltage vr i or = 0.1 ma 1.5 1.9 v input threshold vtpc 1.02 1.16 1.30 v voltage input standby vstby no pull-up 0.78 v protection circuit voltage block input latch voltage v 1 no pull-up 0.74 v input source current ibpc when vs.c.p is 1.0 v 12 18 27 a comparator vtc pins 5, 12 1.2 v threshold voltage oscillator frequency fosc ct = 330 pf, rt = 10 k 200 khz fosc standard ? f a all values agree 10 % deviation oscillator block frequency variation ? f v v cc = 3.6 to 18 v 1 % 1 (v cc ) frequency variation ? ft 0.4 % 2 (ta) input bias current ibdt 1 a latch mode source idt 230 a current idle period latch input voltage vdt iodt = 40 a 2.3 v adjustment circuit vt0 with a duty cycle of 0% 2.05 2.25 v block input threshold voltage vt100 fosc = 10 khz, 1.20 1.45 v with a duty cycle of 100% continued on next page.
continued from preceding page. pin functions no. 3660- 3 /7 LA5677M parameter symbol conditions ratings unit min typ max input offset voltage v io with v (pins 5, 12) = 1.25 v ? +6 mv input offset current i io with v (pins 5, 12) = 1.25 v ?00 +100 na input bias current i b with v (pins 5, 12) = 1.25 v 160 500 na common mode v icr v cc = 3.6 to 18 v 1.05 1.45 v input voltage range open loop gain a v r nf = 200 k 80 db unity gain g b 1.5 mhz bandwidth error amplifier block common mode cmrr 80 db rejection ratio maximum output v o + m vref ?0.1 v voltage amplitude (1) maximum output v o ?m 1.0 v voltage amplitude (2) output sink current i o + m v id = ?.1 v, v o = 1.25 v 1.6 ma (pins 5, 12) output source i o ?m v id = 0.1 v, v o = 1.25 v ?0 a current (pins 5, 12) output leakage i leak v o = 18 v 10 a current output block output saturation vsat i o = 10 ma 1.0 2 v voltage short circuit output i os v o = 6 v 60 ma current vt0 with a duty cycle of 0% 2.05 2.25 v input threshold voltage vt100 fosc = 10 khz, 1.20 1.45 v pwm comparator with a duty cycle of 100% block input sink current with v (pins 5, 12) = 1.25 v 1.6 ma (pins 5, 12) input source current with v (pins 5, 12) = 1.25 v ?0 a (pins 5, 12) standby current i cc 1 output off state 1.6 2.2 ma whole device average supply i cc 2 r t = 10 k 1.9 2.6 ma current no. pin function no. pin function 1 c t triangle wave oscillator capacitor connection 9 v cc power supply input 2 r t triangle wave oscillator resistor connection 10 out2 output 2 3 op1+ error amplifier 1 + input 11 dead time2 dead time 2 control 4 op1 error amplifier 1 ?input 12 op2 out error amplifier 2 output 5 op1 out error amplifier 1 output 13 op2 error amplifier 2 ?input 6 dead time1 dead time 1 control 14 op2+ error amplifier 2 + input 7 out1 output 1 15 s. c. p short circuit protection circuit connection 8 gnd ground connection 16 vref reference voltage (2.5 v)
equiv alent cir cuit bloc k dia gram operation over vie w 1. reference voltage block the reference voltage block uses a 2.5 v reference voltage. this voltage is made available to external circuits from pin 16, and at the same time is used as the reference power supply by internal circuits. 2. low input malfunction prevention circuit block the low input malfunction prevention circuit prevents incorrect operation when the power supply is brought up or during brief voltage drops. after power is applied and the reference voltage reaches vbe, the output transistors are held off until the power supply voltage becomes 2.72 v (typical). the dead time control pin voltage is held at the high level (vref) and the short circuit protection pin is held low (the initial state). since this circuit has a hysteresis of 120 mv (typical) chattering due to power supply ripple can be prevented to a certain extent. 3. timer-latch short circuit protection circuit during output overload, the timer-latch short circuit protection circuit? short circuit protection comparator turns off q86 when the error amplifier inputs a low level signal (a voltage less than vref/2) to one or both of the short circuit protection comparator? two non-inverting inputs. at this time the pin 15 voltage increases from about 0.75 v (steady state) towards vref as the external capacitor is charged from vref through resistor r41 (80 k ). when the capacitor is charged to about 1.2 v, the protection latch is set, the output transistors are turned off, and the idle time becomes 100%. this also turns on q97 which resets the protection enable state. the latch circuit reset voltage is under 1.9 v (typical). v pe 1 = vref {1 ?exp (?1/r41? pt )} v pe 2 = vref {1 ?exp (?2/r41? pt )} 0.75 = 2.5 {1 ?exp (?1/80 k? pt )} 1.20 = 2.5 {1 ?exp (?2/80 k? pt )} t1 = 28.56 k? pt t2 = 52.31 k? pt t pt = t2 ?t1 = 23.75 k? pt c pt = 42.1 t pt [ f] no. 3660- 4 /7 LA5677M
figure 1 timer-latch short circuit protection circuit figure 2 timing resistance/oscillator frequency characteristics 4. triangle wave oscillator block the triangle wave oscillator generates an essentially symmetric triangle wave using a timing capacitor and resistor attached to the c t pin (pin 1) and the r t pin (pin 2), respectively. the voltage amplitude is between 1.4 and 2.0 v with pin 2 stabilized at 1 v. the oscillator frequency is determined by the external capacitor and resistor. 5. idle period adjustment circuit block the idle period adjustment circuit consists of pwm comparators 1 and 2, each of which has one non-inverting and two inverting inputs. the output pulse width (on time) is controlled according to the input voltage. pins 6 and 11 are dead time control pins, and are used to limit the maximum value of the pulse width. a pin voltage of 2.05 v (typical) or over results in the output being off for the whole period, and a pin voltage of 1.45 v (typical) or lower results in the output being on for the whole period. no. 3660- 5 /7 LA5677M
no. 3660- 6 /7 LA5677M 6. error amplifier block error amplifiers 1 and 2 are amplifiers for detecting the output voltages, i.e., the LA5677M application system output voltages. since the common mode input voltage range is 1.05 to 1.45 v, we recommend setting their input voltages to vref/2. pins 5 and 12 are the output pins, and the gain is set and the frequency characteristics adjusted with a resistor and a capacitor connected between the outputs and the non-inverting inputs of each amplifier. the outputs are also connected to the short circuit protection circuit detection circuit. 7. output block the outputs are single end open collector outputs with an npn darlington pair structure. sample application cir cuit: +5 v, 1 a step-down converter and ? v, 0.5 a polarity inverting converter using a 12 v input
ps no. 3660- 7 /7 LA5677M this catalog provides information as of december, 1998. specifications and information herein are subject to change without notice. specifications of any and all sanyo 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? 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? products or equipment. sanyo electric co., ltd. strives to supply high-quality high-reliability products. however, any and all semiconductor products fail with some probability. it is possible that these probabilistic failures could give rise to accidents or events that could endanger human lives, that could give rise to smoke or fire, or 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 products (including technical data, services) described or contained herein are controlled under any of applicable local export control laws and regulations, such products must not be exported without obtaining 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 permission of sanyo electric 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 ?elivery specification for the sanyo 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. sanyo believes information herein is accurate and reliable, but no guarantees are made or implied regarding its use or any infringements of intellectual property rights or other rights of third parties.
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