View 1584_963119.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

Ordering number : EN3660B
Monolithic Linear IC
LA5677M
Dual Switching Regulator Control IC
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.
Package Dimensions
unit: mm 3035A-MFP16
[LA5677M]
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
Specifications
Maximum Ratings at Ta = 25C
Parameter Maximum supply voltage Error amplifier input voltage Collector output voltage Collector output current Allowable power dissipation Operating temperature Storage temperature Symbol VCC max VI VO IO Pd max Topr Tstg Conditions
SANYO: MFP16
Ratings 20 20 20 21 330 -20 to +85 -40 to +125
Unit V V V mA mW C C
Operating Conditions at Ta = 25C
Ratings Parameter Recommended supply voltage Error amplifier input voltage Collector output voltage Collector output current Feedback pin current Feedback resistance Timing capacitance Timing resistance Oscillator frequency Symbol VCC VI VO IO IFT RNF CT RT fOSC 100 150 5.1 1 15000 100 500 Conditions min 3.6 1.05 -0.3 typ max 18 1.45 +18 20 45 Unit V V V mA A k pF k kHz
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's 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.
SANYO Electric Co.,Ltd. Semiconductor Bussiness Headquarters
TOKYO OFFICE Tokyo Bldg., 1-10, 1 Chome, Ueno, Taito-ku, TOKYO, 110-8534 JAPAN
O3098HA (OT)/92793TS A8-8023 No. 3660-1/7
LA5677M
Ratings Parameter Output voltage Line regulation Load regulation Reference voltage block Output voltage temperature variation Short circuit output current High level threshold voltage Low input malfunction Low level threshold prevention block voltage Hysteresis Reset voltage Input threshold voltage Input standby voltage Input latch voltage Input source current Comparator threshold voltage Oscillator frequency fosc standard deviation Oscillator block Frequency variation 1 (VCC) Frequency variation 2 (Ta) Input bias current Latch mode source current Idle period adjustment circuit block Latch input voltage Input threshold voltage IOSC VtH VtL Vhys Vr Vtpc Vstby V1 Ibpc Vtc fosc fA fV ft Ibdt Idt Vdt Vt0 Vt100 Iodt = 40 A With a duty cycle of 0% fosc = 10 kHz, With a duty cycle of 100% 1.20 2.3 2.05 1.45 2.25 230 No pull-up No pull-up When VS.C.P is 1.0 V Pins 5, 12 Ct = 330 pF, Rt = 10 k All values agree VCC = 3.6 to 18 V 12 Vref = 0 V IOR = 0.1 mA IOR = 0.1 mA IOR = 0.1 mA IOR = 0.1 mA 80 1.5 1.02 3 Symbol Vref Vline Vload IOR = 1 mA VCC = 3.6 to 18 V IOR = 0.1 to 1 mA Conditions min 2.40 typ 2.50 2 1 0.2 max 2.60 10 7.5 Unit V mV mV %
10 2.70 2.58 120 1.9 1.16 0.78 0.74 18 1.2 200 10 1 0.4
30
mA V V mV V
1.30
V V V
Protection circuit block
27
A V kHz % % %
1
A A V V V
Continued on next page. No. 3660-2/7
LA5677M
Continued from preceding page.
Ratings Parameter Input offset voltage Input offset current Input bias current Common mode input voltage range Open loop gain Unity gain bandwidth Error amplifier block Common mode rejection ratio Maximum output voltage amplitude (1) Maximum output voltage amplitude (2) Output sink current (pins 5, 12) Output source current (pins 5, 12) Output leakage current Output block Output saturation voltage Short circuit output current Input threshold voltage PWM comparator block Input sink current (pins 5, 12) Input source current (pins 5, 12) Standby current Whole device Average supply current ICC1 ICC2 Symbol VIO IIO IB VICR AV GB CMRR VO + m VO - m IO + m IO - m Ileak Vsat IOS Vt0 Vt100 VID = -0.1 V, VO = 1.25 V VID = 0.1 V, VO = 1.25 V VO = 18 V IO = 10 mA VO = 6 V With a duty cycle of 0% fosc = 10 kHz, With a duty cycle of 100% With V (pins 5, 12) = 1.25 V With V (pins 5, 12) = 1.25 V Output off state RT = 10 k 1.20 1.0 60 2.05 1.45 1.6 -70 1.6 1.9 2.2 2.6 2.25 1.6 -70 10 2 Vref - 0.1 1.0 Conditions With V (pins 5, 12) = 1.25 V With V (pins 5, 12) = 1.25 V With V (pins 5, 12) = 1.25 V VCC = 3.6 to 18 V RNF = 200 k 1.05 80 1.5 80 min -6 -100 160 typ max +6 +100 500 1.45 Unit mV nA nA V dB MHz dB V V mA A A V mA V V mA A mA mA
Pin Functions
No. 1 2 3 4 5 6 7 8 CT RT OP1+ OP1- OP1OUT DEAD TIME1 OUT1 GND Pin Function Triangle wave oscillator capacitor connection Triangle wave oscillator resistor connection Error amplifier 1 + input Error amplifier 1 - input Error amplifier 1 output Dead time 1 control Output 1 Ground connection No. 9 10 11 12 13 14 15 16 VCC OUT2 DEAD TIME2 OP2OUT OP2- OP2+ S. C. P Vref Pin Power supply input Output 2 Dead time 2 control Error amplifier 2 output Error amplifier 2 - input Error amplifier 2 + input Short circuit protection circuit connection Reference voltage (2.5 V) Function
No. 3660-3/7
LA5677M
Equivalent Circuit Block Diagram
Operation Overview
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's 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's 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). VPE1 = Vref {1 - exp (-t1/R41*CPT)} VPE2 = Vref {1 - exp (-t2/R41*CPT)} 0.75 = 2.5 {1 - exp (-t1/80 k*CPT)} 1.20 = 2.5 {1 - exp (-t2/80 k*CPT)} t1 = 28.56 k*CPT t2 = 52.31 k*CPT tPT = t2 - t1 = 23.75 k*CPT CPT = 42.1 x tPT [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 CT pin (pin 1) and the RT 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 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 Circuit: +5 V, 1 A step-down converter and -5 V, 0.5 A polarity inverting converter using a
12 V input
No. 3660-6/7
LA5677M
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'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. 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 "Delivery 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.
This catalog provides information as of December, 1998. Specifications and information herein are subject to change without notice. PS No. 3660-7/7

▲Up To Search▲

Price & Availability of 1584

	To Download 1584 Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .