SC2618 Semtech, SC2618 Datasheet

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SC2618

Manufacturer Part Number
SC2618
Description
Miniature PWM Controller for Buck Regulator
Manufacturer
Semtech
Datasheet
The SC2618 is a hysteretic mode PWM controller de-
signed for high efficiency, low cost “Point of Load” appli-
cations.
The hysteretic control scheme allows the use of ceramic
output capacitors without the need for compensation
components and difficult calculations.
An internal soft start prevents output voltage from start
up overshoot. A “Hiccup” short circuit protection provides
protection against output short circuits as well as ad-
verse input supply sequencing.
POWER MANAGEMENT
Description
Revision: September 19, 2005
Typical Application Circuit
VIN
BOOST
VCC
GND
5
3
2
BST
VCC
GND
SC2618
DH
DL
FB
6
1
4
1
Features
Applications
Q1
Q2
Operating Frequency up to 500kHz
Input supply from 5V to 12V
0.5A gate drive capability
Internal soft start
Internal, trimmed bandgap reference (
Hiccup mode short circuit protection
Input supply sequence protection
6 lead SOT23 package
Graphics IC Power supplies
Embedded, low cost, high efficiency converters
Miniature PWM Controller
for Buck Regulator
www.DataSheet4U.com
VO
GND
www.semtech.com
SC2618
±1%)

Related parts for SC2618

SC2618 Summary of contents

Page 1

... POWER MANAGEMENT Description The SC2618 is a hysteretic mode PWM controller de- signed for high efficiency, low cost “Point of Load” appli- cations. The hysteretic control scheme allows the use of ceramic output capacitors without the need for compensation components and difficult calculations. An internal soft start prevents output voltage from start up overshoot. A “ ...

Page 2

... SC2618 ° C ° C ° C ° C ° ° ...

Page 3

... FB  2004 Semtech Corp. Ordering Information Notes: BST (1) Only available in tape and reel packaging. A reel contains 3000 devices. FB (2) SC2618SKTRT is the lead free version. This product is fully WEEE and RoHS compliant ...

Page 4

... POWER MANAGEMENT Theory of Operation The SC2618 is a hysteretic mode PWM controller. It uses a comparator to generate PWM wave with minimum on time and off time control. As shown in the block diagram, the output voltage is fed back to the comparator nega- tive input and compared to a setting voltage. If the out- ...

Page 5

... Fig. 3. Soft start, inductor current and overshoot Normally, controllers with an external soft start capaci- tor, have soft start set so long that overshoot is unde- tectable. Since the soft start for the SC2618 is internal necessarily limited and the maximum values of L and Co should meet the constraints of: ⋅ ...

Page 6

... Bootstrap Circuit Bootstrap Circuit Bootstrap Circuit Bootstrap Circuit The SC2618 uses an external bootstrap circuit to pro- vide a voltage at BST pin for the top MOSFET drive. This voltage is held bootstrap capacitor. Typically recommended to use a 1uF ceramic capacitor with 25V rating and a commonly available diode IN4148 for the bootstrap circuit ...

Page 7

... POWER MANAGEMENT Layout Guidelines Careful attention to layout requirements are necessary for successful implementation of the SC2618 controller. High currents switching 500kHz are present in the application and their effect on ground plane voltage differentials must be understood and minimized. 1). The high power parts of the circuit should be laid out first ...

Page 8

... POWER MANAGEMENT Layout Guidelines (Cont.)  2004 Semtech Corp. Currents in Power Section Vin + + 8 SC2618 www.DataSheet4U.com Vout www.semtech.com ...

Page 9

... .055 .037 X X .024 Y .043 .141 Semtech Corporation Power Management Products Division 200 Flynn Road, Camarillo, CA 93012 Phone: (805)498-2111 FAX (805)498-3804 9 SC2618 www.DataSheet4U.com DIMENSIONS INCHES MILLIMETERS NOM MAX MIN NOM MAX - .057 - 1.45 0. .006 0.00 0.15 .045 .051 .90 1.15 1. .020 ...

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