SC4524DSETRT

Manufacturer Part NumberSC4524DSETRT
DescriptionIC, DC-DC CONV, 2MHz, 8-SOIC
ManufacturerSemtech
Series-
TypeStep-Down (Buck), PWM - Current Mode
SC4524DSETRT datasheets
 


Specifications of SC4524DSETRT

Primary Input Voltage30VNo. Of Outputs1
Output Voltage30VOutput Current2A
No. Of Pins8Operating Temperature Range-40°C To +85°C
Switching Frequency Max2MHzPackage / Case8-SOIC
Rohs CompliantYesInternal Switch(s)Yes
Synchronous RectifierNoNumber Of Outputs1
Voltage - Output1 V ~ 17.28 VCurrent - Output2A
Frequency - Switching300kHz ~ 1.3MHzVoltage - Input3 V ~ 18 V
Operating Temperature-40°C ~ 105°CMounting TypeSurface Mount
Lead Free Status / RoHS StatusLead free / RoHS Compliant  
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POWER MANAGEMENT
Description
The SC4524 is an adjustable frequency peak current-
mode step-down switching regulator with an integrated
2.3A, 30V switch. The SC4524 can be programmed up
to 1.5MHz. This allows the use of small inductor and
ceramic capacitors, resulting in very compact power
supplies. The SC4524 is suitable for next generation XDSL
modems, set-top boxes and point of load applications.
The SC4524 uses peak current-mode PWM control for
ease of compensation. Cycle-by-cycle current limit and
hiccup overload protection reduce power dissipation
during overload. Combined soft start and enable pin not
only eliminates output start up overshoot but also allows
power sequencing.
The SC4524 is available in SOIC-8 EDP package.
Typical Application Circuit
V IN
24V
IN
SS
BST
C7
22nF
SC4524
SW
FB
COMP
ROSC
GND
R5
15.4k
C6
22pF
10mF
R3
C5
17.4k
470pF
L1: Coiltronics FP3-4R7
C1: Murata GRM21BR60J226M
C3: Murata GRM32ER71H106K
Figure 1. 1MHz 24V to 5V/2A Step-down Converter.
Revision: December 30th, 2006
Programmable Frequency, 2A Output
30V Step-Down Switching Regulator
Features
u
Up to 1.5 MHz Programmable Switching Frequency
u
2.3A Integrated Switch
u
Wide Input Voltage Range 2.8V to 30V
u
Peak Current-Mode Control with Cycle-by-Cycle
Current Limiting
u
Hiccup Overload Protection
u
Soft-Start and Enable
u
Thermal Shutdown
u
Thermally Enhanced 8-Pin SOIC Package
u
Fully WEEE and RoHS Compliant
Applications
u
XDSL and Cable Modems
u
Set-top Boxes
u
Point of Load Applications
u
CPE Equipment
u
DSP Power Supplies
u
Disk Drives
D1
C2
1N4148
0.1mF
L1
OUT
4.7mH
5V/2A
R1
22.1k
D2
C3
C1
R2
20BQ030
5.49k
22mF
1
SC4524
Efficiency
90
85
80
75
70
65
60
55
50
0.0
0.5
1.0
1.5
Load Current (A)
www.semtech.com
2.0

SC4524DSETRT Summary of contents

  • Page 1

    ... Fully WEEE and RoHS Compliant Applications u XDSL and Cable Modems u Set-top Boxes u Point of Load Applications u CPE Equipment u DSP Power Supplies u Disk Drives D1 C2 1N4148 0.1mF L1 OUT 4.7mH 5V/2A R1 22. 20BQ030 5.49k 22mF 1 SC4524 Efficiency 0.0 0.5 1.0 1.5 Load Current (A) www.semtech.com 2.0 ...

  • Page 2

    ... Electrical Characteristics section is not implied < Notes: This device is ESD sensitive. ESD handling precaution is required. Electrical Characteristics Unless specified: -40°C < T < 85°C, -40°C < 2006 Semtech Corp < 105° 12. 5V OSC IN BST SC4524 www.semtech.com ° C ° ° ° C ° C ° µ µ ...

  • Page 3

    ... Notes: (1) Guaranteed by design, not tested in production. (2) The maximum duty cycle specified corresponds to 1.4MHz switching frequency. Duty cycles higher than those specified can be achieved by lowering the operating frequency. 2006 Semtech Corp. < 105° 12. 5V OSC IN BST SC4524 µ µ µ µ µ ...

  • Page 4

    ... Pin SOIC -EDP) Underside metal must be soldered to ground. Pin Descriptions 2006 Semtech Corp. Ordering Information BST S FB COMP Notes: SS (1) Only available in tape and reel packaging. A reel contains 2500 devices. (2) Lead free product. This product is fully WEEE and RoHS compliant ...

  • Page 5

    ... POWER MANAGEMENT Block Diagrams COMP ROSC 0.7V 0. FAULT FAULT Figure 3. Details of the Soft-Start and Overload Hiccup Control Circuit 2006 Semtech Corp SLOPE COMP + S PWM 0.7V REFERENCE FAULT & THERMA L SHUTDOW N SLO PE COMP SLOPE COMP CLK OSCILLATOR Figure 2. SC4524 Functional Diagram + + - - 1 ...

  • Page 6

    Ur € ƒr …h ‡ˆ…r Ã8             Ur €ƒr…h‡ˆ…rÃ8    6 à ‡  v € à G ‡  r  … ...

  • Page 7

    &    ã # "         $ U Ã2Ã!$ƒ ...

  • Page 8

    W ã ...

  • Page 9

    287 = 287 = = 287  = W ¼ ¼ ¼ ÔÏ D 287 = 287 ã ...

  • Page 10

     .+] ...

  • Page 11

    ¼ ...

  • Page 12

    D BST + 6: & %67 = & %   % 5(&7 b         ...

  • Page 13

    ... V BST IN OUT BST VIN IN SW SC4524 GND (a) DBST DZ MAX V BST + VZ - BST VIN SW IN SC4524 GND (c) 2006 Semtech Corp OUT » loss Since V OUT >2.5V) to maximize efficiency. In general efficiency T ON penalty increases as D decreases. . The energy loss b Figure 7 summarizes various ways of bootstrapping the ...

  • Page 14

    ... Load Current (mA) (a) Figure 8. Minimum Input Voltage Required to Start and to Maintain Bootstrap.(T 2006 Semtech Corp. 5V and a 3.3V converters on the load current. Once started the bootstrap circuit is able to sustain itself down to zero load. Shutdown and Soft-Start will BST T Pulling the soft-start pin below 0.8V with an open- collector NPN or an open-drain NMOS transistor turns off the regulator. In “ ...

  • Page 15

    ... Figure 9(b). Start-up Fails due to (i) Short Soft-start Duration or (ii) Output Overload or (iii) Output Short-circuited. 2006 Semtech Corp. Overload / Short-Circuit Protection The current limit comparator in the SC4524 limits the peak inductor current to 3.2A (typical). The regulator output voltage will fall if the load is increased above the current limit ...

  • Page 16

    W 287 w   287  287  Î Ë Û Ì Ì Ü Ü = Ï ÔÏ Í Ý Ð 287    ...

  • Page 17

    ... Figure 10. Simplified Control Loop Equivalent Circuit Gain OUT Figure 11. Bode Plots of Control-to-Ouput, Output-to-Control and the Overall Loop Gain. Control-to-output transfer function is shown with two poles near half the switching frequency 2006 Semtech Corp. POWER STAGE -1 GMP = 8 C11 GMA = -1 280 + 1.6M VOLTAGE C5 REFERENCE OUT ...

  • Page 18

    S 5 & & ¼ & ...

  • Page 19

    N Û ™  ¼ Ì Ü Ì Ü ¼  ¼  ¼  Í Ý ...

  • Page 20

    G‚h qÃ8uh …h p‡r …v†‡vp G‚h qÃ8uh …h p‡r …v†‡ ...

  • Page 21

    ... CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES). 2. DATUMS 3. DIMENSIONS "E1" AND "D" DO NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS. 4. REFERENCE JEDEC STD MS-012, VARIATION BA. Land Pattern - SOIC-8 EDP THERMAL VIA Ø 0.36mm Contact Information 2006 Semtech Corp DIM MIN A .053 2X E/2 A1 .000 A2 ...