POWER MANAGEMENT
1
www.semtech.com
SC4501
2Amp, 2MHz Step-Up Switching
Regulator with Soft-Start
Description
Features
Applications
Flat screen LCD bias supplies
TFT bias supplies
XDSL power supplies
Medical equipments
Digital video cameras
Portables devices
White LED power supplies
The SC4501 is a high-frequency current-mode step-up
switching regulator with an integrated 2A power transis-
tor. Its high switching frequency (programmable up to
2MHz) allows the use of tiny surface-mount external pas-
sive components. Programmable soft-start eliminates high
inrush current during start-up. The internal switch is rated
at 32V making the converter suitable for high voltage ap-
plications such as Boost, SEPIC and Flyback.
The operating frequency of the SC4501 can be set with an
external resistor. The ability to set the operating frequency
gives the SC4501 design flexibilities. A dedicated COMP
pin allows optimization of the loop response. The SC4501
is available in thermally enhanced 8-Pin MSOP and 10-pin
MLPD packages.
Typical Application Circuit
Low saturation voltage switch: 250mV at 2A
Constant switching frequency current-mode control
Programmable switching frequency up to 2MHz
Soft-Start function
Input voltage range from 1.4V to 16V
Output voltage up to 32V
Low shutdown current
Adjustable undervoltage lockout threshold
Small low-profile thermally enhanced packages
Revision: November 17, 2004
C1
2.2
F
5V
VIN
VOUT
SC4501
2
3
1
5
6
4
GND
SHDN
SS
IN
SW
FB
ROSC
COMP
8
7
ON
OFF
C3
10BQ015
R4
D1
L1
C2
10
F
47nF
R2
20K
R1
174K
12V, 0.7
C4
R3
C6
Figure 1(a). 5V to 12V Boost Converter.
All Capacitors are Ceramic.
MSOP-8 Pinout
f
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Figure 1(b). Efficiencies of 5V to 12V Boost Converters at
700KHz, 1.35MHz and 2MHz.
Efficiency
50
55
60
65
70
75
80
85
90
95
0
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
Load Current (A)
Efficiency (%)
V
OUT
= 12V
V
IN
= 5V
10.5
H, 700KHz
3.3
H, 2MHz
4.7
H, 1.35MHz
2
2004 Semtech Corp.
POWER MANAGEMENT
SC4501
www.semtech.com
Absolute Maximum Rating
Electrical Characteristics
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Unless specified: V
IN
= 2V, SHDN = 1.5V, R
OSC
= 7.68k
, -40C < T
A
= T
J
< 85C
Exceeding the specifications below may result in permanent damage to the device, or device malfunction. Operation outside of the parameters specified
in the Electrical Characteristics section is not implied. Exposure to Absolute Maximum rated conditions for extended periods of time may affect device
reliability.
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3
2004 Semtech Corp.
www.semtech.com
POWER MANAGEMENT
SC4501
Pin Configurations
Ordering Information
Electrical Characteristics (Cont.)
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TOP VIEW
(10 Pin - MLPD, 3 x 3mm)
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Notes:
(1) Only available in tape and reel packaging. A reel
contains 3000 devices for MLP package and 2500
devices for MSOP.
(2) Lead free product. This product is fully WEEE and
RoHS compliant.
(3) Contact factory for availability.
1
2
3
4
SS
COMP
TOP VIEW
(8 Pin MSOP-EDP)
5
6
7
8
ROSC
FB
IN
SHDN
SW
GND
Unless specified: V
IN
= 2V, SHDN = 1.5V, R
OSC
= 7.68k
, -40C < T
A
= T
J
< 85C
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