SC4503
SC4503 is 1.3MHz Step-Up Switching Regulator manufactured by SEMTECH.
Description
The SC4503 is a 1.3MHz current-mode step-up switching regulator with an integrated 1.4A power transistor. Its high switching frequency allows the use of tiny surface-mount external passive ponents. The SC4503 Features a bined shutdown and soft-start pin. The optional soft-start function eliminates high input current and output overshoot during start-up. The internal pensation network acmodates a wide range of voltage conversion ratios. The internal switch is rated at 34V .. making the device suitable for high voltage applications such as Boost and SEPIC. The SC4503 is available in low-profile 5-lead TSOT-23 and 8-lead 2X2mm MLPD-W packages. The SC4503’s low shutdown current (< 1μA), high frequency operation and small size make it suitable for portable applications.
Features
Low Saturation Voltage Switch: 260m V at 1.4A 1.3MHz Constant Switching Frequency Peak Current-mode Control Internal pensation Programmable Soft-Start Input Voltage Range From 2.5V to 20V Output Voltage up to 27V Uses Small Inductors and Ceramic Capacitors Low Shutdown Current (< 1μA) Low Profile 5-Lead TSOT-23 and 8-Lead 2X2mm
MLPD-W packages
Fully WEEE and Roh S pliant
Applications
Local DC-DC Converters TFT Bias Supplies XDSL Power Supplies Medical Equipment Digital Cameras Portable Devices White LED Drivers
Typical Typical Application Application Circuit Circuit
D1 10BQ015 1 SW SC4503 OFF ON 4 SHDN/SS GND 2 R2 49.9k FB 3 C4 15p F R1 432k C2 4.7µF
VIN 5V 5 IN C1 1µF
L1 4.7µH
VOUT 12V, 0.5A
Efficiency vs Load Current
95 90 85
Efficiency (%)
1.3MHz
80 75 70 65 60 55
VOUT = 12V
C1: Murata GRM188R61A105K C2: Murata GRM21BR61C475K L1: Sumida CDC5D23B-4R7 Figure 1(a). 5V to 12V Boost Converter
May 4, 2007 1
50 0.001
Load Current (A)
Figure 1(b). Efficiency of the 5V to 12V Boost Converter
.semtech.
POWER MANAGEMENT Absolute Maximum Ratings
Exceeding the specifications below may result in permanent damage to the...
