SC4501 Datasheet | SEMTECH

Description The SC4501 is a high-frequency current-mode step-up switching regulator with an integrated 2A power transistor. Its high switching frequency (programmable up to 2MHz) allows the use of tiny surface-mount external passive ponents. Programmable soft-start eliminates high inrush current during start-up. The internal switch is rated at 32V making the converter suitable for high voltage applications such as Boost, SEPIC and Flyback. .. Features u u u u u u u u u Low saturation voltage switch: 220m V 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 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 P pin allows optimization of the loop response. The SC4501 is available in thermally enhanced 8-Pin MSOP and 10-pin MLPD packages. Applications u u u u u u u Flat screen LCD bias supplies TFT bias supplies XDSL power supplies Medical equipment Digital video cameras Portables devices White LED power supplies Typical Application Circuit VIN 5V 6 OFF ON 3 C1 2.2 µF 8 IN SHDN SC4501 SS GND C3 47n F 4 P ROSC 7 R4 C4 1 R3 C6 R2 20K 5 SW FB 2 C2 10 µF L1 D1 VOUT 12V, 0.7A R1 174K 10BQ015 Efficiency 95 10.5µH, 700KHz 90 85 4.7µH, 1.4MHz Efficiency (%) 80 3.3µH, 2MHz 75 70 65 60 All Capacitors are Ceramic. MSOP-8 Pinout f / MHz 0.7 1.35 2 R3 / KΩ 22.1 30.9 63.4 R4 / KΩ 22.1 9.31 4.75 C4 / p F 2200 820 470 C6 / p F 22 L1 / µH 10.5 (Falco D08019) 4.7 (Falco D08017) 3.3 (Coilcraft DO1813P) 55 50 0.0 0.1 0.2 0.3 0.4 VIN = 5V VOUT = 12V 0.5 0.6 0.7 Load Current (A) Figure 1(a). 5V to 12V Boost Converter. Figure 1(b). Efficiencies of 5V to 12V Boost Converters at 700KHz, 1.4MHz and 2MHz. 1 .semtech. Revision:...