KB3408 Datasheet | Kingbor Technology

FEATURES High Efficiency: Up to 96% Very Low Quiescent Current: Only 20µA .. During Operation - 350m A Output Current - 2.5V to 7.4V Input Voltage Range - 1.5MHz Constant Frequency Operation - No Schottky Diode Required - Low Dropout Operation: 100% Duty Cycle - 0.6V Reference Allows Low Output Voltages - Shutdown Mode Draws ) 1µA Supply Current - Current Mode Operation for Excellent Line and Load Transient Response - Overtemperature Protected - Low Profile (1mm) SOT23-5 Package - - DESCRIPTION The KB3408 is a high efficiency monolithic synchronous buck regulator using a constant frequency, current mode architecture. The device is available in an adjustable version and fixed output voltages of 1.8V and 3.3V. Supply current during operation is only 20µA and drops to ) 1µA in shutdown. The 2.5V to 7.4V input voltage range makes the KB3408 ideally suited for single Li-Ion battery-powered applications. 100% duty cycle provides low dropout operation, extending battery life in portable systems. Automatic Burst Mode operation increases efficiency at light loads, further extending battery life. Switching frequency is internally set at 1.5MHz, allowing the use of small surface mount inductors and capacitors. The internal synchronous switch increases efficiency and eliminates the need for an external Schottky diode. Low output voltages are easily supported with the 0.6V feedback reference voltage. The KB3408 is available in a low profile (1mm) SOT23-5 package. APPLICATIONS - - - - - - Cellular Telephones Personal Information Appliances Wireless and DSL Modems Digital Still Cameras MP3 Players Portable Instruments TYPICAL APPLICATION 95 90 VIN 2.7V TO 7.4V 4.7µH COUT 10µF CER 5 VOUT 1.8V 350m A VIN = 2.7V EFFICIENCY (%) + CIN 4.7µF Tan 1 VIN = 3.6V 80 VIN = 4.2V 75 70 65 60 0.1 VOUT = 1.8V 1 10 100 OUTPUT CURRENT (m A) 500 KB3408-1.8 RUN VOUT 2 Figure 1a. High Efficiency Step-Down Converter Figure 1b. Efficiency vs Load Current March...