尚途STI3411 V1.0

1.5A DC-DC

1.5MHz， 2A Synchronous Step-Down Converter

FEATURES • High Efficiency： Up to 96% • 1.5MHz Constant Frequency Operation • 2A Output Current • No Schottky Diode Required • 2.3V to 6V Input Voltage Range • Output Voltage as Low as 0.6V • PFM Mode for High Efficiency in Light Load • 100% Duty Cycle in Dropout Operation • Low Quiescent Current： 40μA • Short Circuit Protection • Thermal Fault Protection • Inrush Current Limit and Soft Start • 《1μA Shutdown Current • SOT23-6 package APPLICATIONS • Cellular and Smart Phones • Wireless and DSL Modems • PDAs • Portable Instruments • Digital Still and Video Cameras • PC Cards Figure 1. Basic Application Circuit GENERAL DESCRIPTION The STI3411 is a 1.5MHz constant frequency， current mode step-down converter. It is ideal for portable equipment requiring very high current up to 2A from single-cell Lithium-ion batteries while still achieving over 90% efficiency during peak load conditions. The STI3411 also can run at 100% duty cycle for low dropout operation， extending battery life in portable systems while light load operation provides very low output ripple for noise sensitive applications. The STI3411 can supply up to 2A output load current from a 2.3V to 6V input voltage and the output voltage can be regulated as low as 0.6V. The high switching frequency minimizes the size of external components while keeping switching losses low. The internal slope compensation setting allows the device to operate with smaller inductor values to optimize size and provide efficient operation. The STI3411 is offered in a low profile （1mm） 6-pin， thin SOT package， and is available in an adjustable version. This device offers two operation modes， PWM control and PFM Mode switching control， which allows a high efficiency over the wider range of the load.