Richtek RT6239A

Description

The RT6239A/B is a high-performance 500kHz, 9A step-down regulator with internal power switches and synchronous rectifiers. It features quick transient response using its Advanced Constant On-Time (ACOTTM) control architecture that provides stable operation with small ceramic output capacitors and without complicated external compensation, among other benefits. The input voltage range is from 4.5V to 18V and the output is adjustable from 0.7V to 8V. The proprietary ACOTTM control improves upon other fast response constant on-time architectures, achieving nearly constant switching frequency over line, load, and output voltage ranges. Since there is no internal clock, response to transients is nearly instantaneous and inductor current can ramp quickly to maintain output regulation without large bulk output capacitance. The RT6239A/B is stable with and optimized for ceramic output capacitors. With internal 30mΩ switches and 12mΩ synchronous rectifiers, the RT6239A/B displays excellent efficiency and good behavior across a range of applications, especially for low output voltages and low duty cycles. Cycle-by-cycle current limit provides protection against shorted outputs, input under-voltage lockout, externally-adjustable soft-start, output under- and over-voltage protection, and thermal shutdown provide safe and smooth operation in all operating conditions. The RT6239A/B is available in the UQFN-14L 2x3 (FC) package, with exposed thermal pad.

Features

• Fast Transient Response
• Advanced Constant On-Time (ACOTTM) Control
• 4.5V to 18V Input Voltage Range
• Adjustable Output Voltage from 0.7V to 8V
• 9A Output Current
• 30mInternal High-Side N-MOSFET and 12mInternal Low-Side N-MOSFET
• Steady 500kHz Switching Frequency
• Up to 95% Efficiency
• Optimized for All Ceramic Capacitors
• Externally-Adjustable, Pre-Biased Compatible Soft-Start
• Cycle-by-Cycle Current Limit
• Input Under-Voltage Lockout
• Output Over- and Under-Voltage Protection
• Power Good Output
• Thermal Shutdown

Typical applications

• Computer Peripherals
• Industrial and Commercial Low Power Systems / Point of Load Regulation for High-Performance DSPs, FPGAs, and ASICs
• LCD Monitors and TVs / Green Electronics/Appliances

More information

• Datasheet