LM2647LQ

• Input voltages range from 5.5V to 28V
• Synchronous dual-channel crossbar switch
• Forced PWM or pulse-skipping mode
• Lossless bottom-side FET current sensing
• Adaptive responsibility cycle clamping
• High current N-channel FET driver
• Low shutdown supply current
• The reference voltage is accurate to within 1.5% of ±
• The output voltage can be adjusted down to 0.6V
• Power good flag and chip enabled
• Undervoltage lockout
• Over-voltage / Under-voltage protection
• Soft-start and soft-shutdown
• Switching frequency adjustable from 200kHz - 500kHz

illustrate

The LM2647 is an adjustable 200 - 500kHz dual controlled voltage mode high speed synchronous buck regulator controller ideal for battery-powered applications such as notebook computers and notebook computers. The LM2647 requires only N-channel FETs at the upper and lower positions for each synchronization phase. It uses feed-forward to improve input transient response. At very light loads, the user can choose between a constant frequency of high-efficiency pulse-skipping mode or forced PWM mode. Lossless current limiting is possible without the use of an external sense resistor by sensing the voltage drop at the bottom FET. A unique adaptive duty cycle clamping technique is established to significantly reduce peak current under abnormal load conditions. Two independent programmable output switching stages (interleaved switching) 180° to reduce input capacitance and filter requirements. The input voltage range is 5.5V to 28V, while the output voltage can be as low as 0.6V.

Standard supervisory and control features include soft-start, power-good output undervoltage and overvoltage protection, undervoltage lockout, soft shutdown, and enable.

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• Notebook chipset power supply
• Low output voltage high efficiency buck regulator