LM2657MTCX

• The input voltage range is 4.5V to 28V
• Synchronous dual-channel interleaved switching
• Forced PWM or pulse skip mode
• Current sensing of lossless bottom-side FETs
• Adaptive duty cycle clamping
• High-current N-channel FET driver
• Low shutdown supply current
• Reference voltage accuracy of ± 1.5%
• 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
• 200kHz adjustable switching frequency - 500kHz
• Available in a TSSOP-28 package

illustrate

The LM2657 is an adjustable 200kHz-500kHz dual-channel voltage mode controlled high-speed synchronous buck regulator controller, ideal for high current applications. The LM2657 requires only N-channel FETs for each stage upper and lower position. It has feeders to improve response to input transients. At very light loads, the user can choose between a high-efficiency pulse-skipping mode or a fixed-frequency forced PWM mode. Lossless current without the use of an external sense resistor is limited by sensing, making it possible to detect the voltage drop of the FET at the bottom. A unique adaptive duty cycle clamping technique greatly reduces peak current when incorporated into normal load conditions. Two independent programmable output switches 180° out-of-phase (interleaved switching) reduce input capacitor and filter requirements. The input voltage range is 4.5V to 28V, while the output voltage is adjustable down to 0.6V.

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

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• Low output voltage high efficiency buck regulator