The FAN6520A simplifies implementing a complete control and protection scheme for a DC-DC stepdown converter. Designed to drive N-channel MOSFETs in a synchronous buck topology, the FAN6520A integrates the control, output adjustment, monitoring, and protection functions into a single 8-lead package.

The FAN6520A employs a single feedback loop and voltage-mode control with fast transient response. The output voltage can be precisely regulated to as low as 0.8V, with a maximum tolerance of ±1.5% over-temperature and line-voltage variations. A fixed-frequency oscillator reduces design complexity, while balancing typical application cost. The error amplifier features a 15MHz gain-bandwidth product and an 8V/µs slew rate, which enables high converter bandwidth for fast transient performance. The resulting PWM duty cycles range from 0% to 100%.

The IC monitors the drop across the upper MOSFET and inhibits PWM operation appropriately to protect against over-current conditions. This approach simplifies the implementation and improves efficiency by eliminating the need for a current sense resistor.

The FAN6520A is rated for operation from 0° to +70°C, with the FAN6520AI rated from –40° to +85°C.

• Output Range 0.8V to V_IN
  • 0.8V Internal Reference
  • ±1.5% Over Line Voltage and Temperature
• Drives N-Channel MOSFETs
• Simple Single-Loop Control Design
  • Voltage-Mode PWM Control
• Fast Transient Response
  • High-Bandwidth Error Amplifier
  • Full 0% to 100% Duty Cycle
• Lossless, Programmable Over-Current Protection
  • Uses Upper MOSFET's R_DS(ON)
• Small Converter Size
  • 300kHz Fixed Frequency Oscillator
  • Internal Soft-Start
  • 8-Lead SOIC

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