CN5208

The CN5208 is a switch - mode PWM step - down DC - DC controller using few external components. It achieves 5A continuous output current over a wide input supply range with excellent load and line regulation. The output voltage is internally set at 5V. The high switching frequency of 550KHz allows tiny external components to be usable. The CN5208 is designed to be stable with ceramic output capacitor. Pulse skipping mode is adopted under light load for high efficiency. Furthermore, the low operating current and low dropout operation make the CN5208 is suitable for battery powered systems. Fault protection includes cycle - by - cycle current limit, short output protection and output overvoltage protection. In shutdown mode, the CN5208 draws only 7.5μA (VCC = 15V) of supply current. On - chip soft - start minimizes the inrush supply current and the output overshoot at initial startup. The CN5208 is available in a space - saving 8 - pin SOP package. The CN5208 is an asynchronous step - down (buck) DC to DC controller that drives an external P - channel MOSFET with few external components. The CN5208 regulates the output voltage with fixed frequency PWM mode, the wide input voltage range is from 4.8V to 32V, the output voltage is internally fixed at 5V, and the maximum output current can be up to 5A. The pulse skipping mode is adopted under light load conditions for high efficiency. The switching frequency is fixed at 550KHz, which makes the low - profile inductor usable in the application circuit. The on - chip resistor divider, high precision bandgap voltage and error amplifier make the accuracy of the output voltage within 1%. CN5208’s current consumption is only 460μA (Typical), also low drop - out mode is adopted when input voltage is close to the output voltage, which make the device suitable for battery powered system. The frequency foldback reduces the switching frequency to 110KHz by increasing off time during overcurrent conditions or short circuit condition to help control the inductor current. The other fault protection includes overvoltage protection, cycle - by - cycle inductor current limit, etc. The input high level of shutdown input (SHDN) puts the CN5208 into low - current shut down state The on - chip soft start can limit the inrush current on power up, or SHDN being pulled low from high level, or release from short circuit.

Applications

• Car Charger
• Set - Top Box, Modems
• Pre - regulator
• Distributed Power Systems
• Battery Chargers

Key features

• Wide Input Voltage: 4.8V to 32V Operating with an External P - Channel MOSFET
• Output Current Up to 5A
• Fixed Switching Frequency: 550KHz
• Fixed Output Voltage with 1% Accuracy
• Efficiency up to 95%
• Low Drop - Out Mode
• Stable with Low - ESR Output Ceramic Capacitor On - Chip Power - On Delay to Debounce Input Supply
• Cycle - by - Cycle Current Limit
• Overvoltage protection Frequency Foldback for Output Short Circuit Protection
• Built - in Soft Start
• High Efficiency at Light Load with Pulse Skipping Mode
• Shutdown Curent: 7.5μA typical at 15V
• Operating Ambient Temperature -40℃ to +85℃
• Available in 8 - Pin SOP Package Pb - free, Rohs - Compliant, Halogen Free