FP6277 Application Information Inductor Selection Inductance value is decided based on different condition. 1.5uH to 4.7µH inductor value is recommended for general application circuit. There are three important inductor specifications, DC resistance, saturation current and core loss. Low DC resistance has better power efficiency. Also, avoid inductor saturation which will cause circuit system unstable and lower core loss at 500KHz. Capacitor Selection The output capacitor is required to maintain the VO DC voltage. Low ESR capacitors are preferred to reduce the output voltage ripple. Ceramic capacitor of X5R and X7R are recommended, which have low equivalent series resistance (ESR) and wider operation temperature range. Output Voltage Programming The output voltage is set by a resistive voltage divider from the output voltage to FB. The output voltage is: R1 VOUT 0.6 V 1 R 2 Layout Considerations 1. The power traces, consisting of the GND trace, the LX trace and the VIN trace should be kept short, direct and wide. 2. Layout LX switching node wide and short trace to reduce EMI. 3. Place C1 near VIN pin as closely as possible to maintain input voltage steady and filter out the pulsing input current. 4. The resistive divider R1 and R2 must be connected to FB pin directly and as closely as possible. 5. FB is a sensitive node. Please keep it away from switching node LX. 6. The GND of the IC, C1, C3 and C4 should be connected close together directly to a power ground plane. This datasheet contains new product information. Feeling Technology reserves the rights to modify the product specification without notice. No liability is assumed as a result of the use of this product. No rights under any patent accompany the sales of the product. Website: http://www.feeling-tech.com.tw Rev. 0.65 9/12
