FP7201 datasheet(13/14 Pages) FEELING

13 / 14 page

FP7201

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. 0.70

13/14

FP7201

LED1

LED2

LED3

GND

OVP

VCC

VIN

VOUT

GND

CIN

COUT

Inductor Selection

Inductance value is decided based on different condition. 4.7 to 22µH inductor value is

recommended for 2 to 7 WLEDs applications. There are three important inductor specifications, DC

resistance, saturation current and core loss. Low DC resistance (DCR) has better power efficiency.

Also, it avoids inductor saturation causing circuit system unstably and lower core loss at 1.2MHz.

Capacitor Selection

The output capacitor is required to maintain the series LED voltage during . 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 temperature range.

Diode Selection

Schottky diodes have fast recovery times and low forward voltages are recommended. Ensure

that the diode average and peak current rating exceeds the average output current and peak inductor

current. In addition, the diode’s reverse breakdown voltage must exceed the open LED protection

voltage.

Layout Considerations

1. The power traces, consisting of the GND trace, the LX trace and the VCC trace should be kept

short, direct and wide.

2. LX、Inductance L and Diode D switching node, wide and short trace to reduce EMI.

3. Place CIN near VCC pin as closely as possible to maintain input voltage steady and filter out the

pulsing input current.

4. Feedback resistance R 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, CIN, COUT should be connected close together directly to a ground plane.

FP7201 Datasheet(PDF) 13 Page - Feeling Technology Corp.