RT8015

14

DS8015-03

March 2011

www.richtek.com

Table 1. Recommended Inductor

Table 2. Recommended Capacitor

Layout Considerations

Follow the PCB layout guidelines for optimal performance of RT8015.

}

A ground plane is recommended. If a ground plane layer is not used, the signal and power grounds should be segregated

with all small-signal components returning to the GND pin at one point that is then connected to the PGND pin close

to the IC. The exposed pad should be connected to GND.

}

AC current into the internal power MOSFETs.

}

LX node is with high frequency voltage swing and should be kept small area. Keep all sensitive small-signal nodes

away from LX node to prevent stray capacitive noise pick-up.

}

Flood all unused areas on all layers with copper. Flooding with copper will reduce the temperature rise of power

components. You can connect the copper areas to any DC net (PVDD, VDD, VOUT, PGND, GND, or any other DC rail

in your system).

}

Connect the FB pin directly to the feedback resistors. The resistor divider must be connected between VOUT and

GND.

Figure 5

Component Supplier

Series

Inductance (uH) DCR (m

Ω) Current Rating (mA) Dimensions (mm)

TAIYO YUDEN

NR 4018

2.2

60

2700

4.00 x 4.00 x 1.80

Sumida

CDRH4D28

2.2

31.3

2040

4.50 x 4.50 x 3.00

GOTREND

GTSD53

2.2

29

2410

5.00x 5.00 x 2.80

TAIYO YUDEN

NR 4018

1.0

30

4000

4.00 x 4.00 x 1.80

Sumida

CDRH4D28C/LD

1.0

17.5

3000

4.50 x 4.50 x 3.00

GOTREND

GTSD53

1.0

15

4000

5.00x 5.00 x 2.80

Component Supplier

Part No.

Capacitance (uF)

Case Size

TDK

C3225X5R0J226M

22

1210

TDK

C3225X5R0J226M

22

1210

Panasonic

ECJ4YB0J226M

22

1210

Panasonic

ECJ4YB1A226M

22

1210

TAIYO YUDEN

LMK325BJ226ML

22

1210

TAIYO YUDEN

JMK316BJ226ML

22

1206

GND

L1

GND

R2

R1

GND as closer as possible

LX should be

connected to

Inductor by wide

and short trace,

keep sensitive

compontents away

from this trace

Output capacitor must be

near RT8015

Connect the FB pin directly to feedback resistors. The

COMP

VDD

SHDN/RT

LX

GND

FB

PGND

PVDD

4

5

6

3

2

8

7

1

RT8015