RT8009
Typical Application Circuit
L
4.7uH
1
3
5
4
V
V
OUT
IN
VIN
RT8009
LX
2.5V to 5.5V
C
IN
4.7uF
C
OUT
EN
VOUT
10uF
GND
2
Figure 1. Fixed Voltage Regulator
L
R1
R2
⎛
⎞
⎟
4.7uH
VOUT = VREF x 1+
⎜
1
V
5
IN
V
OUT
VIN
LX
⎝
⎠
2.5V to 5.5V
C
IN
C1
withR1+ R2 ≤ 1MΩ and
RT8009
4.7uF
R1
R2
VREF(Typ.) = 0.5V
C
OUT
3
4
EN FB
10uF
GND
2
Figure 2. Adjustable Voltage Regulator
Layout Guide
V
V
IN
V
V
L
L
OUT
IN
OUT
VIN
1
2
3
VIN
1
2
3
5
4
LX
5
4
LX
C
C
IN
C
C
IN
OUT
GND
OUT
GND
GND
GND
R2
V
R1
C1
OUT
EN
VOUT
EN
FB
Figure 3
Layout note:
1. The distance that CIN connects to VIN is as close as possible (Under 2mm).
2. COUT should be placed near RT8009.
www.richtek.com
2
DS8009-03 March 2007