RT9018A/B
Pin Description
Pin No.
PSOP-8
3
2
4
1
7
6
5
WDFN 3x3
7, 8, 9
6
10
5
4
1, 2, 3
--
VIN
EN
VDD
PGOOD
ADJ
VOUT
NC
Supply Input Voltage.
Chip Enable (Active-High).
Supply Voltage of Control Circuitry.
Power Good Open Drain Output.
Set the output voltage by the internal feedback resistors when
ADJ is grounded. If external feedback resistors is used, V
OUT
=
0.8V x (R1 + R2)/R2.
Output Voltage.
No Internal Connection.
Ground. The exposed pad must be soldered to a large PCB and
connected to GND for maximum power dissipation.
Pin Name
Pin Function
8,
Exposed Pad (11) GND
Exposed Pad (9)
Typical Application Circuit
V
OUT
=
0.8
×
R1
+
R2
R2
V
IN
10uF
Chip Enable
V
DD
1uF
V
OUT
VIN
VOUT
10uF
Chip Enable
V
DD
V
OUT
V
IN
10uF
VIN
VOUT
C
Dummy
R1
V
OUT
10uF
RT9018A/B
EN
VDD
GND
ADJ
PGOOD
100k
RT9018A/B
EN
VDD
GND
ADJ
PGOOD
R2
100k
V
OUT
1uF
Figure 1. Fixed Voltage Regulator
Figure 2. Adjustable Voltage Regulator
Function Block Diagram
VIN
OCP
VOUT
Driver
Error
Amplifier
OTP
+
-
EN
VDD
POR
0.8V
-
0.72V
+
Mode
ADJ
PGOOD
GND
www.richtek.com
2
DS9018A/B-04
September 2007
RICHTEK [ RICHTEK TECHNOLOGY CORPORATION ]
