MPQ8903 – LOW DROPOUT, 150mA LINEAR REGULATOR
MPQ8903 Rev. 1.2 www.MonolithicPower.com 7
5/21/2010 MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.
© 2010 MPS. All Rights Reserved.
PCB layout guide
PCB layout is very important to achieve good
regulation, ripple rejection, transient response
and thermal performance. It is highly
recommended to duplicate EVB layout for
optimum performance.
If change is necessary, please follow these
guidelines and take figure 5 for reference.
1) Input and output bypass ceramic capacitors
are suggested to be put close to the IN Pin
and OUT Pin respectively.
2) Ensure all feedback connections are short
and direct. Place the feedback resistors and
compensation components as close to the
chip as possible.
3) Connect IN, OUT and especially GND
respectively to a large copper area to cool
the chip to improve thermal performance and
long-term reliability.
MPQ8903DJ
FB
OUT
4
5
GND
2
EN
IN
3
1
OUTPUT
V
IN
V
IN
C3
C2
C1
R3
R1
R2
C1
1
2
34
5VIN
EN
GND
FB
OUT
C3
VIN
VOUT
GND
R1
R2
C2
C3
R3
Top Layer
Figure 3—PCB Layout
