aoz1212 Alpha & Omega Semiconductor, aoz1212 Datasheet - Page 11

• Manufacturer Part Number: aoz1212
• Description: 3a Simple Buck Regulator
• Manufacturer: Alpha & Omega Semiconductor

dissipation of converter circuit can be measured by input
power minus output power.
The power dissipation of inductor can be approximately
calculated by output current and DCR of the inductor.
The power dissipation of the diode is:
The actual AOZ1212 junction temperature can be
calculated with power dissipation in the AOZ1212 and
thermal impedance from junction to ambient.
The maximum junction temperature of AOZ1212 is
145°C, which limits the maximum load current capability.
The thermal performance of the AOZ1212 is strongly
affected by the PCB layout. Care should be taken by
users during design process to ensure that the IC will
operate under the recommended environmental
conditions.
P
P
P
T
Rev. 1.1 October 2007
diode_loss
total _loss
inductor _loss
junction
+ +
=
=
=
P
V
I
=
T
total _loss
O
IN
I
ambient
O
2
V
I
IN
F
R
–
inductor
–
P
V
1
inductor _loss
O
–
--------- -
V
V
I
IN
O
O
1.1
JA
www.aosmd.com
Several layout tips are listed below for the best electric
and thermal performance. Figure 3a and Figure 3b show
layout examples for the AOZ1212A and AOZ1212D
respectively.
1. Do not use thermal relief connection to the V
2. Input capacitor should be connected as close as
3. Make the current trace from LX pins to L to C
4. Pour copper plane on all unused board area and
5. Keep sensitive signal traces such as the trace
the GND pin. Pour a maximized copper area to the
GND pin and the V
possible to the V
GND as short as possible.
connect it to stable DC nodes, like V
connecting FB and COMP pins away from the
LX pins.
IN
IN
and GND pins.
pin to help thermal dissipation.
IN
, GND or V
AOZ1212
Page 11 of 19
IN
O
and
to
OUT
.