AAT4900
Buffered Power Half-Bridge
Motor Drive
Recommended Decoupling Layout
Pattern
The AAT4900 is also ideally suited for use as an effi-
cient output driver for DC brushless motor control.
The inductive load switching capability of the
AAT4900 eliminates the need for external diodes. A
typical motor control circuit is illustrated in Figure 3.
Because of the extremely fast switching speed and
the high switching currents, optimum placement of
the input capacitor is critical. It is recommended
that a 0.1µF to 10µF 0805 or 1206 ceramic capac-
itor be placed as close as possible to the IC, as
shown in Figure 4. This helps to decouple the
switching transients from the stray inductance
present in the PC board.
Enable
+5V
IN
IN
EN
EN
AAT4900
LX
LX
AAT4900
Clock
CLK
GND
CLK
GND
DC Brushless
Motor
Ground
Figure 3: Typical Motor Control Block Diagram.
AAT4900
4 CLK
3 EN
2 GND
1 LX
5 V+
CAP
Figure 4: Recommended Decoupling Layout Pattern.
10
4900.2006.05.1.3
AAT [ ADVANCED ANALOG TECHNOLOGY, INC. ]
