Datasheet

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   
   
SLVS215C − JUNE 1999 − REVISED AUGUST 2008
17
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
APPLICATION INFORMATION
applications proposals
paralleling of two TPS60110 to deliver 600 mA
The TPS60110 can be paralleled to yield higher load currents. The circuit of Figure 28 can deliver 600 mA at
an output voltage of 5 V. It uses two TPS60110 devices in parallel. The devices can share the output capacitors,
but each one requires its own transfer capacitors and input capacitor. For best performance, the paralleled
devices should operate in the same mode (pulse-skip or constant frequency).
IN
IN
C1+
C1−
ENABLE
OUT
OUT
FB
C2+
C2−
SYNC
SKIP COM CLK
PGND GND
INPUT
2.7 V to
5.4 V
10 µF
2.2 µF
2.2 µF
+
OFF/ON
TPS60110
IN
IN
C1+
C1−
ENABLE
OUT
OUT
FB
C2+
C2−
SYNC
SKIP COM CLK
PGND GND
15 µF
OUTPUT
5 V
300 mA
68 µF
2.2 µF2.2 µF
+
TPS60110
+
Figure 28. Paralleling of Two TPS60110
TPS60110 with LC output filter for ultra low ripple
For applications where extremely low output ripple is required, a small LC filter is recommended. This is shown
in Figure 29. The addition of a small inductor and filter capacitor will reduce the output ripple well below what
could be achieved with capacitors alone. The corner frequency of 500 kHz was chosen above the 300 kHz
switching frequency to avoid loop stability issues in case the feedback is taken from the output of the LC filter.
Leaving the feedback (FB) connection point before the LC filter, the filter capacitance value can be increased
to achieve even higher ripple attenuation without affecting stability margin.
IN
IN
C1+
C1−
ENABLE
OUT
OUT
FB
C2+
C2−
SYNC
SKIP COM CLK
PGND GND
INPUT
2.7 V to 5.4 V
C
IN
15 µF
OUTPUT
5 V 300 mA
C
O
= 33 µF
C
2F
2.2 µF
C
1F
2.2 µF
+
OFF/ON
TPS60110
+ 1 µF
+
0.1 µH
Figure 29. TPS60110 With LC Filter for Ultra Low Output Ripple Applications