Datasheet
Layout Considerations
V
I
GND
EN
SW
FB
C1
4.7 µF
L1
4.7 µH
C2
10 µF
TPS62220
V
I
2.5 V − 6 V
V
O
1.8 V / 400 mA
R1
R2
C1
C2
Typical Applications
V
I
GND
EN
SW
FB
C3
10 µF
L1
10 µH
C4
10 µF
TPS62220
V
I
3.6 V to 6 V
V
O
3.3 V/400 mA
R1
680 kΩ
R2
120 kΩ
C1
10 pF
C2
150 pF
1
2
3
5
4
V
I
GND
EN
SW
FB
C3
4.7 µF
L1
10 µH
C4
10 µF
TPS62220
V
I
2.7 V to 6 V
V
O
2.5 V/400 mA
R1
510 kΩ
R2
130 kΩ
C1
15 pF
C2
150 pF
1
2
3
5
4
TPS62220 , , TPS62221 , , TPS62222
TPS62223 , TPS62224 , TPS62225
TPS62227 , TPS62228 , TPS62229
SLVS491E – SEPTEMBER 2003 – REVISED FEBRUARY 2009 .......................................................................................................................................
www.ti.com
For all switching power supplies, the layout is an important step in the design, especially at high-peak currents
and switching frequencies. If the layout is not carefully done, the regulator shows stability problems as well as
EMI problems. Therefore, use wide and short traces for the main current paths, as indicated in bold in Figure 16 .
The input capacitor, as well as the inductor and output capacitor, should be placed as close as possible to the IC
pins. In particular, the input capacitor needs to be placed as close as possible to the IC pins, directly across the
Vin and GND pin. The feedback resistor network must be routed away from the inductor and switch node to
minimize noise and magnetic interference. To further minimize noise from coupling into the feedback network
and feedback pin, the ground plane or ground traces must be used for shielding. This becomes important
especially at high switching frequencies of 1.25 MHz.
Figure 16. Layout Diagram
Figure 17. LI-Ion to 3.3-V Conversion
Figure 18. LI-Ion to 2.5-V Conversion
16 Submit Documentation Feedback Copyright © 2003 – 2009, Texas Instruments Incorporated
Product Folder Link(s): TPS62220 TPS62221 TPS62222 TPS62223 TPS62224 TPS62225 TPS62227 TPS62228
TPS62229