Datasheet

0
20
40
60
80
100
0.7
1.7 2.7
3.7
4.7
V - Input Voltage - V
I
h - Efficiency - %
I = 50 mA
O
I = 100 A
O
m
I = 10 mA
O
I = 1 mA
O
TPS61220, TPS61221, TPS61222
SLVS776A –JANUARY 2009–REVISED APRIL 2014 www.ti.com
For this example, if an output voltage of 4.2 V is needed, a 1.2-MΩ resistor is calculated for R
1
when 160 kΩ is
selected for R
2
. This would yield an output voltage of 4.25 V, neglecting resistor tolerances.
10.2.2.2.3 Inductor Selection
See Inductor Selection for a discussion on inductor choice.
10.2.2.2.4 Capacitor Selection
The procedure for selecting capacitors is the same as for the fixed output voltage circuit. See Capacitor
Selection.
10.2.2.3 Application Curves
Figure 27 shows the excellent efficiency of the converter, which remains above 80% with heavily discharged
cells.
Figure 27. TPS61220 Performance
16 Submit Documentation Feedback Copyright © 2009–2014, Texas Instruments Incorporated
Product Folder Links: TPS61220 TPS61221 TPS61222