Datasheet

C1
4.7 Fm
C2
4.7 Fm
C3
0.01 Fm
R1
332kW
R2
68.1kW
C5
0.015 Fm
C4
0.1 Fm
C7
47pF
R3
29.4kW
C6
1000pF
C8
47 Fm
C9
47 Fm
R5
10.2kW
R6
3.24kW
L1
10 Hm
TPS54231
www.ti.com SLUS851C –OCTOBER 2008–REVISED JULY 2012
APPLICATION INFORMATION
Figure 12. Typical Application Schematic
STEP BY STEP DESIGN PROCEDURE
The following design procedure can be used to select component values for the TPS54231. Alternately, the
SwitcherPro™Software may be used to generate a complete design. The SwitcherPro™ Software uses an
iterative design procedure and accesses a comprehensive database of components when generating a design.
This section presents a simplified discussion of the design process.
To begin the design process a few parameters must be decided upon. The designer needs to know the following:
• Input voltage range
• Output voltage
• Input ripple voltage
• Output ripple voltage
• Output current rating
• Operating frequency
For this design example, use the following as the input parameters
Table 3. Design Parameters
DESIGN PARAMETER EXAMPLE VALUE
Input voltage range 7 V to 28 V
Output voltage 3.3 V
Input ripple voltage 300 mV
Output ripple voltage 30 mV
Output current rating 2 A
Operating Frequency 570 kHz
SWITCHING FREQUENCY
The switching frequency for the TPS54231 is fixed at 570 kHz.
Copyright © 2008–2012, Texas Instruments Incorporated 11