Rectifier Diode Selection (Boost Converter)

Output Capacitor Selection (Boost Converter)

Setting the Output Voltage (Boost Converter)

s

FB1

R1

R1

V

= V

1+

= 1.24 V

1+

R2

R2

æ

ö

æ

ö

´

´

ç

÷

ç

÷

è

ø

è

ø

(12)

F B1

V

1.24 V

R2 =

=

12 k

100

A

100

A

»

W

m

m

(13)

s

s

F B1

V

V

R1 = R2

1

= R2

1

V

1.24 V

æ

ö

æ

ö

´

-

´

-

ç

÷

ç

÷

è

ø

è

ø

(14)

TPS65166

Table 3. Inductor Selection Boost Converter (continued)

INDUCTOR VALUE

COMPONENT SUPLIER

SIZE (L×W×H mm)

Isat/DCR

10

µH

Sumida CDRH104R

10.3 × 10.5 × 4.0

4.4 A/26 m

Ω

10

µH

Sumida CDRH8D43

8.3 × 8.3 × 4.5

4 A/29 m

Ω

To achieve high efficiency a Schottky diode should be used. The reverse voltage rating should be higher than the

(10)

Usually a Schottky diode with 2A maximum average rectified forward current rating is sufficient for most

applications. The Schottky rectifier can be selected with lower forward current capability depending on the output

following equation:

(11)

Table 4. Rectifier Diode Selection (Boost Converter)

SIZE

COMPONENT SUPPLIER

20V/2A

0.44V at 2A

25°C/W

SMB

B220, DIODES Incorporated

20V/2A

0.44V at 2A

75°C/W

SMB

SL22, Vishay Semiconductor

20V/3A

0.44V at 3A

46°C/W

SMC

MBRS320, International Rectifier

For the best output voltage filtering, low ESR ceramic output capacitors are recommended. Three 22

µF or six

10

µF ceramic output capacitors with sufficient voltage rating in parallel are adequate for most applications.

Additional capacitors can be added to improve the load transient regulation. See Table 5 for output capacitor

selection.

Table 5. Output Capacitor Selection (Boost Converter)

CAPACITOR

COMPONENT SUPPLIER

22

µF/25V

Murata, GRM32ER61E226KE15

10

µF/25V

Murata, GRM31CR61E106KA12

10

µF/50V

Taiyo Yuden, UMK325BJ106MM

The output voltage is set by an external resistor divider. A minimum current of 100

µA through the feedback

divider provides good accuracy and noise covering. The resistors are calculated as:

22

Submit Documentation Feedback

Copyright © 2009, Texas Instruments Incorporated

Product Folder Link(s): TPS65166