OUT

OUT

FB

V

V

R1 = R2

1

= R2

1

V

0.8V

æ

ö

æ

ö

´

-

´

-

ç

÷

ç

÷

è

ø

è

ø

FB

FB

V

0.8 V

R2 =

=

160 k

I

5 A

»

OUT

FB

R1

R1

V

= V

1 +

= 0.8 V

1 +

R2

R2

æ

ö

æ

ö

´

´

ç

÷

ç

÷

è

ø

è

ø

V

V

OUT

OUT

x 1 -

η

V

x η

IN

I = I

+

L

OUT

2 x

x L

f

æ

ö

ç

÷

ç

÷

è

ø

I

L

I

= I

+

L

OUT

2

13

TLV62095

www.ti.com

SLVSDD3A – MARCH 2016 – REVISED JANUARY 2017

Product Folder Links: TLV62095

Submit Documentation Feedback

Copyright © 2016–2017, Texas Instruments Incorporated

(5)

(6)

where

ƒ = Converter switching frequency (typically 1.4MHz)

L = Inductor value

η = Estimated converter efficiency (use the number from the efficiency curves or 0.80 as a conservative

assumption)

Calculating the maximum inductor current using the actual operating conditions gives the minimum saturation

current. A margin of 20% should be added to cover for load transients during operation.

8.2.1.2.4

Input and Output Capacitor Selection

For best output and input voltage filtering, low ESR (X5R or X7R) ceramic capacitors are recommended. The

input capacitor minimizes input voltage ripple, suppresses input voltage spikes and provides a stable system rail

for the device. A 22-μF or larger input capacitor is recommended. The output capacitor value can range from 10

μF up to 150 μF and beyond. Load transient testing and measuring the bode plot are good ways to verify stability

with larger capacitor values.

The recommended typical output capacitor value is 2 x 22 μF (nominal) and can vary over a wide range as

outline in the output filter selection table. Ceramic capacitor have a DC-Bias effect, which has a strong influence

on the final effective capacitance. Choose the right capacitor carefully in combination with considering its

package size and voltage rating.

8.2.1.2.5

Setting the Output Voltage

The output voltage is set by an external resistor divider according to the following equations:

(7)

(8)

(9)

When sizing R2, in order to achieve low quiescent current and acceptable noise sensitivity, use a minimum of 5

µA for the feedback current IFB. Larger currents through R2 improve noise sensitivity and output voltage

accuracy.