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APPLICATION INFORMATION

GND

EN

FB

SW

MODE

V

2.7Vto6V

IN

C

10 F

IN

m

TPS62290DRV

L

2.2 H

1

m

R

360k

1

W

R

180k

2

W

C

22pF

1

C

10 F

OUT

m

V

1.8V,

1000mA

OUT

GND

EN

FB

SW

MODE

V

3.7Vto6V

IN

C

10 F

IN

m

TPS62290DRV

L

2.2 H

1

m

R

182k

2

W

R

820k

1

W

C

22pF

1

C

10 F

OUT

m

V

3.3V,

1000mA

OUT

OUTPUT VOLTAGE SETTING

V

1 )

R

1

R

OUTPUT FILTER DESIGN (INDUCTOR AND OUTPUT CAPACITOR)

Inductor Selection

TPS62290

SLVS764 – JUNE 2007

Figure 17. TPS62290DRV Adjustable 1.8 V

Figure 18. TPS62290DRV Adjustable 3.3 V

The output voltage can be calculated to:

33pF.

Route the FB line away from noise sources, such as the inductor or the SW line.

The TPS62260 is designed to operate with inductors in the range of 1.5

µH to 4.7µH and with output capacitors

in the range of 4.7

µF to 22µF. The part is optimized for operation with a 2.2µH inductor and 10µF output

capacitor. Larger or smaller inductor values can be used to optimize the performance of the device for specific

operation conditions. For stable operation, the L and C values of the output filter may not fall below 1

µH effective

inductance and 3.5

µF effective capacitance.

The inductor value has a direct effect on the ripple current. The selected inductor has to be rated for its dc

resistance and saturation current. The inductor ripple current (

∆I

The inductor selection has also impact on the output voltage ripple in PFM mode. Higher inductor values will

lead to lower output voltage ripple and higher PFM frequency, lower inductor values will lead to a higher output

voltage ripple but lower PFM frequency.

13

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