ZXLD1356

ZXLD1356

Document number: DS33470 Rev. 3 - 2

22 of 29

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December 2010

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Inductor Selection

Recommended inductor values for the ZXLD1356 are in the range 68 µH to 220 µH.

Higher values of inductance are recommended at higher supply voltages in order to minimize errors due to switching delays,

which result in increased ripple and lower efficiency. Higher values of inductance also result in a smaller change in output current

over the supply voltage range. (see graphs pages 10-16). The inductor should be mounted as close to the device as possible

The chosen coil should have a saturation current higher than the peak output current and a continuous current rating above the

required mean output current.

Suitable coils for use with the ZXLD1356 may be selected from the MSS range manufactured by Coilcraft, or the NPIS range

manufactured by NIC components. The following websites may be useful in finding suitable components

www.coilcraft.com

www.niccomp.com

www.wuerth-elektronik.de

The inductor value should be chosen to maintain operating duty cycle and switch 'on'/'off' times within the specified limits over

the supply voltage and load current range.

Figures 3 and 4 (following) can be used to select a recommended inductor based on maintaining the ZXLD1356 case

temperature below 60°C for the different package types. For detailed performance characteristics for the inductor values 68, 100,

150 and 220µH see graphs on pages 10-16.

Figure 3. ZXLD1356 Minimum Recommended Inductor

Minimum Recommended Inductor

2% Accuracy, <60°C Case Temperature

0

1020

304050

60

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2

3

4

5

6

7

8

9

10

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12

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14

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Supply Voltage (V)

Legend

68uH

100uH

150uH

220uH