zxld1362 Zetex Semiconductors plc., zxld1362 Datasheet - Page 24

• Manufacturer Part Number: zxld1362
• Description: 1a Led Driver With Internal Switch
• Manufacturer: Zetex Semiconductors plc.

Inductor selection
Recommended inductor values for the ZXLD1362 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 10-17). The inductor should be mounted as close to the device as
possible with low resistance connections to the LX and V
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 ZXLD1362 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.
The graph Figure 3 below can be used to select a recommended inductor based on maintaining
the ZXLD1362 case temperature below 60°C. For detailed performance characteristics for the
inductor values 68, 100, 150 and 220µH see graphs on pages 10-17.
Issue 1 - December 2007
© Zetex Semiconductors plc 2007
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Figure 3 ZXLD1362 Minimum recommended Inductor
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Aluminium board, 2% Accuracy, <60°C Case Temperature
ZXLD1362 Minimum Recommended Inductor
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Supply Voltage (V)
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ZXLD1362
www.zetex.com
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