zxld1366 Zetex Semiconductors plc., zxld1366 Datasheet - Page 25

• Manufacturer Part Number: zxld1366
• Description: High Accuracy 1a, 60v Led Driver With Internal Switch
• Manufacturer: Zetex Semiconductors plc.

Diode Selection
For maximum efficiency and performance, the rectifier (D1) should be a fast low capacitance
Schottky diode* with low reverse leakage at the maximum operating voltage and temperature.
They also provide better efficiency than silicon diodes, due to a combination of lower forward
voltage and reduced recovery time.
It is important to select parts with a peak current rating above the peak coil current and a
continuous current rating higher than the maximum output load current. It is very important to
consider the reverse leakage of the diode when operating above 85°C. Excess leakage will
increase the power dissipation in the device and if close to the load may create a thermal runaway
condition.
The higher forward voltage and overshoot due to reverse recovery time in silicon diodes will
increase the peak voltage on the LX output. If a silicon diode is used, care should be taken to
ensure that the total voltage appearing on the LX pin including supply ripple, does not exceed the
specified maximum value.
*A suitable Schottky diode would be B3100 (Diodes Inc).
Issue 2 - September 2008
© Diodes Incorporated 2008
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0.00
Figure 4 ZXLD1366 Minimum recommended inductor (DFN)
Legend
68µH
100µH
150µH
220µH
10.00
20.00
M in im u m R e c o m m e n d e d In d u c to r
2% A ccuracy, <60°C C ase T em perature
S u p p ly V o ltag e (V )
30.00
25
40.00
50.00
ZXLD1366
www.diodes.com
www.zetex.com
60.00