LM2591 National Semiconductor, LM2591 Datasheet - Page 18

• Manufacturer Part Number: LM2591
• Description: SIMPLE SWITCHER Power Converter 150 kHz 1A Step-Down Voltage Regulator
• Manufacturer: National Semiconductor

www.national.com
Application Information
LAYOUT SUGGESTIONS
As in any switching regulator, layout is very important. Rap-
idly switching currents associated with wiring inductance can
generate voltage transients which can cause problems. For
minimal inductance and ground loops, with reference to
Figure 1, the wires indicated by heavy lines should be wide
printed circuit traces and should be kept as short as
possible. For best results, external components should be
located as close to the switcher lC as possible using ground
plane construction or single point grounding.
FIGURE 13. Inverting Regulator Ground Referenced Shutdown using Opto Device
FIGURE 12. Inverting Regulator Ground Referenced Shutdown
(Continued)
18
If open core inductors are used, special care must be
taken as to the location and positioning of this type of induc-
tor. Allowing the inductor flux to intersect sensitive feedback,
lC groundpath and C
When using the adjustable version, special care must be
taken as to the location of the feedback resistors and the
associated wiring. Physically locate both resistors near the
IC, and route the wiring away from the inductor, especially an
open core type of inductor.
OUT
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wiring can cause problems.
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