SC4524SETRT View Datasheet(PDF) - Semtech Corporation
Part Name
Description
MFG CO.
SC4524SETRT Datasheet PDF : 21 Pages
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SC4524
POWER MANAGEMENT
Applications Information
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Bench measurement shows that compensation
components computed from our simplified linear model
give very good load transient response for the converter.
Board Layout Considerations
Figure 12. Fast Switching Current Paths in a Buck
Regulator. Minimize the size of this loop
to reduce parasitic trace inductance.
In a step-down switching regulator, the input bypass
capacitor, the main power switch and the freewheeling
GL
diode carry discontinuous currents with high GW (Figure
12). For jitter-free operation, the size of the loop formed
by these components should be minimized. Since the
power switches are already integrated within the SC4524,
connecting the anodes of both freewheeling diodes close
to the negative terminal of the input bypass capacitor
minimizes size of the switched current loop. The input
bypass capacitors should be placed close to the VIN pin.
Shortening the traces of the SW and BST nodes reduces
the parasitic trace inductance at these nodes. This not
only reduces EMI but also decreases switching voltage
spikes at these nodes.
The exposed pad should be soldered to a large analog
ground plane as the analog ground copper acts as a heat
sink for the device. To ensure proper adhesion to the
ground plane, avoid using vias directly under the device.
ã 2006 Semtech Corp.
19
www.semtech.com
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