LTC3867_15 Datasheet, PDF (32/36 Pages) Linear Technology – Low IQ, Dual 2-Phase Synchronous Step-Down Controller

LTC3867
APPLICATIONS INFORMATION
8. Are the signal and power grounds kept separate? The
combined IC signal ground pin and the ground return
of C_INTVCC must return to the combined C_OUT (–) ter-
minals. The V_FB and I_TH traces should be as short as
possible. The path formed by the top N-channel MOSFET,
Schottky diode and the C_IN capacitor should have short
leads and PC trace lengths. The output capacitor (–)
terminals should be connected as close as possible
to the (–) terminals of the input capacitor by placing
the capacitors next to each other and away from the
Schottky loop described above.
9. Use a modified “star ground” technique: a low imped-
ance, large copper area central grounding point on
the same side of the PC board as the input and output
capacitors with tie-ins for the bottom of the INTV_CC
decoupling capacitor, the bottom of the voltage feedback
resistive divider and the SGND pin of the IC.
3867f
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