LTC3838-1_15 Datasheet, PDF (42/52 Pages) Linear Technology – Dual, Fast, Accurate Step-Down DC/DC Controller with Dual Differential Output Sensing

LTC3838-1
APPLICATIONS INFORMATION
V_IN
R_IN
C_IN
BOLD LINES INDICATE
HIGH SWITCHING
CURRENT. KEEP LINES
TO A MINIMUM LENGTH.
SW2
L2
R_{SENSE2 VOUT2}
C_OUT2
R_L2
SW1
L1
R_{SENSE1 VOUT1}
C_OUT1
R_L1
38381 F15
Figure 15. Branch Current Waveforms
• Use sufficient isolation when routing a clock signal into
the MODE/PLLIN pin or out of the CLKOUT pin, so that
the clock does not couple into sensitive pins.
• Place the ceramic decoupling capacitor C_INTVCC between
the INTV_CC pin and SGND and as close as possible to
the IC.
• Place the ceramic decoupling capacitor C_DRVCC close
to the IC, between the combined DRV_CC1,2 pins and
PGND.
• Filter the V_IN input to the LTC3838-1 with an RC filter.
Place the filter capacitor close to the V_IN pin.
• If vias have to be used, use immediate vias to connect
components to the SGND and PGND planes of LTC3838‑1.
Use multiple large vias for power components.
• Flood all unused areas on all layers with copper. Flooding
with copper will reduce the temperature rise of power
components. Connect the copper areas to DC rails only,
e.g., PGND.
42
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38381f