LTC1628 LINER [Linear Technology], LTC1628 Datasheet - Page 28

• Manufacturer Part Number: LTC1628
• Description: High Efficiency, 2-Phase Synchronous Step-Down Switching Regulators
• Manufacturer: LINER [Linear Technology]

LTC1628/LTC1628-PG
APPLICATIO S I FOR ATIO
signal ground and a small V
should be as close as possible to the LTC1628 SGND pin.
The R2 and R4 connections should not be along the high
current input feeds from the input capacitor(s).
4. Are the SENSE
with minimum PC trace spacing? The filter capacitor
between SENSE
possible to the IC. Ensure accurate current sensing with
Kelvin connections at the SENSE resistor.
5. Is the INTV
the IC, between the INTV
28
CC
R
IN
decoupling capacitor connected close to
+
V
IN
–
and SENSE
U
C
and SENSE
IN
BOLD LINES INDICATE
HIGH, SWITCHING
CURRENT LINES.
KEEP LINES TO A
MINIMUM LENGTH.
+
CC
U
and the power ground pins?
OSENSE
–
+
should be as close as
leads routed together
W
decoupling capacitor
Figure 11. Branch Current Waveforms
SW1
SW2
U
D1
D2
This capacitor carries the MOSFET drivers current peaks.
An additional 1 F ceramic capacitor placed immediately
next to the INTV
performance substantially.
6. Keep the switching nodes (SW1, SW2), top gate nodes
(TG1, TG2), and boost nodes (BOOST1, BOOST2) away
from sensitive small-signal nodes, especially from the
opposites channel’s voltage and current sensing feedback
pins. All of these nodes have very large and fast moving
signals and therefore should be kept on the “output side”
of the LTC1628 and occupy minimum PC trace area.
L1
L2
R
R
SENSE1
SENSE2
C
C
OUT1
OUT2
CC
V
V
+
+
OUT1
OUT2
and PGND pins can help improve noise
1628 F11
R
R
L1
L2