LTC3728EUH#TR Linear Technology, LTC3728EUH#TR Datasheet - Page 30

• Manufacturer Part Number: LTC3728EUH#TR
• Description: IC SW REG SYNC STP-DN DUAL 32QFN
• Manufacturer: Linear Technology
• Series: PolyPhase®r
• Type: Step-Down (Buck)r

Specifications of LTC3728EUH#TR

• Internal Switch(s): No
• Synchronous Rectifier: Yes
• Number Of Outputs: 2
• Voltage - Output: 0.8 ~ 5.5 V
• Current - Output: 3A
• Frequency - Switching: 250kHz ~ 550kHz
• Voltage - Input: 3.5 ~ 36 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 32-QFN
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Power - Output: -
• Other names: LTC3728EUHTR

APPLICATIONS INFORMATION
LTC3728
4. Are the SENSE
5. Is the INTV
30
signal ground. The R2 and R4 connections should not
be along the high current input feeds from the input
capacitor(s).
with minimum PC trace spacing? The fi lter capacitor
between SENSE
possible to the IC. Ensure accurate current sensing
with Kelvin connections at the SENSE resistor.
to the IC, between the INTV
pins? This capacitor carries the MOSFET drivers current
peaks. An additional 1μF ceramic capacitor placed im-
mediately next to the INTV
improve noise performance substantially.
R
CC
IN
V
decoupling capacitor connected close
IN
–
+
C
and SENSE
and SENSE
IN
BOLD LINES INDICATE
HIGH, SWITCHING
CURRENT LINES.
KEEP LINES TO A
MINIMUM LENGTH.
+
CC
CC
and PGND pins can help
+
–
and the power ground
should be as close as
leads routed together
Figure 11. Branch Current Waveforms
SW1
SW2
D1
D2
6. Keep the switching nodes (SW1, SW2), top gate nodes
7. Use a modifi ed “star ground” technique: a low imped-
L1
L2
(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 LTC3728 and occupy minimum
PC trace area.
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
decoupling capacitor, the bottom of the voltage feedback
resistive divider and the SGND pin of the IC.
R
R
SENSE1
SENSE2
C
C
OUT1
OUT2
V
V
+
+
OUT1
OUT2
3728 F11
R
R
L1
L2
3728fg
CC