LTC3834 Linear Technology, LTC3834 Datasheet - Page 24

• Manufacturer Part Number: LTC3834
• Description: Synchronous Step-Down Controller
• Manufacturer: Linear Technology

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APPLICATIONS INFORMATION
LTC3834
high current output loading at lower input voltages, look
for inductive coupling between CIN, Schottky and the top
MOSFET components to the sensitive current and voltage
sensing traces. In addition, investigate common ground
path voltage pickup between these components and the
SGND pin of the IC.
An embarrassing problem, which can be missed in an
otherwise properly working switching regulator, results
24
V
IN
R
IN
BOLD LINES INDICATE HIGH SWITCHING
CURRENT. KEEP LINES TO A MINIMUM LENGTH.
C
IN
1nF
C1
Figure 9. LTC3834 Recommended Printed Circuit Layout Diagram
Figure 10. Branch Current Waveforms
D1
SW
D
C
B
B
when the current sensing leads are hooked up backwards.
The output voltage under this improper hookup will still
be maintained but the advantages of current mode control
will not be realized. Compensation of the voltage loop will
be much more sensitive to component selection. This
behavior can be investigated by temporarily shorting out
the current sensing resistor—don’t worry, the regulator
will still maintain control of the output voltage.
L1
C
IN
R
SENSE
M1
M2
C
OUT
V
OUT
D1
OPTIONAL
L1
3834 F10
C
3834 F09
OUT
R
L1
V
V
IN
OUT
3834fb