LT1370 Linear Technology, LT1370 Datasheet - Page 11

• Manufacturer Part Number: LT1370
• Description: 500kHz High Efficiency 6A Switching Regulator
• Manufacturer: Linear Technology

APPLICATIO S I FOR ATIO
Layout Considerations
For maximum efficiency, LT1370 switch rise and fall times
are made as short as possible. To prevent radiation and
high frequency resonance problems, proper layout of the
components connected to the switch node is essential. B
field (magnetic) radiation is minimized by keeping output
diode, switch pin and output bypass capacitor leads as
short as possible. Figure 3 shows recommended posi-
tions for these components. E field radiation is kept low by
minimizing the length and area of all traces connected to
the switch pin. A ground plane should always be used
under the switcher circuitry to prevent interplane
coupling.
U U
V
IN
W
Figure 3. Layout Considerations— R Package
V
C
FB
L1
S/S
SWITCH
NODE
GND
U
V
SW
NFB
CIRCULATING
V
Figure 4
FREQUENCY
D
IN
PATH
HIGH
The high speed switching current path is shown schemati-
cally in Figure 4. Minimum lead length in this path is
essential to ensure clean switching and low EMI. The path
including the switch, output diode and output capacitor is
the only one containing nanosecond rise and fall times.
Keep this path as short as possible.
More Help
For more detailed information on switching regulator
circuits, please see Application Note 19. Linear
Technology also offers a computer software program,
SwitcherCAD
ers. In addition, our Applications Department is always
ready to lend a helping hand.
SwitcherCAD is a trademark of Linear Technology Corporation.
C
C
KEEP PATH FROM
V
OUTPUT CAPACITORS
AND GROUND RETURN
AS SHORT AS POSSIBLE
SW
, OUTPUT DIODE,
TM
LOAD
, to assist in designing switching convert-
LT1370 • F03
LT1370 • F04
V
OUT
LT1370
11