ltc3586 Linear Technology Corporation, ltc3586 Datasheet - Page 33

• Manufacturer Part Number: ltc3586
• Description: High Ef? Ciency Usb Power Manager With Boost, Buck-boost And Dual Bucks
• Manufacturer: Linear Technology Corporation

Furthermore, due to its high frequency switching circuitry,
it is imperative that the input capacitors, inductors and
output capacitors be as close to the LTC3586 as possible
and that there be an unbroken ground plane under the
LTC3586 and all of its external high frequency components.
High frequency currents, such as the V
V
find their way along the ground plane in a myriad of paths
ranging from directly back to a mirror path beneath the
incident path on the top of the board. If there are slits or
cuts in the ground plane due to other traces on that layer,
the current will be forced to go around the slits. If high
frequency currents are not allowed to flow back through
their natural least-area path, excessive voltage will build
up and radiated emissions will occur. There should be a
group of vias under the grounded backside of the pack-
age leading directly down to an internal ground plane. To
minimize parasitic inductance, the ground plane should
be on the second layer of the PC board.
APPLICATIONS INFORMATION
IN3
, V
OUT3
, and V
OUT4
currents on the LTC3586, tend to
BUS
, V
IN1
, V
IN2
,
The GATE pin for the external ideal diode controller has
extremely limited drive current. Care must be taken to
minimize leakage to adjacent PC board traces. 100nA of
leakage from this pin will introduce an offset to the 15mV
ideal diode of approximately 10mV. To minimize leakage,
the trace can be guarded on the PC board by surrounding
it with V
less that one volt higher than GATE.
Figure 11. Higher Frequency Ground Currents Follow Their
Incident Path. Slices in the Ground Plane Cause High Voltage
and Increased Emmisions
OUT
connected metal, which should generally be
LTC3586
3586 F11
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