LTC4449 datasheet(12/18 Pages) AD

12 / 18 page

LTC7060

Rev. A

For more information www.analog.com

APPLICATIONS INFORMATION

BYPASSING AND GROUNDING

The LTC7060 requires proper bypassing on the VCC,

VBST-SW, and VBGVCC-BGRTN supplies due to its high

speed switching (nanoseconds) and large AC currents

(amperes). Careless component placement and PCB

trace routing may cause excessive ringing and under/

overshoot.

To obtain the optimum performance form the LTC7060:

• Mount the bypass capacitors as close as possible

between the VCC and SGND pins, the BGVCC and

BGRTN pins, and the BST and SW pins. The leads

should be shortened as much as possible to reduce

lead inductance.

• Use a low inductance, low impedance ground plane

to reduce any ground drop and stray capacitance.

Remember that the LTC7060 switches greater than

5A peak currents and any significant ground drop will

degrade signal integrity.

• Plan the power/ground routing carefully. Know where

the large load switching current is coming from and

going to. Maintain separate ground return paths for

the input pin and the output power stage.

• Kelvin connect the TG pin to the top MOSFET gate and

SW pin to the top MOSFET source. Kelvin connect

the BG pin to the bottom MOSFET gate and BGRTN

to the bottom MOSFET source. Keep the copper trace

between the driver output pin and load short and

wide.

• Be sure to solder the Exposed Pad on the back side of

the LTC7060 packages to the board. Failure to make

good thermal contact between the exposed back side

and the copper board will result in thermal resistances

far greater than specified for the packages.

LTC4449 Datasheet(PDF) 12 Page - Analog Devices