SC32300ASLASHB.EVB datasheet(12/18 Pages) SEMTECH

12 / 18 page

SC32300B

management.

J = TA + Pd θJA

Where:

J is the junction temperature

A is the ambient temperature

JA is the thermal resistance, 42

C/W

There is a temperature monitor in the driver which will shut

down the driver outputs and the LDO when the junction

temperature reaches 150OC. The driver will automatically

recover when the junction temperature cools to less than

132OC.

Layout Recommendations

The SC32300B is designed to provide strong source and

sink capability for MOSFET drive at high frequency. In

order to achieve this objective, the PCB layout is critical.

Some guidelines are highlighted below to achieve good

performance with SC32300B.

A. Locate the driver as close as possible to the MOSFETs.

For a high conversion ratio buck converter (e.g. 12V input

to 1V output), locate the driver as close as possible to the

low-side MOSFET.

B. Mount the decoupling capacitors as close as possible

between the VIN pin and the GND pin, the VDD pin and

the GND pin, the BST pin and the LX pin.

C. Minimize the PCB trace length between the DL pin to

the low-side MOSFET gate, the GND pin and the source of

the low-side MOSFET. Avoid mixing the ground trace of

the drive loop with the power stage current path.

D. Apply a similar rule for the high-side drive loop.

E. Use wide PCB trace > 20 mils for the drive loops.

F. Use two or more vias if the PCB trace for the drive loops

needs to be routed from one layer to another.

G. The ground of the input signals (PWM, FCCM and DT)

should be separated from the power ground plane and

directly connected to the GND pin of the driver.

Application Information (Continued)

H. Use multiple vias to connect the thermal pad to the

ground plane.

SC32300A/B.EVB Datasheet(PDF) 12 Page - Semtech Corporation