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FDMF8700 Rev. C3

Typical Application

Application Information

Supply Capacitor Selection

For the supply input (VCIN) of the FDMF8700, a local ceramic

bypass capacitor is recommended to reduce the noise and to

supply the peak current. Use at least a 1µF, X7R or X5R capac-

itor. Keep this capacitor close to the FDMF8700 VCIN and

CGND pins.

Bootstrap Circuit

and the internal diode, as shown in Figure 26. Selection of

these components should be done after the high-side MOSFET

has been chosen. The required capacitance is determined

using the following equation:

and

~300mV, the required bootstrap capacitance is > 100nF. A good

quality ceramic capacitor must be used.

by:

surge current rating of the internal diode should be checked

in-circuit, since this is dependent on the equivalent impedance

of the entire bootstrap circuit, including the PCB traces. For

in parallel to the internal diode.

(1)

(2)

PWM

CGND

PGND

VCIN

VIN

BOOT

VSWH

VCIN 12V

Signal

LDRV

HDRV

FDMF8700

DISB

VIN 12V

PWM

CGND

PGND

VCIN

VIN

BOOT

VSWH

LDRV

HDRV

FDMF8700

DISB

PWM

CGND

PGND

VCIN

VIN

BOOT

VSWH

LDRV

HDRV

FDMF8700

DISB

PWM

CGND

PGND

VCIN

VIN

BOOT

VSWH

LDRV

HDRV

FDMF8700

DISB

PWM3

EN

PWM1

PWM2

LDRV

PWM

Controller

VCC

PWM4

GND

Power

GND

VOUT

Figure 26. Typical Application