
ISL6622
components such as lead inductances and PCB
capacitances are also not taken into account. Figure 8
provides a visual reference for this phenomenon and its
Gate Drive Voltage Options
Intersil provides various gate drive voltage options in the
ISL6622 product family, as shown in Table 2.
potential solution.
The ISL6622 can drop the low-side MOSFET’s gate drive
UVCC
BOOT
C BOOT
VIN
D
voltage when operating in DEM, while the high-side FET’s
gate drive voltage of the DFN package can be connected to
VCC or LVCC.
C GD
20k Ω
UGATE
G
R G
C GS
C DS
Q UPPER
S
The ISL6622A allows the low-side MOSFET(s) to operate
from an externally-provided rail as low as 5V, eliminating the
LDO losses, while the high-side MOSFET’s gate drive
voltage of the DFN package can be connected to VCC or
LVCC.
PHASE
FIGURE 8. GATE TO SOURCE RESISTOR TO REDUCE
UPPER MOSFET MILLER COUPLING
The ISL6622B sets the low-side MOSFET’s gate drive
voltage at a fixed, programmable LDO level, while the
high-side FETs’ gate drive voltage of the DFN package can
be connected to VCC or LVCC.
TABLE 2. ISL6622 FAMILY BIAS OPTIONS
LVCC
POWER RAILS
PSI = LOW
PSI = HIGH
UVCC
VCC
ISL6622
ISL6622A
SOIC
DFN
SOIC
5.75V
Programmable
Own Rail
11.2V
11.2V
VCC
Own Rail
VCC
Operating Voltage Ranges
from 6.8V to 13.2V
DFN
Own Rail
Own Rail
ISL6622B
SOIC
DFN
10
5.75V
Programmable
VCC
Own Rail
FN6470.2
October 30, 2008