ISL6522BIBZ Intersil, ISL6522BIBZ Datasheet - Page 12

• Manufacturer Part Number: ISL6522BIBZ
• Description: IC PWM BUCK BST VM 14SOIC
• Manufacturer: Intersil

Specifications of ISL6522BIBZ

• Pwm Type: Voltage Mode
• Number Of Outputs: 1
• Frequency - Max: 1MHz
• Duty Cycle: 100%
• Voltage - Supply: 10.8 V ~ 13.2 V
• Buck: Yes
• Boost: Yes
• Flyback: No
• Inverting: No
• Doubler: No
• Divider: No
• Cuk: No
• Isolated: No
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 14-SOIC (3.9mm Width), 14-SOL
• Frequency-max: 1MHz
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Figure 10 shows the upper gate drive supplied by a direct
connection to V
converter systems where the main input voltage is +5V
less. The peak upper gate-to-source voltage is
approximately V
power and +12V
of Q1 is 7V. A logic-level MOSFET is a good choice for Q1
and a logic-level MOSFET can be used for Q2 if its absolute
gate-to-source voltage rating exceeds the maximum voltage
applied to PV
ISL6522B
+
-
FIGURE 9. UPPER GATE DRIVE - BOOTSTRAP OPTION
+12V
VCC
CC
CC
CC
DC
.
+
GND
D
V
. This option should only be used in
BOOT
D
BOOT
UGATE
PHASE
LGATE
PGND
PVCC
less the input supply. For +5V main
for the bias, the gate-to-source voltage
-
+5V
OR +12V
C
BOOT
12
Q1
Q2
+5V OR +12V
D2
NOTE:
V
NOTE:
V
G-S
G-S
≈ V
≈ PVCC
CC
- V
DC
D
or
ISL6522B
FIGURE 10. UPPER GATE DRIVE - DIRECT V
Schottky Selection
Rectifier D2 is a clamp that catches the negative inductor
swing during the dead time between turning off the lower
MOSFET and turning on the upper MOSFET. The diode
must be a Schottky type to prevent the lossy parasitic
MOSFET body diode from conducting. It is acceptable to
omit the diode and let the body diode of the lower MOSFET
clamp the negative inductor swing, but efficiency will drop
one or two percent as a result. The diode's rated reverse
breakdown voltage must be greater than the maximum input
voltage.
ISL6522B
+
-
+12V
VCC
GND
BOOT
UGATE
PHASE
LGATE
PGND
PVCC
+5V
OR +12V
Q1
Q2
+5V OR LESS
D2
CC
V
NOTE:
NOTE:
V
G-S
DRIVE OPTION
G-S
≈ V
≈ PVCC
CC
- 5V