ISL6522BIBZ Intersil, ISL6522BIBZ Datasheet - Page 6

• 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

Functional Pin Descriptions
RT
This pin provides oscillator switching frequency adjustment.
By placing a resistor (R
200kHz switching frequency is increased according to the
following equation:
Conversely, connecting a pull-up resistor (R
to V
following equation:
OCSET
Connect a resistor (R
upper MOSFET. R
(I
the converter overcurrent (OC) trip point according to the
following equation:
I
An overcurrent trip cycles the soft-start function.
Fs 200kHz
Fs
PEAK
OCS
≈
≈
CC
200kHz
), and the upper MOSFET on-resistance (r
=
reduces the switching frequency according to the
I
------------------------------------------- -
OCS
COMP
+
r
–
DS ON
OCSET
5 10
------------------
4 10
------------------
•
EN
SS
FB
COMP
R
•
•
(
R
R
GND
OCSET
T
T
EN
RT
SS
FB
1
2
3
4
OCSET
6
7
)
OCSET
1
2
3
4
5
6
7
16
ISL6522B (SOIC)
5
ISL6522B (QFN)
T
) from this pin to GND, the nominal
(R
(R
TOP VIEW
TOP VIEW
, an internal 200µA current source
15
6
T
T
) from this pin to the drain of the
to 12V)
to GND)
6
14
7
13
8
14
13
12
11
10
9
8
12
11
10
9
VCC
LGATE
PGND
BOOT
UGATE
PHASE
PVCC
PVCC
LGATE
PGND
BOOT
T
) from this pin
DS(ON)
) set
ISL6522B
SS
Connect a capacitor from this pin to ground. This capacitor,
along with an internal 10µA current source, sets the soft-start
interval of the converter.
COMP and FB
COMP and FB are the available external pins of the error
amplifier. The FB pin is the inverting input of the error
amplifier and the COMP pin is the error amplifier output.
These pins are used to compensate the voltage-control
feedback loop of the converter.
EN
This pin is the open-collector enable pin. Pull this pin below
1V to disable the converter. In shutdown, the soft-start pin is
discharged and the UGATE and LGATE pins are held low.
GND
Signal ground for the IC. All voltage levels are measured
with respect to this pin.
PHASE
Connect the PHASE pin to the upper MOSFET source. This
pin is used to monitor the voltage drop across the MOSFET
for overcurrent protection. This pin also provides the return
path for the upper gate drive.
UGATE
Connect UGATE to the upper MOSFET gate. This pin
provides the gate drive for the upper MOSFET. This pin is also
monitored by the adaptive shoot through protection circuitry to
determine when the upper MOSFET has turned off.
BOOT
This pin provides bias voltage to the upper MOSFET driver.
A bootstrap circuit may be used to create a BOOT voltage
suitable to drive a standard N-Channel MOSFET.
PGND
This is the power ground connection. Tie the lower MOSFET
source to this pin.
LGATE
Connect LGATE to the lower MOSFET gate. This pin provides
the gate drive for the lower MOSFET. This pin is also
monitored by the adaptive shoot through protection circuitry to
determine when the lower MOSFET has turned off.
PVCC
Provide a bias supply for the lower gate drive to this pin.
VCC
Provide a 12V bias supply for the chip to this pin.