ISL78227 Datasheet, PDF (3/43 Pages) Intersil Corporation – 2-Phase Boost Controller with Integrated Drivers

Pin Configuration
ISL78227
ISL78227
(32 LD 5x5 WFQFN)
TOP VIEW
32 31 30 29 28 27 26 25
VCC 1
24 UG1
SLOPE 2
23 PH1
FB 3
22 LG1
COMP 4
SS 5
SGND
21 PVCC
20 PGND
IMON 6
19 LG2
TRACK 7
18 PH2
PGOOD 8
17 UG2
9 10 11 12 13 14 15 16
Functional Pin Description
PIN NAME
VCC
SLOPE
FB
COMP
SS
PIN #
1
2
3
4
5
DESCRIPTION
IC bias power input pin for the internal analog circuitry. A minimum 1µF ceramic capacitor should be used between VCC
and ground for noise decoupling purposes. VCC is typically biased by PVCC or an external bias supply with voltage ranging
from 4.75V to 5.5V. Since PVCC is providing pulsing drive current, a small resistor like 10Ω or smaller between PVCC and
VCC can help to filter out the noises from PVCC to VCC.
This pin programs the slope of the internal slope compensation. A resistor should be connected from the SLOPE pin to
GND. Please refer to “Adjustable Slope Compensation” on page 32 for how to select this resistor value.
The inverting input of the error amplifier for the voltage regulation loop. A resistor network must be placed between the
FB pin and the output rail to set the boost converter’s output voltage. Please refer to “Output Voltage Setting” on page 37
for more details.
There are also output overvoltage and undervoltage comparators monitoring this pin. Please refer to “Output Overvoltage
Fault Protection” and “Output Undervoltage Indication” on page 34 for more details.
The output of the transconductance error amplifier (Gm1) for the output voltage regulation loop. Place the compensation
network between the COMP pin and ground. Please refer to “Output Voltage Regulation Loop” on page 25 for more details.
The COMP pin voltage can also be controlled by the constant current control loop error amplifier (Gm2) output through
a diode (D_CC) when the constant current control loop is used to control the input average current. Please refer to
“Constant Current Control (CC)” on page 35 for more details.
A capacitor placed from SS to ground will set up the soft-start ramp rate and in turn determine the soft-start time. Please
refer to “Soft-Start” on page 30 for more details.
Submit Document Feedback
3
FN8808.2
February 24, 2016