ISL78227
Pin Configuration
32 LD 5x5 WFQFN
TOP VIEW
32 31 30 29 28 27 26 25
VCC
SLOPE
FB
UG1
PH1
1
2
3
4
5
6
7
8
24
23
22
21
20
19
18
17
LG1
COMP
SS
PVCC
PGND
LG2
SGND
IMON
TRACK
PGOOD
PH2
UG2
9
10 11
12 13 14 15 16
Functional Pin Description
PIN NAME
PIN #
DESCRIPTION
VCC
1
IC bias power input pin for the internal analog circuitry. Use a minimum 1µF ceramic capacitor 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.
Because PVCC provides pulsing drive current, a small resistor (10Ω or smaller) between PVCC and VCC can help filter out the
noises from PVCC to VCC.
SLOPE
FB
2
3
Programs the slope of the internal slope compensation. A resistor should be connected from the SLOPE pin to GND. Refer to
“Adjustable Slope Compensation” on page 32 for information about 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. Refer to “Output Voltage Setting” on page 37 for more details.
Output overvoltage and undervoltage comparators also monitor this pin. Refer to “Output Overvoltage Fault Protection” and
“Output Undervoltage Indication” on page 34 for more details.
COMP
4
5
The output of the transconductance error amplifier (Gm1) for the output voltage regulation loop. Place the compensation
network between the COMP pin and ground. 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 ) when the constant current control loop is used to control the input average current. Refer to “Constant Current Control
CC
(CC)” on page 35 for more details.
SS
A capacitor placed from SS to ground sets up the soft-start ramp rate and in turn, determines the soft-start time. Refer to
“Soft-Start” on page 30 for more details.
FN8808 Rev.6.00
Oct 22, 2021
Page 3 of 43