ISL6219A_07 Datasheet, PDF (4/17 Pages) Intersil Corporation – Microprocessor CORE Voltage Regulator Precision Multi-Phase BUCK PWM Controller for Mobile Applications

ISL6219A
Functional Pin Descriptions
VID0, VID1, VID2, VID3, VID4 (Pins 1, 2, 3, 4, 5)
These are the inputs to the internal DAC that provide the
reference voltage for output regulation. Each pin has an
internal 20μA pull-up current source to 2.5V making the parts
compatible with CMOS and TTL logic from 5V down to 2.5V.
When a VID change is detected the reference voltage slowly
ramps up or down to the new value in 25mV steps. Connect
these pins to either open-drain or active-pull-up type outputs.
Pulling these pins above 2.9V can cause a reference offset
inaccuracy.
FS/EN (Pin 7)
This is a dual function pin. A resistor placed from FS/EN to
ground sets the switching frequency. There is an inverse
relationship between the value of the resistor and the
switching frequency. This pin can also be used to disable the
controller. To disable the controller, pull this pin below 1V.
FB (Pin 8) and COMP (Pin 9)
The internal error amplifier’s inverting input and output
respectively. These pins are connected to an external R-C
network to compensate the regulator.
GND (Pin 14)
Bias and signal ground for the IC.
VSEN (Pin 15)
Power good monitor input. Connect to the microprocessor
CORE voltage.
PWM3, PWM2, PWM1 (Pins 18, 21, 22)
Pulse-width modulation outputs. These logic outputs tell the
driver IC(s) when to turn the MOSFETs on and off.
ISEN3, ISEN2, ISEN1 (PINS 19, 20, 23)
Current sense inputs. A resistor connected between these
pins and the respective phase nodes has a current
proportional to the current in the lower MOSFET during its
conduction interval. The current is used as a reference for
channel balancing, load sharing, protection, and load-line
regulation.
PGOOD (Pin 25)
Power good. This pin is an open-drain logic signal that
indicates when the microprocessor CORE voltage (VSEN
pin) is within specified limits and soft-start has timed out.
VCC (Pin 28)
Bias supply voltage for the controller. Connect this pin to a
5V power supply.
4
FN9093.1
March 20, 2007