ISL6566_06 Datasheet, PDF (8/29 Pages) Intersil Corporation – Three-Phase Buck PWM Controller with Integrated MOSFET Drivers for VRM9, VRM10, and AMD Hammer Applications

Timing Diagram
t_PDHUGATE
UGATE
LGATE
t_FLGATE
ISL6566
t_RUGATE
Simplified Power System Diagram
+12V_IN
+5V_IN
5-6
VID
DAC
CHANNEL1
ISL6566
CHANNEL2
t_FUGATE
t_PDHLGATE
Q1
Q2
Q3
Q4
t_RLGATE
V_OUT
Q5
CHANNEL3
Q6
Functional Pin Description
VCC
VCC is the bias supply for the ICs small-signal circuitry.
Connect this pin to a +5V supply and locally decouple using
a quality 1.0µF ceramic capacitor.
PVCC1, PVCC2, PVCC3
These pins are the power supply pins for the corresponding
channel MOSFET drive, and can be connected to any
voltage from +5V to +12V, depending on the desired
MOSFET gate drive level.
The number of active channels is determined by the state of
PVCC2 and PVCC3. Leave PVCC3 unconnected or
grounded for 2-phase operation. For 1-phase operation
leave both PVCC3 and PVCC2 unconnected or grounded.
8
GND
GND is the bias and reference ground for the IC.
ENLL
This pin is a threshold-sensitive (approximately 0.66V) enable
input for the controller. Held low, this pin disables controller
operation. Pulled high, the pin enables the controller for
operation. ENLL has a internal 1.0µA pull-up to 5V.
FS
A resistor, placed from FS to ground, will set the switching
frequency. Refer to Equation 34 for proper resistor
calculation.
FN9178.4
March 9, 2006