ISL6308 Datasheet, PDF (7/27 Pages) Intersil Corporation – Three-Phase Buck PWM Controller with High Current Integrated MOSFET Drivers

Timing Diagram
t_PDHUGATE
UGATE
LGATE
t_FLGATE
ISL6308
t_RUGATE
Simplified Power System Diagram
+12V_IN
+5V_IN
2
REF0,REF1
ENLL
OVP
PGOOD
DAC
CHANNEL1
ISL6308
CHANNEL2
t_FUGATE
t_PDHLGATE
Q1
Q2
Q3
Q4
t_RLGATE
V_OUT
Q5
CHANNEL3
Q6
Functional Pin Description
VCC (Pin 6)
Bias supply for the IC’s small-signal circuitry. Connect this
pin to a +5V supply and locally decouple using a quality
1.0µF ceramic capacitor.
PVCC1, PVCC2, PVCC3 (Pins 33, 24, 18)
Power supply pins for the corresponding channel MOSFET
drive. These pins can be connected to any voltage from +5V
to +12V, depending on the desired MOSFET gate drive level.
Note that tying PVCC2 OR PVCC3 to GND has the same
effect as tying 2PH or 3PH to GND for disabling the
corresponding phase
GND (Pin 41)
Bias and reference ground for the IC.
7
ENLL (Pin 37)
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.
FS (Pin 36)
A resistor, placed from FS to ground, will set the switching
frequency. Refer to Equation (33) and Figure 23 for proper
resistor calculation
3PH and 2PH (Pins 1, 2)
These pins decide how many phases the controller will
operate. Tying both pins to VCC allows for 3-phase operation.
Tying the 3PH pin to GND causes the controller to operate in
2-phase mode, while connecting both 3PH and 2PH GND will
allow for single phase operation.
FN9208.2
October 19, 2005