ISL8103 INTERSIL [Intersil Corporation], ISL8103 Datasheet - Page 7

• Manufacturer Part Number: ISL8103
• Description: Three-Phase Buck PWM Controller with High Current Integrated MOSFET Drivers
• Manufacturer: INTERSIL [Intersil Corporation]

Timing Diagram
Simplified Power System Diagram
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.
UGATE
LGATE
+12V
+5V
REF0,REF1
IN
IN
PGOOD
ENLL
OVP
t
PDHUGATE
7
t
FLGATE
2
ISL8103
DAC
t
RUGATE
ISL8103
CHANNEL1
CHANNEL2
CHANNEL3
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.
Q3
Q4
Q5
Q6
Q1
Q2
t
PDHLGATE
t
FUGATE
t
RLGATE
V
OUT
February 15, 2006
FN9246.0