ISL6310 Datasheet, PDF (7/27 Pages) Intersil Corporation – Two-Phase Buck PWM Controller with High Current Integrated MOSFET Drivers

Timing Diagram
t_PDHUGATE
UGATE
LGATE
t_FLGATE
ISL6310
t_RUGATE
Simplified Power System Diagram
+12V_IN
+5V_IN
2
REF0,REF1
ENLL
OVP
PGOOD
DAC
CHANNEL1
ISL6310
CHANNEL2
t_FUGATE
t_PDHLGATE
Q1
Q2
Q3
Q4
t_RLGATE
V_OUT
Functional Pin Description
VCC (Pin 3)
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.
PVCC (Pin 15)
Power supply pin for the MOSFET drive. This pin can be
connected to any voltage from +5V to +12V, depending on
the desired MOSFET gate drive level.
GND (Pin 33)
Bias and reference ground for the IC.
ENLL (Pin 20)
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.
7
FS (Pin 29)
A resistor, placed from FS to ground, will set the switching
frequency. Refer to Equation 43 and Figure 24 for proper
resistor calculation.
2PH (Pin 31)
This pin is used to choose between single or two phase
operation. Tying this pin to VCC allows for 2-Phase operation.
Tying the 2PH pin to GND causes the controller to operate in
a single phase mode.
REF0 and REF1 (Pins 30, 21)
These pins make up the 2-Bit input that selects the fixed DAC
reference voltage. These pins respond to TTL logic
thresholds. The ISL6310 decodes these inputs to establish
one of four fixed reference voltages; see Table 1 for
correspondence between REF0 and REF1 inputs and
reference voltage settings.
FN9209.4
August 7, 2008