ISL6560 Datasheet, PDF (2/14 Pages) Intersil Corporation – Microprocessor CORE Voltage Regulator Two-Phase Buck PWM Controller

ISL6560
Block Diagram
REF
VCC
PWRGD
VID4
VID3
VID2
D/A
VID1
VID0
FB
COMP
3V REFERENCE
X 0.82
X1.24
+
-
UV
+
-
OVP
E/A
+
-
UVLO and
BIAS CIRCUITS
OSCILLATOR
CONTROL
LOGIC
CMP
+
-
CT
PWM1
PWM2
CS+
CS-
GND
Simplified Power System Diagram
FB
ISL6560
PWM 1
SYNCHRONOUS
RECTIFIED BUCK
CHANNEL
PWM 2 ^SYNCHRONOUS
RECTIFIED BUCK
CHANNEL
VID
MICROPROCESSOR
Functional Pin Description
VID4 1
VID3 2
VID2 3
VID1 4
VID0 5
COMP 6
FB 7
CT 8
16 VCC
15 REF
14 CS-
13 PWM1
12 PWM2
11 CS+
10 PWRGD
9 GND
VID4 (Pin 1), VID3 (Pin 2), VID2 (Pin 3), VID1 (Pin 4)
and VID0 (Pin 5)
Voltage Identification inputs from microprocessor. These pins
respond to TTL and 3.3V logic signals. The ISL6560 decodes
VID bits to establish the output voltage. See Table 1.
COMP (Pin 6)
Output of the internal transconductance error amplifier.
Voltage at this pin sets the output current level of the current
sense comparator. Pulling this pin to ground disables the
oscillator and drives both PWM outputs low.
FB (Pin 7)
Inverting input of the internal transconductance error
amplifier.
CT (Pin 8)
A capacitor on this pin sets the frequency of the internal
oscillator.
GND (Pin 9)
All signals are referenced to this bias and reference ground pin.
PWRGD (Pin 10)
This pin is an internal open drain connection. A high voltage
level at this pin with a resistor connected to this pin and VCC
indicates that CORE voltage is at the proper level,
CS+ (Pin 11) and CS- (Pin 14)
These inputs monitor the supply current to the upper
MOSFETs. CS+ is connected directly to the decoupled
supply voltage and current sensing resistor. CS- is
connected to the other end of the current sensing resistor
and the upper MOSFET drains.
PWM2 (Pin 12) and PWM1 (Pin 13)
PWM outputs that are connected to the gate driver ICs.
REF (Pin 15)
Three volt supply used to bias the output of the
transconductance amplifier.
VCC (Pin 16)
Connect this bias supply pin to a 12V supply.
2
FN9011.3