IR3527MTRPBF International Rectifier, IR3527MTRPBF Datasheet - Page 7

• Manufacturer Part Number: IR3527MTRPBF
• Description: IC CTRL XPHASE3 DUAL 24-MLPQ
• Manufacturer: International Rectifier
• Series: XPhase3™r

Specifications of IR3527MTRPBF

• Applications: Processor
• Current - Supply: 8mA
• Voltage - Supply: 8 V ~ 28 V
• Operating Temperature: 0°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: *
• Package: 24-Lead MLPQ
• Circuit: X-Phase Phase IC
• Iout (a): 1.3A Gate Driver
• Pbf: PbF Option Available
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

SYSTEM THEORY OF OPERATION
PWM Control Method
The PWM block diagram of the XPhase3
with trailing edge modulation is used. A high-gain and wide-bandwidth voltage type error amplifier is used for the
voltage control loop. Input voltage is sensed by phase to monitor any changes in amplitude. The PWM ramp slope
will change with the input voltage and automatically compensate for changes in the input voltage. The input voltage
can change due to variations in the silver box output voltage or due to the wire and PCB-trace voltage drop related
to changes in load current.
Frequency and Phase Timing Control
The oscillator is located in the Control IC and the system clock frequency is programmable from 250 kHz to 9 MHZ
by an external resistor. The control IC system clock signal (CLKOUT) is connected to CLKIN of all the phase ICs.
The phase timing of the phase ICs is controlled by the daisy chain loop, where control IC phase clock output
(PHSOUT) is connected to the phase clock input (PHSIN) of the first phase IC, and PHSOUT of the first phase IC is
connected to PHSIN of the second phase IC, etc. and PHSOUT of the last phase IC is connected back to PHSIN of
the control IC.
The switching frequency is set by the Control IC. The clock frequency equals the total number of phases multiplied
by the switching frequency. During power up, the control IC sends out clock signals from both CLKOUT and
PHSOUT pins and detects the feedback at PHSIN pin to determine the phase number and monitor any fault in the
daisy chain loop.
The IR3527 combines 2 Phase ICs in a single package. IR3527 internally connect the PHSOUT1 pin to the PHSIN2
so the firing order is always sequential. Figure 3 shows the phase timing for a four phase converter implemented by
two IR3527 Phase ICs. The dotted lines indicate the PHSOUT1 to PHSIN2 waveform that would be internal to the
IR3527.
Note 1: Guaranteed by design, but not tested in production
Note 2: VCCL-0.5V or VCC – 2.5V, whichever is lower
PSI Comparator
Rising Threshold Voltage
Falling Threshold Voltage
Hysteresis
Resistance
Floating Voltage
General
VCC Supply Current
VCC Supply Current
VCCLx Supply Current
BOOSTx Supply Current
DACIN Bias Current
SW Floating Voltage
Page 7 of 20
PARAMETER
8V
10V
4.75V
TM
architecture is shown in Figure 2. Feed-forward voltage mode control
(
BOOSTx)-V(SWX)
TEST CONDITION
8V
MIN
520
400
200
800
-3.0
2.2
2.2
3.1
0.5
0.1
50
TYP
-1.5
620
550
500
8.0
4.0
8.0
1.5
0.3
70
MAX
1150
V3.0
12.2
12.1
700
650
120
850
8.0
0.4
IR3527
3
1
UNIT
mV
mV
mV
mV
mA
mA
mA
mA
PA
V