IR3504MTRPBF International Rectifier, IR3504MTRPBF Datasheet - Page 10

• Manufacturer Part Number: IR3504MTRPBF
• Description: IC CTRL XPHASE3 SVID 32-MLPQ
• Manufacturer: International Rectifier
• Series: XPhase3™r

Specifications of IR3504MTRPBF

• Applications: Processor
• Current - Supply: 10mA
• Voltage - Supply: 4.75 V ~ 7.5 V
• Operating Temperature: 0°C ~ 100°C
• Mounting Type: Surface Mount
• Package / Case: *
• Package: 32-Lead MLPQ
• Circuit: X-Phase Control IC
• Switch Freq (khz): 250kHz to 1.5MHz
• 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 wide-bandwidth voltage type error amplifier in the Control IC is
used for the voltage control loop. Input voltage is sensed in phase ICs and feed-forward control is realized. The
PWM ramp slope will change with the input voltage automatically compensating 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. The last phase IC (PHSOUT) is connected back to PHSIN of the
control IC to complete the loop. 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 monitors for any fault in
the daisy chain loop. Figure 5 shows the phase timing for a four phase converter.
IR3504 CONTROL IC
ERROR
AMPLIFIER
Output 1 Only
IFB1
CLOCK GENERATOR
Page 10
REMOTE SENSE
AMPLIFIER
+
-
VDRP1 AMP
IROSC
+
-
VDAC
+
-
VDRP1
IIN1
CLKOUT
PHSOUT
PHSIN
VOUT1
VDAC1
LGND
EAOUT1
FB1
RCP1
CCP11
CCP12
RFB12
CFB1
CDRP1
GATE DRIVE
VOLTAGE
RFB11
RDRP1
Figure 4 - PWM Block Diagram
TM
architecture is shown in Figure 4. Feed-forward voltage mode control
PHSOUT
PHSOUT
ISHARE
DACIN
ISHARE
DACIN
CLKIN
PHSIN
CLKIN
PHSIN
EAIN
EAIN
3K
3K
CLK
D
CLK
D
SHARE ADJUST
ERROR AMPLIFIER
SHARE ADJUST
ERROR AMPLIFIER
Q
Q
+
-
+
-
RAMP
DISCHARGE
CLAMP
RAMP
DISCHARGE
CLAMP
ENABLE
ENABLE
PWM
COMPARATOR
-
PWM
COMPARATOR
-
VID6
VID6
+
+
VID6
VID6
VID6
VID6
-
+
-
+
+
-
+
-
PHASE IC
PHASE IC
BODY
BRAKING
COMPARATOR
BODY
BRAKING
COMPARATOR
PWM
LATCH
DOMINANT
PWM
LATCH
DOMINANT
S
RESET
R
S
RESET
R
VID6
VID6
VID6
VID6
+
+
+
+
CURRENT
SENSE
AMPLIFIER
CURRENT
SENSE
AMPLIFIER
+
-
+
-
CSIN-
CSIN-
VCC
VCCH
GATEH
SW
VCCL
GATEL
PGND
CSIN+
VCC
VCCH
GATEH
SW
VCCL
GATEL
PGND
CSIN+
CCS
CCS
July 28, 2009
RCS
RCS
CBST
CBST
IR3504
COUT
VIN
VOSNS1+
VOUT1
GND
VOSNS1-