IR3088AMTRPBF International Rectifier, IR3088AMTRPBF Datasheet - Page 7
![IC XPHASE W/FAULT DET 20L-MLPQ](/photos/7/48/74806/20_mlpq_sml.jpg)
IR3088AMTRPBF
Manufacturer Part Number
IR3088AMTRPBF
Description
IC XPHASE W/FAULT DET 20L-MLPQ
Manufacturer
International Rectifier
Series
XPhase™r
Datasheet
1.IR3088AMTRPBF.pdf
(33 pages)
Specifications of IR3088AMTRPBF
Applications
Processor
Current - Supply
10mA
Voltage - Supply
8.4 V ~ 14 V
Operating Temperature
0°C ~ 125°C
Mounting Type
Surface Mount
Package / Case
20-MLPQ
Pin Count
20
Mounting
Surface Mount
Package Type
MLPQ
Case Length
4mm
Case Height
0.88mm
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Other names
IR3088AMTRPBF
IR3088AMTRPBFTR
IR3088AMTRPBFTR
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Part Number:
IR3088AMTRPBF
Manufacturer:
IR
Quantity:
20 000
PWM Control Method
The PWM block diagram of the XPhase
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. An external RC circuit connected to the input voltage and ground is used to program the
slope of the PWM ramp and to provide the feed-forward control at each phase. 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
An oscillator with programmable frequency is located in the Control IC. The output of the oscillator is a 50% duty
cycle triangle waveform with peak and valley voltages of approximately 5V and 1V respectively. This signal is used to
program both the switching frequency and phase timing of the Phase ICs. The Phase IC is programmed by resistor
divider R
comparator in the Phase ICs detects the crossing of the oscillator waveform over the voltage generated by the
resistor divider and triggers a clock pulse that starts the PWM cycle. The peak and valley voltages track the VBIAS
voltage reducing potential Phase IC timing errors. Figure 3 shows the Phase timing for an 8 phase converter. Note
that both slopes of the triangle waveform can be used for phase timing by swapping the RMPIN+ and RMPIN– pins,
as shown in Figure 2.
+
-
50%
DUTY
CYCLE
Page 7 of 33
VBIAS
REGULATOR
CONTROL IC
RAMP GENERATOR
IFB
PHS1
+
-
ERROR
AMP
IROSC
VDAC
and R
VPEAK
VVALLEY
+
-
VDRP
AMP
VDRP
IIN
PHS2
RMPOUT
VBIAS
VDAC
VOSNS-
EAOUT
FB
connected between the VBIAS reference voltage and the Phase IC LGND pin. A
RVFB
RDRP
TM
architecture is shown in Figure 2. Feed-forward voltage mode control with
Figure 2. PWM Block Diagram
RPWMRMP
CPWMRMP
RPWMRMP
CPWMRMP
RPHS1
RPHS2
RPHS1
RPHS2
CSCOMP
CSCOMP
RAMPIN+
RAMPIN-
PWMRMP
RAMPIN+
RAMPIN-
PWMRMP
SCOMP
ISHARE
DACIN
SCOMP
ISHARE
DACIN
BIASIN
BIASIN
EAIN
EAIN
SHARE
ADJUST
ERROR
AMPLIFIER
SHARE
ADJUST
ERROR
AMPLIFIER
+
-
+
-
SYSTEM
REFERENCE
VOLTAGE
SYSTEM
REFERENCE
VOLTAGE
10K
10K
CLOCK
PULSE
GENERATOR
CLOCK
PULSE
GENERATOR
+
-
+
-
20mV
20mV
RAMP
DISCHARGE
CLAMP
RAMP
DISCHARGE
CLAMP
PWM
COMPARATOR
PWM
COMPARATOR
ENABLE
ENABLE
PHASE IC
PHASE IC
-
+
-
+
+
-
+
-
PWM
LATCH
DOMINANT
PWM
LATCH
DOMINANT
S
RESET
R
BODY
BRAKING
COMPARATOR
S
RESET
R
BODY
BRAKING
COMPARATOR
CURRENT
SENSE
AMPLIFIER
X34
CURRENT
SENSE
AMPLIFIER
X34
+
-
+
-
X
0.91
X
0.91
IR3088APbF
GATEH
GATEL
CSIN+
CSIN-
GATEH
GATEL
CSIN+
CSIN-
May 18, 2009
CCS
CCS
RCS
RCS
COUT
VIN
VOSNS+
VOUT
GND
VOSNS-