IR3084UMTRPBF International Rectifier, IR3084UMTRPBF Datasheet - Page 32

• Manufacturer Part Number: IR3084UMTRPBF
• Description: IC CTLR XPHASE 28-MLPQ
• Manufacturer: International Rectifier
• Series: XPhase™r

Specifications of IR3084UMTRPBF

• Package / Case: 28-MLPQ
• Mounting Type: Surface Mount
• Current - Supply: 14mA
• Voltage - Supply: 9.5 V ~ 16 V
• Operating Temperature: 0°C ~ 100°C
• Applications: Processor
• Package: 28-Lead MLPQ
• Circuit: X-Phase Control IC
• Switch Freq (khz): 150kHz to 1.0MHz
• Pbf: PbF Option Available
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Over Temperature Setting Resistors R
The threshold voltage of VRHOT comparator is proportional to the die temperature T
Determine the relationship between the die temperature of phase IC and the temperature of the power converter
according to the power loss, PCB layout and airflow etc, and then calculate HOTSET threshold voltage
corresponding to the allowed maximum temperature from Equation (21).
There are two ways to set the over temperature threshold, central setting and local setting. In the central setting,
only one resistor divider is used, and the setting voltage is connected to HOTSET pins of all the phase ICs. To
reduce the influence of noise on the accuracy of over temperature setting, a 0.1uF capacitor should be placed
next to HOTSET pin of each phase IC. In the local setting, a resistor divider per phase is needed, and the setting
voltage is connected to HOTSET pin of each phase. The 0.1uF decoupling capacitor is not necessary. Use
VBIAS as the reference voltage. If R
Phase Delay Timing Resistors R
The phase delay of the interleaved multiphase converter is programmed by the resistor divider connected at
RMPIN+ or RMPIN− depending on which slope of the oscillator ramp is used for the phase delay programming of
phase IC, as shown in Figure 4.
If the positive slope is used, RMPIN+ pin of the phase IC should be connected to RMPOUT pin of the control IC
and RMPIN− pin should be connected to the resistor divider. When RMPOUT voltage is above the trip voltage at
RMPIN− pin, the PWM latch is set. GATEL becomes low, and GATEH becomes high after the non-overlap time.
If the negative slope is used, RMPIN− pin of the phase IC should be connected to RMPOUT pin of the control IC
and RMPIN+ pin should be connected to the resistor divider. When RMPOUT voltage is below the trip voltage at
RMPIN− pin, the PWM latch is set. GATEL becomes low, and GATEH becomes high after the non-overlap time.
It is best to use the VBIAS voltage as the reference for the resistor dividers because the oscillator ramp
magnitude from the control IC will track the VBIAS voltage. It is best to avoid the peak and valley of the oscillator
ramp for better noise immunity. Determine the ratio of the programming resistors corresponding to the desired
switching frequencies and phase numbers. If the resistor R
determined as:
Page 32 of 47
V
R
R
HOTSET
HOTSET2
PHASEx2
=
=
=
4.73*10
RA
R
V
HOTSET1
BIAS
PHASEx
1
−
RA
−
−
3
∗
V
∗
*T
PHASEx
V
HOTSET
R
J
HOTSET
PHASEx1
PHASE1
+
HOTSET1
1.241
HOTSET1
and R
is pre−selected, R
PHASE2
and R
HOTSET2
PHASEx1
HOTSET2
is pre-selected, the resistor R
can be calculated as follows.
J
IR3084U
(ºC) of phase IC.
(21)
(22)
(23)
9/14/2005
PHASEx2
is