ir3084a International Rectifier Corp., ir3084a Datasheet - Page 31

• Manufacturer Part Number: ir3084a
• Description: Xphase Tm Vr 10/11 Control Ic
• Manufacturer: International Rectifier Corp.

Combining the Over Temperature and Phase Delay Setting Resistors R
The over temperature setting resistor divider can be combined with the phase delay resistor divider to save one
resistor per phase.
Calculate the HOTSET threshold voltage V
Equation (20). If the over temperature setting voltage is lower than the phase delay setting voltage,
VBIAS*RA
between R
If the over temperature setting voltage is higher than the phase delay setting voltage, VBIAS*RA
HOTSET pin between R
R
Bootstrap Capacitor C
Depending on the duty cycle and gate drive current of the phase IC, a 0.1uF to 1uF capacitor is needed for the
bootstrap circuit.
Decoupling Capacitors for Phase IC
0.1uF 1uF decoupling capacitors are required at VCC and VCCL pins of phase ICs.
PHASEx3
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R
R
R
R
respectively. Pre-select R
PHASEx2
PHASEx3
PHASEx2
PHASEx3
PHASEx
PHASEx2
, connect RMPIN+ or RMPIN pin between R
=
=
=
=
and R
V
(RA
(V
RA
V
BIAS
HOTSET
HOTSET
PHASEx
BST
PHASEx
*(1
V
PHASEx3
PHASEx1
BIAS
V
−
−
∗
BIAS
∗
∗
RA
−
V
R
RA
V
V
V
BIAS
PHASEx1
BIAS
BIAS
respectively. Pre-select R
∗
PHASEx
HOTSET
PHASEx
(1
and R
PHASEx1
*R
−
−
−
PHASEx1
V
V
RA
)
∗
HOTSET
HOTSET
PHASEx2
V
PHASEx
,
BIAS
HOTSET
)*R
)
)
∗
and connect RMPIN+ or RMPIN
R
PHASEx1
PHASEx1
corresponding to the allowed maximum temperature from
PHASEx1,
PHASEx1
then calculate R
and R
PHASE1,
PHASEx2
R
PHASEx2
PHASE2
and connect HOTSET pin
between R
and R
and R
IR3084A
10/30/2006
PHASEx
(24)
(25)
(26)
(27)
PHASEx3,
PHASE3
PHASEx2
, connect
and