ir3084a International Rectifier Corp., ir3084a Datasheet - Page 38

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

IR3086 PHASE IC COMPONENTS
PWM Ramp Resistor R
Set the PWM ramp magnitude V
calculate the resistor R
Inductor Current Sensing Capacitor C
Choose C
The bias currents of CSIN+ and CSIN
Equation (20);
Over Temperature Setting Resistors R
Use central over temperature setting and set the temperature threshold at 115 ºC, which corresponds the IC die
temperature of 116 ºC. Calculate the HOTSET threshold voltage corresponding to the temperature thresholds
using Equations (21) and (22);
Page 38 of 45
V
R
R
R
R
CS+
HOTSET
PWMRMP
CS
HOTSET
CS
−
+
=47nF and calculate R
=
=
2
. 0
L
=
0
C
=
Choose a standard resistor value, R
=
=
25
4 .
. 4
CS
R
V
R
12
73
+
∗
L
V
IN
HOTSET
PWMRMP
R
BIAS
*
∗
=
RAMP
∗
CS
10
400*10
220
f
+
−
SW
−
1
=
3
V
∗
and Capacitor C
*
*
∗
V
HOTSET
. 0
using Equation (18);
T
0
10
C
HOTSET
4 .
25
J
PWMRMP
3
47
PWMRMP
−
+
∗
CS+
9
∗
. 1
*
220*10
/(0.47
10
10
241
=
CS+
using Equation (19);
0 .
HOTSET1
−
∗
20
9
*
to 0.8V. Choose 220pF for the PWM ramp capacitor C
=
are 0.25uA and 0.4uA respectively. Calculate resistor R
[ln(V
*
10
and Resistors R
6
*
10
. 4
−
8 .
12
10
3
RAMP
73
−
−
=
∗
3
3
and R
IN
. 1
)
*
[ln(12
6
∗
10
=
79
1.30
2 .
−
. 1
V
PWMRMP
10.0k
V
k
−
79
3
Ω
O
DAC
HOTSET2
∗
−
,
=
116
)
1.30)
. 7
−
CS+
14
=15.8k
+
ln(V
. 1
choose R
k
−
and R
Ω
241
IN
ln(12
−
=
CS
V
. 1
DAC
−
CS
79
¤
1.30
¥
V
−
= 6.19k
, choose R
V
−
PWMRMP
0.8)]
)]
=
HOTSET1
15.8k
IR3084A
10/30/2006
=20.0k
PWMRMP
,
CS
¥
using
and