IR3082A International Rectifier Corp., IR3082A Datasheet - Page 27

• Manufacturer Part Number: IR3082A
• Description: 9.6v Amd Xphasetm Control Ic
• Manufacturer: International Rectifier Corp.

IR3086A EXTERNAL COMPONENTS
PWM Ramp Resistor R
Set PWM ramp magnitude V
resistor R
Inductor Current Sensing Capacitor C
Choose C
Choose
R
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.
Phase Delay Timing Resistors R
The phase delay resistor ratios for phases 1 to 5 at 600kHz of switching frequencies are RAPHASE1=0.646,
RAPHASE2=0.400, RAPHASE3=0.158, RAPHASE4=0.291 and RAPHASE5=0.561starting from down-slope. Pre-
select RPHASE11=RPHASE21=RPHASE31=RPHASE41=RPHASE51= RPHASE61=20k
R
Bootstrap Capacitor C
Choose C
Decoupling Capacitors for Phase IC and Power Stage
Choose C
V
R
R
R
R
R
CS
CS-
HOTSET
PHASE22
PWMRMP
HOTSET
CS
PHASE
12
˜
,
600
12
2
L
C
. 0
0
Page 27 of 33
R
CS
25
4 .
˜
R
CS
. 4
PWMRMP
10
=13.3
CS+
1
BST
VCC
V
R
L
73
V

IN
˜
RA
HOTSET
3
R
BIAS
RA
˜
˜
=47nF and calculate R
˜
=0.1uF
=0.1uF, C
100
CS
10
11
220
PHASE
f
SW
PHASE

5 .
1
3
˜
V
˜
˜
,
10
˜
k
˜
V
1
10
C
HOTSET
:
. 0
T
0
HOTSET
1
PWMRMP
47
J
25
4 .
PHASE32
12
. The bias currents of CSIN+ and CSIN- are 0.25uA and 0.4uA respectively. Calculate resistor
˜
9

R
/(
˜
˜
. 1
10
˜
PHASE
BST
VCCL
[ln(
RAMP
. 0
10
241
. 1
42
˜
0 .
12
9
[ln(
30
11
20
˜
˜
=0.1uF
10
PWMRMP
10
6
=3.74

and Capacitor C
V
8 .
˜
. 4
. 1
10
3
IN
1
3
73

30
)

. 0
3

. 1
PHASE1
˜
. 0
)
. 7
˜
646
. 1
V
10
79
V

CS+,
11
646
DAC
19
79
O
ln(
=0.8V. Choose 100pF for PWM ramp capacitor C
2 .
3
k
)
:
12
˜
k
˜
CS+
116

PHASE42
HOTSET1
20
:
. 7
, choose R
ln(
and R

14
˜
. 1
10

V
and Resistors R
30
. 1
k
IN
:
3
241
RAMP


PHASE2
=8.2
V
0
and R
36
DAC
8 .
5 .
)]
. 1
CS-
k

79
:
V
=7.15k
17
HOTSET2
V
PWMRMP
.
, choose R
k 9
PHASE52
:
CS+
)]
, choose R
and R
=25.5
HOTSET1
CS-
PWMRMP
=20.0k
=18.2k
PWMRMP
05/02/2006
IR3082A
, and calculate the