IR3513Z International Rectifier Corp., IR3513Z Datasheet - Page 26

• Manufacturer Part Number: IR3513Z
• Description: Xphase3tm Pol Control Ic
• Manufacturer: International Rectifier Corp.

DESIGN PROCEDURES
IR3513Z EXTERNAL COMPONENTS
Oscillator Resistor Rosc
The oscillator of IR3513Z generates square-wave pulses to synchronize the phase ICs. The switching frequency of
the each phase converter equals the PHSOUT frequency, which is set by the external resistor R
curve in Figure 16. The CLKOUT frequency equals the switching frequency multiplied by the phase number.
Soft Start Capacitor C
The C
delay time and over-current fault latch delay time after VR ready. These parameters can be calculated with the
following equations:
SS/DEL
Page 26
capacitor programs four different time parameters, i.e. soft start delay time, soft start time, VR ready
SS/DEL
T
T
T
T
55
50
45
40
35
30
25
20
15
10
5
ssdelay
ss
PG
OC
200
=
_
_
delay
delay
300
C
=
SS
C
=
=
Figure 16 Operational Frequency vs Rosc Resistor
400
/
DEL
I
SS
C
C
CHG
/
I
SS
SS
500
DEL
*
CHG
/
/
Vref
DEL
DEL
1 *
600
I
( *
*
4 .
CHG
I
120
=
700
CHG
. 3
IR3513 Frequency vs. ROSC Resistor
=
C
12
52
C
*
SS
800
52
Frequency (KHz)
10
SS
−
5 .
/
DEL
5 .
/
Vref
−
*
900
DEL
3
*
10
*
10
=
1 *
1000
0
−
)
C
6
8 .
−
=
6
4 .
SS
1100
C
/
52
DEL
52
SS
1200
5 .
/
5 .
DEL
*
*
120
*
10
1300
10
*
. 2
−
*
−
6
1400
6
32
10
−
3
1500
.
1600
(1)
(2)
(3)
(4)
RROSC
Nominal Spec
May 11, 2009
OSC
IR3513Z
according to the