IR3502BMPBF International Rectifier, IR3502BMPBF Datasheet - Page 30

• Manufacturer Part Number: IR3502BMPBF
• Description: The IR3502B control IC combined with an XPHASE3 Phase IC provides a full featured and flexible way to implement a complete VR11.0 and VR11.1 power solution.
• Manufacturer: International Rectifier

Specifications of IR3502BMPBF

• Package: 32-Lead MLPQ
• Circuit: X-Phase Control IC
• Switch Freq (khz): 250kHz to 1.5MHz
• Pbf: PbF Option Available

DESIGN EXAMPLE – HIGH FREQUENCY CONVERTER (FIG. 20)
SPECIFICATIONS
Input Voltage: V
DAC Voltage: V
No Load Output Voltage Offset: V
Continuous Output Current: I
Maximum DC Output Current: I
Current Report Gain =0.95 V represents I
Output Impedance: R
Soft Start Delay Time: TD1=0-5ms
Soft Start Time: TD2=0.05ms-10ms
VID Sample Delay Time: TD3=0.05-3ms
VID Rise Time: TD4=0-3.5ms
VR Ready Delay Time: TD5=0.05ms-3ms
Maximum Over Current Delay Time: t
Dynamic VID Up-Slope Slew Rate: SR
Over Temperature Threshold: T
POWER STAGE
Phase Number: n=5
Switching Frequency: f
Output Inductors: L=70 nH, R
Output Capacitors: Ceramic: C=22uF, Number N
IR3502B EXTERNAL COMPONENTS
Oscillator Resistor Rosc
Once the switching frequency is chosen, R
For a switching frequency of 700kHz per phase, choose R
Soft Start Capacitor C
Determine the soft start capacitor to meet the specifications of the delay time.
Choose C
The soft start time is
The VID sample delay time is
VID rise time is
TD
TD
TD
3
1
2



C
C
C
SS
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SS
SS
SS/DEL
/
DEL
/
I
I
DEL
/
CHG
DEL
CHG
*
I
DAC
*
3 (
I
=12 V
=0.1uF. The soft start delay time is
CHG
1
1 *
2 .
4 .
SP: C=220uF, Number N
=1.2 V
1 .

1
O

4 .

=0.8 mΩ
SW
SS/DEL
0

. 0
1 .
52
1
= 700 kHz
52
* 1
) 1 .
*
5 .
OTDC
10
5 .
L
10

=0.35 mΩ (Including solder resistance)
*
OMAX
*

MAX
. 0
10

6
10
6
52
O_NLOFST
* 1
=110 A
1 *

1 *

=100 ºC
5 .
6
10
6
=140 A
4 .
OCDEL
1 .
*

up
10
6


=10mV/us
*

OMAX
. 2
0
6
2
7 .
=10 mV
OSC
<2.5ms
1 .
67
sp
mS

=2
mS
. 1
can be determined from the curve in Figure 18 of this data sheet.
c
33
=50
mS
OSC
= 17.4 kΩ. The reference current is given by 30uA.
IR3502B
V3.2