IR3505M International Rectifier Corp., IR3505M Datasheet - Page 14

• Manufacturer Part Number: IR3505M
• Description: Xphase3 Phase Ic
• Manufacturer: International Rectifier Corp.

Figure 7 provides an application circuit that allows adjustment to the number of phases. By populating zero ohm
jumpers, or not; the number of phases can be adjusted by diverting the daisy chain timing from a 3505 to the next
one in sequence. The effect of more or less phases on converter performance can be tested without actually
removing a 3505 or it’s MOSFETs from the printed circuit board through use of a pull-up resistor from VCCL to
the CSIN+ pin to enable de-bug mode.
Three
Phase
Two
Phase
Page 14 of 19
U0
U0
IR3500
CONTROL
IC
IR3500
CONTROL
IC
Figure 7 – Optional Phase application circuit
U1
U1
1
2
3
4
1
2
3
4
ISHARE
DACIN
LGND
PHSIN
ISHARE
DACIN
LGND
PHSIN
IR3505
PHASE
IC
IR3505
PHASE
IC
R12
open
R12
open
R13
Open
R13
Open
GATEH
BOOST
GATEH
BOOST
VCCL
VCCL
SW
SW
0 ohm
0 ohm
R11
R11
12
11
10
9
12
11
10
9
U2
U2
1
2
3
4
1
2
3
4
ISHARE
DACIN
LGND
PHSIN
ISHARE
DACIN
LGND
PHSIN
IR3505
PHASE
IC
IR3505
PHASE
IC
R22
open
R22
0 ohm
R23
Open
R23
Open
GATEH
BOOST
GATEH
BOOST
VCCL
VCCL
SW
SW
R21
0 ohm
R21
0 ohm
12
11
10
9
12
11
10
9
U3
U3
1
2
3
4
1
2
3
4
ISHARE
DACIN
LGND
PHSIN
ISHARE
DACIN
LGND
PHSIN
Sept 26
IR3505
PHASE
IC
IR3505
PHASE
IC
R32
open
R32
open
R33
Open
R33
0 ohm
GATEH
BOOST
GATEH
BOOST
VCCL
VCCL
th
IR3505
SW
SW
, 2007
12
11
10
9
12
11
10
9
R31
0 ohm
R31
open