ISL6559EVAL2 Intersil, ISL6559EVAL2 Datasheet - Page 5

• Manufacturer Part Number: ISL6559EVAL2
• Description: EVALUATION BOARD 2 ISL6559
• Manufacturer: Intersil

Specifications of ISL6559EVAL2

• Main Purpose: Special Purpose DC/DC, VRM Supply
• Outputs And Type: 1, Non-Isolated
• Power - Output: 67.6W
• Voltage - Output: 1.3V
• Current - Output: 52A
• Voltage - Input: 5V, 12V
• Regulator Topology: Buck
• Frequency - Switching: 250kHz
• Board Type: Fully Populated
• Utilized Ic / Part: HIP6601, ISL6559
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

1.35V
1.55V
1.35V
1.55V
Figure 7 shows the converter returning to a DAC level of
1.550V after the VID3 and VID1 states are returned to
ground. Again, the converter is loaded at 26A during the
DAC change.
Efficiency
The efficiency of the ISL6559EVAL2 board, loaded from 5 to
55A, is plotted in Figure 8. Measurements were performed at
room temperature and taken at thermal equilibrium with NO
AIR FLOW. The design exceeds the AMD Hammer Desktop
minimum requirements of 50% efficiency under minimum
loading and 80% efficiency at maximum loading even
without forced airflow. The maximum allowed airflow per the
desktop specification is 100LFM and will only enhance the
converter performance if available.
0V
0V
0V
0V
FIGURE 6. VID-ON-THE-FLY TRANSITION FROM 1.55V TO
FIGURE 7. VID-ON-THE-FLY TRANSITION FROM 1.30V TO
1.30V
1.55V
50µs/DIV
50µs/DIV
5
VID4, 5V/DIV
PGOOD, 2V/DIV
VCORE, 200mV/DIV
VCORE, 100mV/DIV
VID5, 5V/DIV
PGOOD, 10V/DIV
Application Note 1137
Thermal Performance
Figure 9 shows the laboratory measured upper and lower
MOSFET temperatures versus load current. The
measurements were performed at room temperature and
taken at thermal equilibrium with NO AIR FLOW.
Figure 10 shows the individual channel output inductor and
HIP6601B driver temperatures over the same conditions as
the MOSFETs.
FIGURE 10. INDUCTOR/DRIVER TEMPERATURE vs LOAD
FIGURE 9. MOSFET TEMPERATURE vs LOAD CURRENT
73
70
82
79
76
85
5
52
61
43
34
25
70
45
55
35
25
75
65
FIGURE 8. EFFICIENCY vs LOAD CURRENT
5
5
Q1
Q2
Q3
Q4
Q5
Q6
D1
D2
D3
L1
L2
L3
CURRENT
15
15
15
LOAD CURRENT (A)
LOAD CURRENT (A)
LOAD CURRENT (A)
NO AIR FLOW
25
25
25
NO AIR FLOW
NO AIR FLOW
35
35
35
45
45
45
55
55
55