ISL6559EVAL1 Intersil, ISL6559EVAL1 Datasheet - Page 5

• Manufacturer Part Number: ISL6559EVAL1
• Description: EVALUATION BOARD ISL6559
• Manufacturer: Intersil

Specifications of ISL6559EVAL1

• Main Purpose: Special Purpose DC/DC, VRM Supply
• Outputs And Type: 1, Non-Isolated
• Power - Output: 125W
• Voltage - Output: 1.25V
• Current - Output: 100A
• Voltage - Input: 5V, 12V
• Regulator Topology: Buck
• Frequency - Switching: 600kHz
• Board Type: Fully Populated
• Utilized Ic / Part: ISL6559, ISL6605
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

Efficiency
The efficiency of the ISL6559EVAL1 board, loaded up to
100A is plotted in Figure 8. Measurements were performed
at room temperature and taken at thermal equilibrium with
400 LFM of air and heatsink. The design exceeds the AMD
Hammer Desktop minimum requirements of 50% efficiency
under minimum loading and 80% efficiency at maximum
loading.
Additional testing was performed in a wind tunnel where we
were able to achieve a 120A constant load at 45°C ambient
and 300LFM of airflow. The board temperature was
monitored and stabilized at around 100°C.
.
Adapting Circuit Performance
Higher r
the cost curve must be tilted lower. The tradeoff for lowering
FIGURE 7. VID-ON-THE-FLY TRANSITION FROM 1.30V TO
90
85
80
75
70
65
60
55
50
FIGURE 8. VRM EFFICIENCY vs LOAD CURRENT
0
DS(ON)
10
1.55V
1.25V
MOSFETs can be employed in the design, if
20
30
40
LOAD (I)
5
50
60
70
80
Application Note 1132
90
100
cost is reduced thermal and efficiency performance of the
solution. Select an upper MOSFET with an r
than 12mΩ and keep the total gate charge below 15nC. This
combined with a lower MOSFET of no more than 7mΩ with a
total gate charge of 50nC to 70nC can provide a cost
effective and thermally acceptable solution.
Summary
The ISL6559EVAL1 is an adaptable evaluation tool which
showcases the performance of the ISL6559 and ISL6605
chip set. Designed to meet the performance requirements of
AMD’s Hammer Family Desktop microprocessors, the board
allows the user the flexibility to configure the board for
current as well as future microprocessor offerings. The
following pages provide a schematic of the board, bill of
materials and layout drawings to support implementation of
this solution.
References
Intersil documents are available on the web at
http://www.intersil.com/.
[1] ISL6559 Data Sheet, Intersil Corporation, File No.
FN9084.
[2] ISL6605 Data Sheet, Intersil Corporation, File No.
FN9091.
DS(ON)
no larger