ISL6310EVAL1Z Intersil, ISL6310EVAL1Z Datasheet - Page 8

• Manufacturer Part Number: ISL6310EVAL1Z
• Description: EVALUATION BOARD FOR ISL6310
• Manufacturer: Intersil

Specifications of ISL6310EVAL1Z

• Main Purpose: DC/DC, Step Down
• Outputs And Type: 1, Non-Isolated
• Voltage - Output: 1.5V
• Current - Output: 60A
• Voltage - Input: 5 ~ 12V
• Regulator Topology: Buck
• Frequency - Switching: 400kHz
• Board Type: Fully Populated
• Utilized Ic / Part: ISL6310
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Power - Output: -

The efficiency for V
efficiency peaks just below 89% at 35A for the PVCC = 12V
case and then levels off steadily to approximately 87% at
60A, while for the PVCC = 5V, efficiency peaks at around
90% at 20A and then falls down to approximately 86% at
60A. The use of air flow could improve the efficiency across
the load range and keeps the components cooler leading to
better reliability and longer component lives.
Modifications
Adjusting the Output Voltage
The output voltage can be adjusted by changing the 2 bit
inputs (REF1, REF0) of internal DAC (externally connected
with a resistor to REF). Please consult the data sheet for the
available voltage ranges and the required settings.
92
90
88
86
84
82
80
78
76
74
72
70
90
88
86
84
82
80
78
76
74
72
70
0
0
FIGURE 14. EFFICIENCY vs LOAD CURRENT
FIGURE 15. EFFICIENCY vs LOAD CURRENT
5
5
10
10
PVCC = 12V
15
15
OUT
PVCC = 12V
20
20
= 1.8V is plotted in Figure 15. The
LOAD CURRENT ( A )
LOAD CURRENT ( A )
25
25
8
30
30
35
35
PVCC = 5V
40
40
V
V
Fsw = 400kHz
Fsw = 400kHz
OUT
OUT
PVCC = 5V
45
45
= 1.8V
= 1.5V
50
50
Application Note 1197
55
55
60
60
The offset pin (OFS) allows for small-range (less than
100mV), positive or negative, offsetting of the output voltage.
The board is shipped with R90 equal to 0Ω and R82 is not
populated to provide an output voltage equal to the internal
DAC setting. Should an output voltage setting outside the
normal range provided via the internal DAC be required, a
separate resistor divider connected from the load output
terminals to VSEN pin as shown in Figure 16 is needed.
Use the following relationships to calculate the value of the
resistors based on the known parameters.
Choose a value for RL (for example 300Ω)
Choose a value of VREF that meets the following condition
Calculate the value of the resistor R
Example:
V
R
VREF
R
OUT
L
H
FIGURE 16. ADJUSTING V
+
=
R
VREF
R
VREF
R
-----------------------------------------------------
H
= 2.1V
R
≥
H
L
L
≤
VOUT 0.8V
R1
⋅
C2
=
500Ω
=
(
VOUT REF
≥
300Ω
------------------------------------------------------- -
300Ω
=
REF
2.1V 0.8V
RANGE
COMP
–
1.5V
C1
FB
⋅
–
–
(
1.5V
2.1V 1.5V
4
5
)
–
6
≥
1.3V
OUT
ISL6310
7
)
OUTSIDE THE REF (DAC)
=
RL = R
120Ω
H
8
81
RH = R
December 12, 2006
90
VOUT+
VOUT-
AN1197.1
(EQ. 1)
(EQ. 2)
(EQ. 3)
(EQ. 4)