ISL6310EVAL1Z Intersil, ISL6310EVAL1Z Datasheet - Page 13

• 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: -

If the R-C network components are selected such that the
R-C time constant matches the inductor L/DCR time
constant, then V
drops across the individual DCRs, multiplied by a gain. As
Equation 8 shows, V
total output current, I
By simply adjusting the value of R
to any level, giving the converter the right amount of droop at
all load currents. It may also be necessary to compensate for
any changes in DCR due to temperature. These changes
cause the load line to be skewed, and cause the R-C time
constant to not match the L/DCR time constant. If this
becomes a problem a simple negative temperature
coefficient resistor network can be used in the place of
R
temperature.
Output Voltage Offset Programming
The ISL6310 allows the designer to accurately adjust the offset
voltage by connecting a resistor, R
VCC or GND. When R
VCC, the voltage across it is regulated to 1.5V. This causes a
proportional current (I
the FB pin. If R
it is regulated to 0.5V, and I
the OFS pin. The offset current flowing through the resistor
between VDIFF and FB will generate the desired offset voltage
which is equal to the product (I
shown in Figures 8 and 9.
V
COMP
DROOP
V
ISL6310
DROOP
+
-
to compensate for the rise in DCR due to
FIGURE 7. DCR SENSING CONFIGURATION
=
PHASE1
PHASE2
DROOP
R
-------------------- - I
ICOMP
COMP
ISUM
R
IREF
OFS
S
DROOP
is connected to ground, the voltage across
⋅
OFS
DROOP
OUT
OUT
OFS
C
is equal to the sum of the voltage
) to flow into the OFS pin and out of
.
SUM
⋅
(OPTIONAL)
OFS
C
is connected between OFS and
DCR
COMP
is therefore proportional to the
13
R
OFS
S
flows into the FB pin and out of
OFS
R
R
S
x R
S
COMP
, the load line can be set
, from the OFS pin to
1
I
I
L2
). These functions are
L1
INDUCTOR
INDUCTOR
L
L
V
L
(s)
DCR
DCR
-
(EQ. 8)
C
I
OUT
V
OUT
OUT
ISL6310
Once the desired output offset voltage has been determined,
use the following formulas to set R
For Positive Offset (connect R
For Negative Offset (connect R
R
R
OFS
OFS
V
R
V
R
FIGURE 8. POSITIVE OFFSET OUTPUT VOLTAGE
FIGURE 9. NEGATIVE OFFSET OUTPUT VOLTAGE
OFS
OFS
OFS
OFS
+
-
+
-
VDIFF
VDIFF
VCC
=
=
I
--------------------------
V
--------------------------
V
OFS
GND
R
R
I
0.5 R
1.5 R
OFS
OFFSET
OFFSET
1
1
OFS
OFS
FB
FB
⋅
⋅
PROGRAMMING
PROGRAMMING
1
1
ISL6310
ISL6310
VREF
VREF
OFS
OFS
OFS
to GND):
to VCC):
:
E/A
GND
E/A
GND
+
+
-
-
0.5V
0.5V
August 7, 2008
VCC
VCC
(EQ. 10)
FN9209.4
(EQ. 9)
+
+
-
-
1.5V
1.5V