isl8120 Intersil Corporation, isl8120 Datasheet - Page 32

• Manufacturer Part Number: isl8120
• Description: Dual/n-phase Buck Pwm Controller With Integrated Drivers
• Manufacturer: Intersil Corporation

Internal Reference and System Accuracy
The internal reference is set to 0.6V. Including bandgap
variation and offset of differential and error amplifiers, it has
an accuracy of ±0.6% over commercial temperature range,
and 0.9% over industrial temperature range. While the
remote sense is not used, its offset (V
included in the tolerance calculation. Equations 9 and 10
show the worst case of system accuracy calculation.
V
in the loop, the differential amplifier’s input impedance
(R
and can be neglected when R
precision setpoint, R
resistors.
Figure 25 shows the tolerance of various output voltage
regulation for 1%, 0.5%, and 0.1% feedback resistor
dividers. Note that the farther the output voltage setpoint
away from the internal reference voltage, the larger the
tolerance; the lower the resistor tolerance (R%), the tighter
the regulation.
Intersil products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without
notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be accurate and
reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result
from its use. No license is granted by implication or otherwise under any patent or patent rights of Intersil or its subsidiaries.
OS_DA
%min
DIF
R
OSMAX
) is typically 500kΩ with a tolerance of 20% (R
=
should set to zero when the differential amplifier is
(
Vref
=
⋅
---------------------------------------------------------------------------------------------------- -
-----------------------------------------
R
All Intersil U.S. products are manufactured, assembled and tested utilizing ISO9000 quality systems.
(
OS
1 Ref%
–
⋅
Intersil Corporation’s quality certifications can be viewed at www.intersil.com/design/quality
(
OS
1
1
+
For information regarding Intersil Corporation and its products, see www.intersil.com
can be scaled by two paralleled
R%
)
–
V
)
32
OS_DA
+
OS
--------------------------------------------------- -
R
1
DIF
is less than 100Ω. To set a
)
⋅
⋅
(
⎛
⎜
⎝
OS_DA
1
1
1
+
+
R
R
--------------------------------------- -
DIF
FB
R
) should be
%
OSMAX
⋅
(
)
1 R%
–
DIF
(EQ. 9)
)
%)
⎞
⎟
⎠
ISL8120
%max
FIGURE 25. OUTPUT REGULATION WITH DIFFERENT
R
-0.5
-1.0
-1.5
-2.0
-2.5
2.5
2.0
1.5
1.0
0.0
0.5
OSMIN
=
0.5
(
Vref
=
1.0
---------------------------------------------------------------------------------------------- -
-------------------------------------- -
R
⋅
RESISTOR TOLERANCE FOR Ref% =
OS
(
1 Ref%
1.5
–
⋅
(
1
1 R
OUTPUT VOLTAGE (V)
– %
2.0
)
–
)
+
V
2.5
-------------------------------------------------
R
OS_DA
1
DIF
3.0
⋅
(
)
1 R
⋅
1
–
⎛
⎜
⎝
1
3.5
DIF
+
R
--------------------------------------- -
%
FB
4.0
R
)
R%=1%
0.5%
⋅
OSMIN
0.5%
0.1%
0.1%
(
1%
1 R%
March 28, 2008
–
4.5
(EQ. 10)
±
0.6%
FN6641.0
5.0
)
⎞
⎟
⎠