ISL6263AIRZ Intersil, ISL6263AIRZ Datasheet - Page 16

• Manufacturer Part Number: ISL6263AIRZ
• Description: IC PWN CTRLR SYNC BUCK 32QFN
• Manufacturer: Intersil

Specifications of ISL6263AIRZ

• Applications: Converter, Intel IMVP-6
• Voltage - Input: 5 V ~ 25 V
• Number Of Outputs: 1
• Voltage - Output: 0.41 V ~ 1.29 V
• Operating Temperature: -40°C ~ 100°C
• Mounting Type: Surface Mount
• Package / Case: 32-VFQFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

The current sensing traces should be routed directly to the
inductor pads for accurate DCR voltage drop measurement.
However, due to layout imperfection, the calculated R
may still need slight adjustment to achieve optimum load line
slope. It is recommended to adjust R
has achieved thermal equilibrium at full load. For example, if
the maximum load current is 20A, one should apply a 20A
load current and look for 160mV output voltage droop. If the
voltage droop is 155mV, the new value of R
calculated in Equation 17:
For the best accuracy, the effective resistance on the DFB
and VSUM pins should be identical so that the bias current
of the droop amplifier does not cause an offset voltage.
Dynamic Droop Capacitor Design Using DCR
Sensing
Figure 10 shows the desired waveforms during load
transient response. V
I
V
of output inductor, output capacitor, compensator design,
and the design of droop capacitor C
If C
an excellent representation of the inductor current. Given the
correct C
I
waveform of the inductor current and worsens the transient
response. Figure 11 shows the transient response when C
is too small allowing V
load transient. Figure 12 shows the transient response when
C
value.
R
core
CORE
CCGFX
N
DRP2new
N
is too large. V
as close as possible. The transient response of
is designed correctly, the voltage V
, if not, its voltage will be distorted from the actual
is determined by several factors, namely the choice
N
design, V
=
160mV
-------------------
155mV
FIGURE 9. EQUIVALENT MODEL FOR DROOP CIRCUIT USING DISCRETE RESISTOR CURRENT SENSING
CCGFX
CCGFX
⋅
CCGFX
(
CCGFX
R
DRP1
takes too long to droop to its final
has the best chance of tracking
16
needs to follow the change in
+
to sag excessively during the
R
DRP2
OCP
N
DRP2
−
+
+
−
.
) R
–
10µA
DROOP
DRP1
after the system
DRP2
DROOP
-V
is
+
−
O
(EQ. 17)
DROOP
will be
OCSET
DRP2
VSUM
VDD
DFB
VO
ISL6263A
N
R
OCSET
FIGURE 10. DESIRED LOAD TRANSIENT RESPONSE
FIGURE 12. LOAD TRANSIENT RESPONSE WHEN C
FIGURE 11. LOAD TRANSIENT RESPONSE WHEN C
V
V
V
core
core
core
WAVEFORMS
SMALL
LARGE
Δ
V
core
R
S
=
V
V
V
i
i
i
core
core
core
Δ
core
core
core
I
core
V
RSNS
×
R
droop
Δ
Δ
V
I
core
core
N
N
July 8, 2010
IS TOO
IS TOO
FN9284.3