ISL6420BEVAL2Z Intersil, ISL6420BEVAL2Z Datasheet - Page 14

• Manufacturer Part Number: ISL6420BEVAL2Z
• Description: EVAL BOARD 2 FOR ISL6420B
• Manufacturer: Intersil

Specifications of ISL6420BEVAL2Z

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

A small ceramic capacitor should be placed in parallel
with R
the presence of switching noise on the input voltage.
Voltage Margining
The ISL6420B has a voltage margining mode that can
be used for system testing. The voltage margining
percentage is resistor selectable up to ±10%. The
voltage margining mode can be enabled by connecting
a margining set resistor from VMSET pin to ground and
using the control pins GPIO1/2 to toggle between
positive and negative margining (Refer to Table 3).
With voltage margining enabled, the VMSET resistor to
ground will set a current, which is switched to the FB
pin. The current will be equal to 2.468V divided by the
value of the external resistor tied to the VMSET pin.
Use a resistor in the range of 150kΩ to 400kΩ for
VMSET resistor.
The power supply output increases when GPIO2 is
HIGH and decreases when GPIO1 is HIGH. The amount
that the output voltage of the power supply changes
with voltage margining, will be equal to 2.468V x the
ratio of the external feedback resistor and the external
resistor tied to VMSET. Figure 11 shows the positive
and negative margining for a 3.3V output, using a
20.5kΩ feedback resistor and using various VMSET
resistor values.
FIGURE 11. VOLTAGE MARGINING vs. VMSET
I
Δ
1. The maximum r
2. Determine
VM
V
VM
3.7
3.6
3.5
3.4
3.3
3.2
3.1
3.0
2.9
2.8
temperature.
where ΔI is the output inductor ripple current.
=
150 175 200 225 250 275 300 325 350 375 400
OCSET
=
----------------------- -
R
2.468V
VMSET
2.468V
RESISTANCE
to smooth the voltage across R
----------------------- -
R
I
OC
VMSET
R
FB
for I
DS(ON)
OC
RVMSET (kΩ)
>
14
I
OUT MAX
at the highest junction
(
)
+
(
ΔI
) 2 ⁄
,
OCSET
(EQ. 2)
(EQ. 3)
in
ISL6420B
V
V
VIN = 12V, V
V
IN
IN
IN
FIGURE 13. PGOOD DELAY
= 12V, V
= 12V, V
= 12V, V
FIGURE 12A.
FIGURE 12B.
OUT
OUT
OUT
OUT
= 3.3V, NO LOAD
= 3.3V, NO LOAD
= 3.3V, NO LOAD
= 3.3V, I
OUT
= 10A
December 4, 2009
FN6901.1