ISL6144IVZA-T Intersil, ISL6144IVZA-T Datasheet - Page 16

• Manufacturer Part Number: ISL6144IVZA-T
• Description: IC CTRLR MOSFET HV ORING 16TSSOP
• Manufacturer: Intersil

Specifications of ISL6144IVZA-T

• Applications: Telecom/Datacom Systems
• Fet Type: N-Channel
• Number Of Outputs: 1
• Internal Switch(s): No
• Delay Time - On: 1ms
• Delay Time - Off: 250ns
• Voltage - Supply: 10 V ~ 75 V
• Operating Temperature: -40°C ~ 105°C
• Mounting Type: Surface Mount
• Package / Case: 16-TSSOP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Current - Supply: -

DC/DC Converter Power Board (not part of the
ISL6144EVAL1Z board)
The DC/DC converter board consists of two DC/DC
converters with independent input voltage rails. In reality, two
identical power supplies can be used in the test setup to
replace this board (contact Intersil Applications Engineering
if you need assistance in your test setup). This DC/DC
converter board is configured for operation at different output
voltage levels depending on the choice of DC/DC modules.
Most evaluation results are provided for a mix of +48V and
+12V input voltages. Any other voltage within the +9V to
+75V range can also be used.
Each DC/DC converter has a low r
connected in parallel to the output terminals. This MOSFET
is normally off. When turned on it simulates a short across
the output. Another MOSFET is connected at the ON/OFF
pin of the modules to simulate a slow turn-off of the module.
Single-Feed Evaluation
The ISL6144EVAL1Z is hooked up to two input power
supplies using test setup shown in Figure 16 or Figure 17.
Note that the ISL6144EVAL1Z is populated with one
FDB3632 MOSFET per feed (Nominal value of the
MOSFET’s r
1. Connect the input power supplies, auxiliary 5V power
2. Connect test equipment (Oscilloscope, DMM) to the
3. Turn-on PS1 with V
4. The forward voltage drop across the MOSFET terminals
5. For I
6. Increase the load current I
7. Turn-off V
supply, load and output capacitor to the ISL6144EVAL1Z.
signals of interest using on-board test points and scope
probe jacks.
within +9V to +75V). Turn-on the auxiliary power supply
(AUX PS powering the LED circuit) with +5V. Adjust load
current to 2A. Verify the main operational parameters
such as the 20mV forward regulation at light loads, and
gate voltage as a function of load current.
V
forward regulated voltage drop across the source-drain
“V
MOSFET on-state resistance “I
gate-source voltage is modulated as a function of load
current and MOSFET transconductance. Gate-source
voltage V
case, LED1 is off. LED2 will be RED as V
increased to above V
forward regulation cannot be maintained. The MOSFET
cannot deliver the required load current with a 20mV
constant V
pumped to V
listed above. Make sure the ISL6144 is providing gate
voltage, which is modulated based on the load current.
V
measured between (TP14-TP21).
SD1
SD2
FWD_HR
Load
(TP1-TP2) is equal to the maximum of the 20mV
is measured between (TP4-TP5), V
DS(ON)
GS1
= 2A, V
IN1
SD1
“ or the product of the load current and the
GQP
and turn-on V
(TP13 -TP17) is approximately 4V. In this
. In this case, gate voltage is fully charge-
is approximately 8mΩ at V
SD1
(10.6V nominal).
IN1
FWD_HR
is equal to V
= +48V (V
16
Load
IN2
and operation in the 20mV
and repeat the same tests
DS(ON)
Load
to 4A. Note that V
IN1
FWD_HR
* r
can be any voltage
MOSFET
DS(ON)
IN2
GS2
GS
= 20mV. The
is still off.
”.
is
= 10V).
DS1
is
ISL6144
Two-Feed Parallel Evaluation
Two Feed parallel operation verification can be performed
after completion of the single feed evaluations. Make sure
that the two Input power supplies connected to the
ISL6144EVAL1Z board are identical in voltage value.
Identical input voltages are needed to enable the two feeds
to share the load current (In real world power systems,
current sharing is most likely insured by the power
supplies/modules that have an active current sharing
feature).
Performance Tests
Performance tests can be carried out after the two feeds
have been verified and found to be operational in active,
1 + 1 redundancy (when two feeds share the load current,
current sharing is ensured by the incoming power supplies.)
These include gate turn-on at power supply start-up, fast
speed turn-off (in case of fast dropping input rail), slow
speed turn-off (in response to slow dropping input rail) and
fault detection in response to different faults.
Gate Start-Up Test
FIRST-FEED START-UP
When the first feed is turned on, as V
occurs through the body diode of the MOSFET. This only
occurs for a short time until the MOSFET gate voltage can
be charge-pumped on. This conduction is necessary for
proper operation of the ISL6144. It provides bias for the gate
1. Turn-on PS1 and PS2 in sequence (hot plugging is not
2. Adjust the load current to different values and verify that
3. At light loads, I
4. Verify the Gate voltage of both MOSFETs V
5. Both LED1 and LED2 are off when both feeds are on.
6. For I
7. Turn V
recommended). Adjust V
other. Verify the input current of both feeds to be within
acceptable current sharing accuracy (~10%). Current
sharing accuracy will be very poor at light loads and
becomes better with higher load currents.
both V
to each other. These two voltages might be different
depending on the amount of load current passing through
each of the two feeds.
ISL6144 operates in the forward regulation mode and
gate voltage is modulated as a function of load current.
When I
20mV, the charge pump increases and clamps the gate
voltage to the maximum possible charge pump voltage,
V
TP17) and V
currents.
turned off. LED2 is RED and V
around 4V to V
LED1 is RED. V
GQP
Load
.
SD1
IN2
Load
= 4A, turn-off V
back on and turn V
(TP1 to TP2) and V
*r
GS2
DS(ON)
Load
GQP
GS2
(TP14 to TP21) with different load
.
* r
has increased to V
becomes higher than the regulated
DS(ON)
IN1
IN2
and V
and note that V
IN1
SD2
is less than 20mV, the
GS1
off. V
IN1
(TP4 to TP5) are close
IN2
has increased from
rises, conduction
close to each
GS1
GQP
GS1
is now off.
.
GS2
January 6, 2011
(TP13 to
has
FN9131.6