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DEMO MANUAL DC1624A
qUick stArt proceDUre
Demonstration circuit DC1624A can be easily to set up to
evaluate the performance of the LTC4225-1/LTC4225-2.
Refer to the Figure 1 for proper measurement equipment
setup and follow the procedure below.
The DC1624A test includes independent tests of the
LTC4225 Hot Swap functionality, ideal diode functional-
ity and two power rails prioritizer functionality with the
channel 1 highest priority.
HOT SWAP FUNCTIONALITY TEST
This test is identical for each 12V rail and is performed
in the three steps by the measuring of the transient’s
parameters in the different operation modes.
The first step is a power-up without any additional load.
The second step is the current limit operation after suc-
cessful power-up transient. The third step is a power-up
with a shorted output.
Initially install the jumper heads in the following positions:
ON1_SEL and ON2_SEL in position OFF;
EN1_SEL and EN2_SEL in position LOW.
First Step
Connect a 12V power supply to the board input turrets
IN1 (IN2) and GND. Do not load the output. Place current
probe on the 12V supply and voltage probes on the OUT1
(OUT2) turret.
Provide ON1 (ON2) signal at the ON1 (ON2) pin by mov-
ing the ON1_SEL (ON2_SEL) jumper header from OFF
position to the ON position. Observe the transient. The
output voltage rise time should be in the range of 12ms
to 29ms.
PWRGD1
(
PWRGD2
) green LED should be lit.
Turn off the rail using the ON1_SEL (ON2_SEL) jumper.
Second Step
Initially adjust an electronic resistive load to 10Ω to 12Ω
and connect it to the OUT1 (OUT2) turret and GND. Turn
on the rail and slowly increase load current up to the circuit
breaker threshold level. The current limit range should be
from 11.5A to 13.3A. Turn off the rail using the ON1_SEL
(ON2_SEL) jumper.
Third Step
Short the output to ground with a wire. Place the current
probe on this wire. Turn on the rail and record the current
shape. The maximum current should be in the (13.6A to
18.9A) range. The LTC4225-1 latches off after overcurrent
condition, but the LTC4225-2 automatically retries after
200ms to 450ms.
IDEAL DIODE FUNCTIONALITY TEST
Use an individual 12V power supply for each rail; connect
the two outputs together at a common load. Adjust each
input voltage to 12V with maximum possible accuracy.
In this test, both rails are active and small variations in
the input voltage will force one channel off and the other
channel on.
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