LM5025EVAL National Semiconductor, LM5025EVAL Datasheet - Page 3

• Manufacturer Part Number: LM5025EVAL
• Description: EVALUATION BOARD FOR LM5025
• Manufacturer: National Semiconductor
• Series: PowerWise®r

Specifications of LM5025EVAL

• Main Purpose: DC/DC, Step Down
• Outputs And Type: 1, Non-Isolated
• Voltage - Output: 3.3V
• Current - Output: 30A
• Voltage - Input: 36 ~ 72V
• Regulator Topology: Buck
• Frequency - Switching: 230kHz
• Board Type: Fully Populated
• Utilized Ic / Part: LM5025
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Power - Output: -
• Other names: *LM5025EVAL; *LM5025EVAL/NOPB; LM5025EVAL

Powering Up
the wattage of the load. As you remove the connection from
the shutdown pin to ground, immediately check for 3.3 volts
at the output.
A most common occurrence, that will prove unnerving, is
when the current limit set on the source supply is insufficient
for the load. The result is similar to having the high source
impedance referred to earlier. The interaction of the source
supply folding back and the UUT going into undervoltage
shutdown will start an oscillation, or chatter, that may have
highly undesirable consequences. A quick efficiency check is
the best way to confirm that everything is operating properly.
If something is amiss you can be reasonably sure that it will
(Continued)
Typical Evaluation Setup
3
affect the efficiency adversely. Few parameters can be in-
correct in a switching power supply without creating losses
and potentially damaging heat.
Over Current Protection
The evaluation board is configured with delayed hiccup over-
current protection. In the event of an output overload (ap-
proximately 33A) the unit will discharge the softstart capaci-
tor, which disables the power stage. After a delay the
softstart is released. The shutdown, delay and slow recharge
time of the softstart capacitor protects the unit, especially
during short circuit event where the stress is highest.
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