LM5020EVAL National Semiconductor, LM5020EVAL Datasheet - Page 3

• Manufacturer Part Number: LM5020EVAL
• Description: EVALUATION BOARD FOR LM5020
• Manufacturer: National Semiconductor
• Series: PowerWise®r

Specifications of LM5020EVAL

• Main Purpose: DC/DC, Step Down
• Outputs And Type: 1, Isolated
• Voltage - Output: 3.3V
• Current - Output: 4.5A
• Voltage - Input: 30 ~ 75V
• Regulator Topology: Buck
• Board Type: Fully Populated
• Utilized Ic / Part: LM5020
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Power - Output: -
• Frequency - Switching: -
• Other names: *LM5020EVAL

Performance Characteristics
TURN-ON WAVEFORMS
When applying power to the LM5020 evaluation board a
certain sequence of events must occur. The soft-start feature
allows for a minimal output voltage for a short time until the
feedback loop can stabilize without overshoot. Figure 1,
Figure 2 and Figure 3 show typical turn-on waveforms at no
load, 5% load, and at full load. Input voltage, output voltage
and output current are shown.
Figure 4 shows the initial ramp-up of the Vcc pin to 7.7 volts
through the internal regulator. The auxiliary winding starts to
supply a higher voltage as the output voltage rises. The
resulting second ramp is shown following the soft-start delay.
This sequence is nearly identical for all loads and input
voltages.
Trace 1: Input Voltage, at 30VDC.
Volts/div = 20.0V
Trace 2: Output Voltage, no load.
Volts/div = 2.0V
Trace 3: Output Current, no load.
Amps/div = 100mA
Horizontal Resolution = 1.0ms/div
FIGURE 1.
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Trace 1: Input Voltage, at 30VDC.
Volts/div = 20.0V
Trace 2: Output Voltage, at 5% load.
Volts/div = 2.0V
Trace 3: Output Current, at 5% load.
Amps/div = 100mA
Horizontal Resolution = 1.0ms/div
FIGURE 2.
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