Datasheet

Performance Characteristics

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Trace 1: Input Voltage, at 30VDC. Volts/div = 20.0V Trace 2: Trace 1: VCC pin with VIN = 30VDC, Load = 4.5A Volts/div

Output Voltage, at full load. Volts/div = 2.0V Trace 3: Output = 5.0V Trace 2: VIN approaching 30VDC Volts/div = 20.0V

Current, at full load. Amps/div = 2.0A Horizontal Resolution Horizontal Resolution = 2.0ms/div

= 1.0ms/div

Figure 5. Typical Turn-on Waveforms at Full Load Figure 6. Initial Ramp-up of the Vcc Pin to 7.7V

Through the Internal Regulator

9.2 Load Step Response

Figure 7 shows the load step response at Vin = 30VDC for an instantaneous load change from 5% to full

load. The input voltage, output voltage and output current are shown.

9.3 Ripple Voltage and Ripple Current

Figure 8 shows the output ripple voltage, the output ripple current and the input ripple current relative to

the LM5020 gate drive.

Trace 1: Input Voltage, at 30VDC Volts/div = 20.0V Trace 2: Trace 1: Q1 gate drive at Vin = 48VDC Volts/div = 20.0V

Output Voltage, at 3.3VDC Volts/div = 2.0V Trace 3: Load Trace 2: Output ripple voltage Volts/div = 100mV Trace 3:

changing from 0.23A to 4.5A instantaneously Amps/div = Output ripple current Amps/div = 20.0mA Trace 4: Input

2.0A Horizontal Resolution = 1.0ms/div ripple current Amps/div = 100mA Horizontal Resolution =

2.0µs/div

Figure 7. Load Step Response at Vin = 30VDC for an Figure 8. Output Ripple Voltage, Output Ripple

Instantaneous Load Change from 5% to Full Load Current, and Input Ripple Current

AN-1314 LM5020 Evaluation Board SNVA082B–March 2004–Revised May 2013

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