19-Nov-02

EPR-21 – 5 V, 30 W DC-DC Converter

12.3 Load Transient Response (75% to 100% Load Step)

In the figures shown below, signal averaging was used to better enable viewing the load

transient response. The oscilloscope was triggered using the load current step as a

trigger source. Since the output ripple occurs essentially at random with respect to the

load transient, contributions to the displayed trace form the output ripple will average out,

leaving the contribution only from the load step response.

Figure 26

− Output Transient Response.

50% to 75% to 50% Load Step,

36 VDC Input.

Upper Trace: Load Current, 2 A/div.

Bottom Trace: Output Voltage,

50 mV/div, 100

µs/div.

Figure 27

− Output Transient Response.

50% to 75% to 50% Load Step,

48 VDC Input.

Upper Trace: Load Current, 2 A/div.

Bottom Trace: Output Voltage,

50 mV/div, 100

µs/div.

Figure 28

− Output Transient Response.

50% to 75% to 50% Load Step,

72 VDC Input.

Upper Trace: Output Current, 2 A/div.

Bottom Trace: Output Voltage,

50 mV/div, 100

µs/div.

Page 23 of 32

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