PD-60325

iP2005APbF

Calculating SOA Temperature:

(Figure 3)

SOA temperature adjustment for input voltage

≈ -1.2ºC

(Figure 4)

SOA temperature adjustment for output voltage

≈ 0.0ºC

(Figure 5)

SOA temperature adjustment for output inductor

≈ 0.6 ºC

(Figure 6)

SOA temperature adjustment for switch frequency

≈ -3.5 ºC

T

Assuming T

The following example shows how the SOA current is adjusted for T

1. Draw a line from Case Temperature axis to the PCB Temperature axis.

2. Draw a vertical line from the T

3. Draw a horizontal line from the intersection of the vertical line with the SOA curve to the

Y-axis (Output Current). The point at which the horizontal line meets the Y-axis is the

SOA continuous current.

4. Draw a new vertical line from the T

temperature from the original T

5. Draw a horizontal line from the intersection of the new vertical line with the SOA curve to

the Y-axis (Output Current). The point at which the horizontal line meets the Y-axis is

the new SOA continuous current.

The SOA adjustment indicates the part is still allowed to run at a continuous current of 36A.

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2/8/2008

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