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7

iP2002

V

SW

P

GND

PRDY

ENABLE

V

DD

S

GND

A

A

DC

V

Average

Input

Voltage

Average

Input

Current

Average Output

Current

Averaging

Circuit

V

Average

Output

Voltage

DC

V

Average

VDD

Voltage

A

Average

VDD

Current

iP2001

P

P

P

P

V

IN

PWM

t

d(on)

t

d(off)

PWM

V

SW

90%

10%

90%

10%

Fig 8. Power Loss Test Circuit

Fig 9. Timing Diagram

iP2002

Average

Output

Voltage

(V

Example 2) Adjusting for SOA Temperature:

(Fig. 3)

Normalized SOA Temperature for input voltage

(Fig. 4)

Normalized SOA Temperature for output voltage

(Fig. 5)

Normalized SOA Temperature for frequency

(Fig. 6)

Normalized SOA Temperature for inductor value

T

Assuming T

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

0

10

20

30

40

5060708090

100

110

120

0

2

4

6

8

10

12

14

16

18

20

22

24

26

28

30

32

0

10

20

30

40

5060708090

100

110

120

PCB Temperature (ºC)

Safe

Operating

Area

L = 0.30uH

Case Temperature (ºC)

Unadjusted SOA Current

Adjusted SOA Current