AN-31
300
250
200
150
300
250
200
150
T
S
t
t
t
t
V0
ON
RZ
RN
100
50
100
50
0
0
-50
-100
-50
-100
2.5
5
2.5
5
5
5
0
0
0
0
Time (µs)
Time (µs)
(a)
(a)
300
250
200
150
300
250
200
150
100
50
100
50
0
0
-50
-100
-50
-100
2.5
Time (µs)
(b)
2.5
5
0
Time (µs)
(b)
300
250
200
150
300
250
200
150
100
50
100
50
0
0
-50
-100
-50
-100
2.5
2.5
5
0
Time (µs)
Time (µs)
PI-2885-061002
PI-2884-061002
(c)
(c)
Figure 7. Normal DPA-Switch Drain Waveforms Showing Correct
Transformer Reset. a) VIN = 72 V, b) VIN = 48 V,
c) VIN = 36 V.
Figure 8. Illustration of Three Situations with Improper
Transformer Reset. a) VIN = 72 V, b) VIN = 36 V,
c) VIN = 36 V.
C
7/04
9