TNY263-268
V
EN
PI-2381-1030801
200
100
0
10
V
DC-INPUT
CLOCK
D
MAX
5
0
V
BYPASS
I DRAIN
400
200
0
0
1
2
V
DRAIN
V DRAIN
Time (ms)
Figure 11. TinySwitch-II Power-up without Optional External UV
Resistor Connected to EN/UV Pin.
PI-2661-072400
PI-2348-030801
Figure 9. TinySwitch-II Operation at Very Light Load.
200
100
V
DC-INPUT
During power-down, when an external resistor is used, the
power MOSFET will switch for 50 ms after the output loses
regulation. The power MOSFET will then remain off without
any glitches since the under-voltage function prohibits restart
when the line voltage is low.
Figure 12 illustrates a typical power-down timing waveform of
TinySwitch-II.
Figure 13 illustrates a very slow power-down
timing waveform of
TinySwitch-II
as in standby applications.
The external resistor (2 MΩ) is connected to the EN/UV pin
in this case to prevent unwanted restarts.
0
400
300
200
100
0
0
.5
1
V
DRAIN
Time (s)
Figure 12. Normal Power-down Timing (without UV).
PI-2383-030801
100
0
10
5
0
400
200
0
0
V
DC-INPUT
200
100
0
V
DC-INPUT
V
BYPASS
400
300
200
V
DRAIN
V
DRAIN
100
0
1
2
0
2.5
5
Time (ms)
Time (s)
Figure 10. TinySwitch-II Power-up with Optional External UV
Resistor (2 MΩ) Connected to EN/UV Pin.
Figure 13. Slow Power-down Timing with Optional External
(2 MΩ) UV Resistor Connected to EN/UV Pin.
6
G
4/05
PI-2395-030801
200
POWERINT [ POWER INTEGRATIONS, INC. ]
