TOP242 Power Integrations Inc., TOP242 Datasheet - Page 41

• Manufacturer Part Number: TOP242
• Description: Family Extended Power/ Design Flexible/Integrated Off-line Switcher
• Manufacturer: Power Integrations Inc.

The following precautions should be followed when testing
TOPSwitch-GX by itself outside of a power supply. The
schematic shown in Figure 53 is suggested for laboratory
testing of TOPSwitch-GX.
When the DRAIN pin supply is turned on, the part will be in the
auto-restart mode. The CONTROL pin voltage will be oscillating
at a low frequency between 4.8 and 5.8 V and the drain is turned
on every eighth cycle of the CONTROL pin oscillation. If the
CONTROL pin power supply is turned on while in this auto-
Typical Performance Characteristics
BENCH TEST PRECAUTIONS FOR EVALUATION OF ELECTRICAL CHARACTERISTICS
Figure 54. Current Limit vs. MULTI-FUNCTION Pin Current.
Figure 55. Current Limit vs. External Current Limit Resistance.
1.1
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
1.1
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
-250
0
Maximum and minimum levels
are based on characterization.
Minimum
5K
-200
Typical
10K
External Current Limit Resistor R
15K
Maximum
-150
20K
I
M
(µA)
restart mode, there is only a 12.5% chance that the CONTROL
pin oscillation will be in the correct state (drain active state) so
that the continuous drain voltage waveform may be observed.
It is recommended that the V
and the DRAIN pin power supply second if continuous drain
voltage waveforms are to be observed. The 12.5% chance of
being in the correct state is due to the divide-by-8 counter.
Temporarily shorting the CONTROL pin to the SOURCE pin
will reset TOPSwitch-GX, which then will come up in the
correct state.
25K
-100
30K
IL
(Ω)
Scaling Factors:
TOP242:
TOP243 P/G:
TOP243 Y/R:
TOP244 P/G:
TOP244 Y/R: 1.35
TOP245 Y/R: 1.80
TOP246 Y/R: 2.70
TOP247 Y/R: 3.60
TOP248 Y/R: 4.50
TOP249 Y/R: 5.40
35K
-50
Scaling Factors:
TOP242:
TOP243 P/G:
TOP243 Y/R:
TOP244 P/G:
TOP244 Y/R: 1.35
TOP245 Y/R: 1.80
TOP246 Y/R: 2.70
TOP247 Y/R: 3.60
TOP248 Y/R: 4.50
TOP249 Y/R: 5.40
August 8, 2000
.45
.75
.90
C
1
power supply be turned on first
40K
PI-2653-033001
PI-2652-033001
.45
.90
.75
1
TOP242-249
45K
0
200
180
160
140
120
100
80
60
40
200
180
160
140
120
100
80
60
40
7/01
E
41