TOP242-250
BENCH TEST PRECAUTIONS FOR EVALUATION OF ELECTRICAL CHARACTERISTICS
The following precautions should be followed when testing
TOPSwitch-GX by itself outside of a power supply. The
schematicshowninFigure53issuggestedforlaboratorytesting
of TOPSwitch-GX.
while in this auto-restart mode, there is only a 12.5% chance
that the CONTROL pin oscillation will be in the correct state
(drainactivestate)sothatthecontinuousdrainvoltagewaveform
may be observed. It is recommended that the VC power supply
be turned on first 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.
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 V and 5.8 V and
the drain is turned on every eigth cycle of the CONTROL pin
oscillation. If the CONTROL pin power supply is turned on
Typical Performance Characteristics
PI-2653-031904
1.1
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
Scaling Factors:
TOP242 P/G/Y/R/F: .45
200
TOP243 P/G:
TOP243 Y/R/F:
TOP244 P/G:
.75
.90
1
180
160
140
TOP244 Y/R/F:
TOP245 Y/R/F:
TOP246 Y/R/F:
TOP247 Y/R/F:
TOP248 Y/R/F
TOP249 Y/R/F:
TOP250 Y/R/F:
1.35
1.80
2.70
3.60
4.50
5.40
6.32
120
100
80
60
0.2
-250
40
0
-200
-150
-100
-50
IX or IM (µA)
Figure 54a. Current Limit vs. X or M Pin Current (see Figures 55a and 56a for TOP245P and TOP246P).
PI-2652-042303
1.1
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
Scaling Factors:
TOP242 P/G/Y/R/F: .45
200
180
TOP243 P/G:
.75
.90
1
TOP243 Y/R/F:
TOP244 P/G:
160
140
TOP244 Y/R/F:
TOP245 Y/R/F:
TOP246 Y/R/F:
TOP247 Y/R/F:
TOP248 Y/R/F
TOP249 Y/R/F:
TOP250 Y/R/F:
1.35
1.80
2.70
3.60
4.50
5.40
6.32
Maximum
Minimum
120
100
80
Typical
Maximum and minimum levels
are based on characterization.
60
40
0.2
0
5K
10K
15K
20K
25K
30K
35K
40K
45K
External Current Limit Resistor RIL (Ω)
Figure 54b. Current Limit vs. External Current Limit Resistance (see Figures 55b and 56b for TOP245P and
TOP246P).
M
40 12/04
POWERINT [ Power Integrations ]
