Datasheet
TOP242-250
41
I
4/03
The following precautions should be followed when testing
TOPSwitch-GX by itself outside of a power supply. The sche-
matic 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
BENCH TEST PRECAUTIONS FOR EVALUATION OF ELECTRICAL CHARACTERISTICS
Typical Performance Characteristics
while in this auto-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 wave-
form may be observed. It is recommended that the V
C
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.
Figure 54. Current Limit vs. MULTI-FUNCTION Pin Current.
Figure 55. Current Limit vs. External Current Limit Resistance.
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
1.1
60
40
80
100
120
140
160
180
200
-250 -200 -150 -100 -50
I
M
(µA)
Current Limit (A)
di/dt (mA/µs)
PI-2653-042203
0
Scaling Factors:
TOP242 P/G/Y/R/F: .45
TOP243 P/G: .75
TOP243 Y/R/F: .90
TOP244 P/G: 1
TOP244 Y/R/F: 1.35
TOP245 Y/R/F: 1.80
TOP246 Y/R/F: 2.70
TOP247 Y/R/F: 3.60
TOP248 Y/R/F 4.50
TOP249 Y/R/F: 5.40
TOP250 Y/R/F: 6.32
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
1.1
60
40
80
100
120
140
160
180
200
05K10K 15K 20K 25K 30K 35K 40K
External Current Limit Resistor R
IL
(Ω)
Current Limit (A)
di/dt (mA/µs)
PI-2652-042303
45K
Maximum and minimum levels
are based on characterization.
Minimum
Typical
Maximum
Scaling Factors:
TOP242 P/G/Y/R/F: .45
TOP243 P/G: .75
TOP243 Y/R/F: .90
TOP244 P/G: 1
TOP244 Y/R/F: 1.35
TOP245 Y/R/F: 1.80
TOP246 Y/R/F: 2.70
TOP247 Y/R/F: 3.60
TOP248 Y/R/F 4.50
TOP249 Y/R/F: 5.40
TOP250 Y/R/F: 6.32