TOP221-227
BENCH TEST PRECAUTIONS FOR EVALUATION OF ELECTRICAL CHARACTERISTICS
The following precautions should be followed when testing
TOPSwitch by itself outside of a power supply. The schematic
shown in Figure 14 is suggested for laboratory testing of
TOPSwitch.
Auto-restart mode, there is onlya 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 VC power supply be
turnedonfirstandtheDRAINpowersupplysecondifcontinuous
drainvoltagewaveformsaretobeobserved. The12.5%chance
ofbeinginthecorrectstateisduetothe8:1counter. Temporarily
shorting the CONTROL pin to the SOURCE pin will reset
TOPSwitch, which then will come up in the correct state.
When the DRAIN supply is turned on, the part will be in the
Auto-restart mode. The CONTROL pin voltage will be
oscillating at a low frequency from 4.7 to 5.7 V and the DRAIN
isturnedoneveryeighthcycleoftheCONTROLpinoscillation.
If the CONTROL pin power supply is turned on while in this
Typical Performance Characteristics
BREAKDOWN vs. TEMPERATURE
FREQUENCY vs. TEMPERATURE
1.1
1.2
1.0
0.8
0.6
0.4
0.2
1.0
0.9
0
-50 -25
0
25 50 75 100 125 150
-50 -25
0
25 50 75 100 125 150
Junction Temperature (°C)
Junction Temperature (°C)
CURRENT LIMIT vs. TEMPERATURE
I vs. DRAIN VOLTAGE
C
1.2
2
V
= 5 V
C
1.0
0.8
0.6
0.4
0.2
1.6
1.2
0.8
0.4
0
0
-50 -25
0
25 50 75 100 125 150
0
20
40
60
80
100
Junction Temperature (°C)
DRAIN Voltage (V)
C
16
12/97
POWERINT [ Power Integrations ]
