A
4/99
TOP412/414
13
The following precautions should be followed when testing
TOPSwitch by itself outside of a power supply. The schematic
shown in Figure 11 is suggested for laboratory testing of
TOPSwitch.
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 is turned
on every eighth cycle of the CONTROL pin oscillation. If the
BENCH TEST PRECAUTIONS FOR EVALUATION OF ELECTRICAL CHARACTERISTICS
Typical Performance Characteristics
CONTROL pin power supply is turned on 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 waveform may be
observed. It is recommended that the V
C
power supply be
turned on first and the DRAIN 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 8:1 counter.
1.1
1.0
0.9
-50 -25 0 25 50 75 100 125 150
Junction Temperature (°C)
Breakdown Voltage (V)
(Normalized to 25 °C)
BREAKDOWN vs. TEMPERATURE
PI-176B-051391
1.2
1.0
0.8
0.6
0.4
0.2
0
-50 -25 0 25 50 75 100 125 150
Junction Temperature (°C)
FREQUENCY vs. TEMPERATURE
PI-1123A-060794
Output Frequency
(Normalized to 25 °C)
1.2
1.0
0.8
0.6
0.4
0.2
0
-50 -25 0 25 50 75 100 125 150
Junction Temperature (°C)
CURRENT LIMIT vs. TEMPERATURE
PI-1125-041494
Current Limit
(Normalized to 25 °C)
2
1.2
1.6
0
020406080100
Drain Voltage (V)
CONTROL Pin
Charging Current (mA)
I
C
vs. DRAIN VOLTAGE
PI-1145-103194
0.4
0.8
V
C
= 5 V
