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

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 vs. TEMPERATURE

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

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

2

1.2

1.6

0

020

4060

80

100

Drain Voltage (V)

0.4

0.8

VC = 5 V