TOP209/210
NOTES: (continued)
i. The 470 Ω 5 W load resistor at the DRAIN pin should be shorted. S1 & S2 should stay closed.
ii. The 40 V output supply should be replaced with a curve tracer capable of forcing 700 V.
iii. The curve tracer should initially be set at 0 V. The 0-50 V variable supply should be adjusted through a voltage
sequence of 0 V, 6.5 V, 4.2 V, and 6.5 V.
iv. The breakdown and the leakage measurements can now be taken with the curve tracer. The maximum
voltage from the curve tracer must be limited to 700 V under all conditions.
C. It is possible to start up and operate TOPSwitch at DRAIN voltages well below 36 V. However, the CONTROL pin
charging current is reduced, which affects start-up time and auto-restart frequency and duty cycle. Refer to the
characteristic graph on CONTROL pin charge current (IC) vs. DRAIN voltage for low voltage operation characteristics.
TYPICAL CONTROL PIN I-V CHARACTERISTIC
120
100
t
2
80
60
40
20
0
t
1
HV
90%
90%
t
t
DRAIN
VOLTAGE
1
2
Dynamic
Impedance
1
D =
=
Slope
10%
0 V
0
2
4
6
8
10
PI-2048-050798
CONTROL Pin Voltage (V)
Figure 10. TOPSwitch Duty Cycle Measurement.
Figure 11. TOPSwitch CONTROL Pin I-V Characteristic.
470 Ω
5 W
2
S2
470 Ω
D
S
C
S
S1
40 V
0.1 µF
47 µF
0-50 V
NOTE: This test circuit is not applicable for current limit or output characteristic measurements.
PI-1733-122095
Figure 12. TOPSwitch General Test Circuit.
A
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POWERINT [ Power Integrations ]
