DPA422 Datasheet, PDF (27/36 Pages) Power Integrations, Inc. – Highly Integrated DC-DC Converter ICs for Power over Ethernet & Telecom Applications

DPA422-426
BENCH TEST PRECAUTIONS FOR EVALUATION OF ELECTRICAL CHARACTERISTICS
The following precautions should be followed when testing
DPA-Switch by itself outside of a power supply. The schematic
shown in Figure 33 is suggested for laboratory testing of
DPA-Switch.
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 V 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
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
waveform 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 DPA-Switch, which
then will come up in the correct state.
1.1
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
-230
-180
-130
-80
I_X (μA)
Figure 34. Current Limit vs. EXTERNAL CURRENT LIMIT Pin Current.
-30
0
1.1
1.0
0.9
Maximum
0.8
0.7
Minimum
0.6
0.5
Typical
0.4
0.3
0.2
0.1
0
5
10
15
20
25
30
35
External Current Limit Resistor R_IL (kΩ)
Figure 35. Current Limit vs. External Current Limit Resistance.
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27
Rev. S 12/07