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Measurement Procedures
1) Slew Rate dV/dT tests
Initial steps:
Do all the necessary connection between the evaluation board,
components and equipment.
Connect DC power ① to VPN and VS of the board with
the screw terminal block.
Connect deadtime circuit to the IN_H, IN_L, VDD, EN and
GND terminal of the board. Please note that the connection of
dead time circuit to the IN_H and IN_L depending on low side
test or high side test (please refer to page 11).
Connect the inductor from VPN to LX for boost mode (low side test)
or connect inductor from LX to VS for buck mode (high side test).
The VDD voltage must be 3.3V-5V, Isolator VDDI voltage range.
Fix the dead time to 100ns.
Connect the dead time generator to a pulse generator.
Connect DC power ② to VDD/GND terminal of the board to3.3/5V.
Connect DC power ③ to AUXH+/AUXH-, AUXL+/AUXL- terminal of
the board.
Probe the point where you want to monitor and observe the
waveform using oscilloscope.
Be careful not to short with other parts. It is recommended to use a coil
wire fixture mounted near SMA2 on the evaluation board for V
refer to Figure 11.
Use an SMA to Tektronics probe adaptor as shown in Figure 12.
Start-up:
Set up the Dead time generator circuit with the amplitude 0-5V and having the double pulse profile as
shown below:
Figure 13: Double Pulse
Again, ensure that the pulse generated occurs only in the burst mode. If the pulse is generated
continuously, the transistor will be damaged by high current flows.
Set DC power ②to 5V. LED will glow to indicate EN (Si8275GB Enable pin) is high
Adjust DC power ③ to 12V gradually.
Check V
waveform when a double pulse is inputted from pulse generator. Ensure to carry out this step
GS
with DC power ① is set to 0V.
Then, the voltage of DC power ① is gradually increased from 0V to predetermined voltage (400V).
Monitor the VDS voltage with oscilloscope and confirm that the V
Input a double pulse with the pulse generator again and check the V
Observation of waveform will be easier if the trigger is applied at the rising / falling edge of V
shown on Figure 13 above.
If different inductor value is used other than the suggested, please set the pulse width until the desired IL
value is achieved.
PGA26E19BA-SWEVB008 Ver. 1.1
monitoring
DS
Table 5: Double Pulse Setting with L=320uH
IL
2.5A
5A
7.5A
10A
voltage rises to the set value.
DS
15
Figure 11: Usage of coil wire
Figure 12: SMA to Probe
#1
2.3µs
4.6µs
6.9µs
9.2µs
, V
and IL waveform.
GS
DS
or V
as
GS
DS
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