Gan Systems GS66502B-EVBDB, Руководство пользователя

Страница: 6 / 33


The board provides an optional current shunt position JP1 between the source of Q2 and power
ground return. This allows drain current measurement for switching characterization test such as
Eon/Eoff measurement.

The JP1 footprint is compatible with T&M Research SDN series coaxial current shunt
(recommended P/N: SDN-414-10, 2GHz B/W, 0.1Ω)

If current shunt is not used JP1 must be shorted. JP1 affects the power loop inductance and its
inductance should be kept as low as possible. Use a copper foil or jumper with low inductance.
1. When measuring VSW with current shunt, ensure all channel probe grounds and current shunt
BNC output case are all referenced to the source end of Q2 before the current shunt. The
recommended setup of probes is shown as below.
2. The output of coaxial current shunt can be connected to oscilloscope via 50Ω termination
impedance to reduce the ringing.
3. The measured current is inverted and can be scaled by using: Id=Vid/Rsense.
Current
Shunt
Q2 Source
VDC-