ILC Hybrid MOSFET/Driver Module Update T. Tang, C. Burkhart September 29, 2011

New Improvements Modular design facilitates rapid prototyping –Only flip chip MOSFETs and essential supporting circuitry on the HSM –Simplified flip chip circuit to reduce fabrication cost –Possible to reuse HSM and external driver Improved circuit for high frequency operation and short pulse generation –More decoupling capacitors for high frequency (up to 6MHz) burst generation –Improved front end driver for shorter pulse width (limited success)

Schematic and Photos Schemati c of test setup Photo of test setup Detailed photos of HSM

Test Results Waveforms from 6MHz 20-pulse burst Above, the detailed view of the first pulse of the train. Below, a potion of the burst train. Charge voltage: 1000V, load: 50 ohm, CH2: load voltage, CH3: M1 gate voltage Gate voltage and power MOSFET switching speed for each pulse in the train. Left axis: gate voltage (blue), Right axis: switching speed (red).

Summary and Future Work The new switch module is a more modular design. The new HSM demonstrated <1.5ns switching time at 6MHz burst operation. –Still small (<0.2ns) fluctuation in switching speed. –A correlation between the switching speed and the peak gate voltage was observed –Further investigation is in progress. Initial attempt to reduce minimal pulse width is not very successful. –No improvement compared with the old HSM (~10ns) –Further tuning of the HSM driver is needed Optimization of driver voltage and output resistance Using parallel driver