GSWP050W-EVBPA
GaN E-HEMT Wireless Power Transfer Evaluation Board
User’s Guide
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GSWP050W-EVBPA Rev 190304
© 2019 GaN Systems Inc.
www.gansystems.com 11
Please refer to the Evaluation Board/Kit Important Notice on page 22
Overvoltage protection (OVP): The design includes overvoltage protection circuitry for both the
high side and the low side. The high side voltage sensor is comprised of C276, C277, and two
Schottky diodes; D52 and D44. C276/C277 form a voltage divider, the ratio of which can be
changed. Two diodes rectify the RF signal to DC thru C278/C22 and R111 and the resulting voltage
represents the high side output. The low side circuit is similar. It’s comprised of C270, C280, and
two diode D50, D53. These two voltage detection signals go to a two-channel comparator U68 and
are combined with OR gate U70 into one overvoltage trigger, OVP_TRIG.
The OVP and OCP go into a hard combine circuit D45, which a dual diode in one. To generate an
overcurrent / overvoltage protection trigger signal.
Figure 12 •
Connectivity locations
Thermal Management
Thermal management of the GaN E-HEMTs in this RF power system is a critical aspect of the
design. Maintaining low device temperatures through proper thermal management enhances the
system reliability and extends the range of operating temperature.
The GS61004B are bottom-side cooled devices that use GaN
PX
® packaging, designed for optimal
thermal performance. For effective thermal management, a hole is cut out of the PCB to permit
access to the copper coins. The two GS61004Bs’ bottom side thermal pads are soldered directly onto
the copper coin on the bottom side of the PCB and the Gate, Drain and Source signals are routed on
the top side of the PCB. This set up provides an ultra-low thermal impedance from the die to the