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Dear,
I need technical insight for the following issue.
I have the requirement of Gate pulsing of an RF GaN FET and pulsing requirements are as below,
The device is from MACOM and it is an RF GaN Transistor which operates at 28VDC.
The device needs to be pulsed to get RF output and the PRF varies from 200KHz to 600KHz and duty is 35%. The Rise and Fall time at RF Output is <50 nanoseconds and the harmonics level need to be <-45dB with respect to carrier.
The GaN Drain is always applied with +28V DC from Power supply rail.
The Device is depletion mode GaN FET and the gate bias swings between -4.5 V( Full OFF) and 0V (Full ON). The input modulating circuit receives TTL level signal and the GaN device need to be pulsed accordingly. How to Switch the gate voltage meeting the timing and rise/Fall time requirement is the problem and need a reliable fail safe (Gate must be pulled to -4.5V, OFF state) if no modulation input is present). Looking for a practical, temperature-controlled circuit for Gate pulsing of the Depletion mode GaN FET.
There are Low side Gate drivers available in the marker, but this GaN gate drivers are for Enhancement mode MOSFET Switches and switches the Gate voltages 0 to +ve voltage rails. My requirement is to switch from -4.5V to 0V rail. How I can design a good Gate pulsing circuit?
I have +28V DC available in the PCB and generated +5V (Using LT3012HFE) and -5V (Using LTC1261LIS8-4.5, Switched inverter) for DC Voltage generation.
Can you please suggest a Gate driver for Depletion mode D-mode RF Power Amplifier for 500KHz PRF switching (-5V to 0V gate voltage swing)
The input Digital signal for modulation is in TTL level (0V/5V) from a micro controller and RF GaN gate need to be pulsed between -4.5V to 0V for Gate switching and rise and fall time must be <30ns.
There are Gate drivers like UCC27532/ UCC27517A etc are available, but these are useful for E-Mode GaN Gate driving since it operates at 0V/+5V levels. Anybody can help /explain whether this two ICs can be used for D-Mode GaN Gate driving with (-5V/0V) voltage levels?
From literature, it is suggested to use Two complementary Transistor pairs (NPN/PNP) (eg: BFR92A/ BFR92) or PMBT5551/MMBTA56) with baker clamp diode for switching between -5V and 0V which can be applied to D-Mode RF GaN Transistor. But I am not sure about the performance about the rise and fall time.
Can someone help me?
Thanks in advance.
I need technical insight for the following issue.
I have the requirement of Gate pulsing of an RF GaN FET and pulsing requirements are as below,
The device is from MACOM and it is an RF GaN Transistor which operates at 28VDC.
The device needs to be pulsed to get RF output and the PRF varies from 200KHz to 600KHz and duty is 35%. The Rise and Fall time at RF Output is <50 nanoseconds and the harmonics level need to be <-45dB with respect to carrier.
The GaN Drain is always applied with +28V DC from Power supply rail.
The Device is depletion mode GaN FET and the gate bias swings between -4.5 V( Full OFF) and 0V (Full ON). The input modulating circuit receives TTL level signal and the GaN device need to be pulsed accordingly. How to Switch the gate voltage meeting the timing and rise/Fall time requirement is the problem and need a reliable fail safe (Gate must be pulled to -4.5V, OFF state) if no modulation input is present). Looking for a practical, temperature-controlled circuit for Gate pulsing of the Depletion mode GaN FET.
There are Low side Gate drivers available in the marker, but this GaN gate drivers are for Enhancement mode MOSFET Switches and switches the Gate voltages 0 to +ve voltage rails. My requirement is to switch from -4.5V to 0V rail. How I can design a good Gate pulsing circuit?
I have +28V DC available in the PCB and generated +5V (Using LT3012HFE) and -5V (Using LTC1261LIS8-4.5, Switched inverter) for DC Voltage generation.
Can you please suggest a Gate driver for Depletion mode D-mode RF Power Amplifier for 500KHz PRF switching (-5V to 0V gate voltage swing)
The input Digital signal for modulation is in TTL level (0V/5V) from a micro controller and RF GaN gate need to be pulsed between -4.5V to 0V for Gate switching and rise and fall time must be <30ns.
There are Gate drivers like UCC27532/ UCC27517A etc are available, but these are useful for E-Mode GaN Gate driving since it operates at 0V/+5V levels. Anybody can help /explain whether this two ICs can be used for D-Mode GaN Gate driving with (-5V/0V) voltage levels?
From literature, it is suggested to use Two complementary Transistor pairs (NPN/PNP) (eg: BFR92A/ BFR92) or PMBT5551/MMBTA56) with baker clamp diode for switching between -5V and 0V which can be applied to D-Mode RF GaN Transistor. But I am not sure about the performance about the rise and fall time.
Can someone help me?
Thanks in advance.
