How to check physical working of PHEMT transistor(ATF54143) usinf Digital Multimeter.

[pusparaga]

How to check physical working of PHEMT transistor(ATF54143) using Digital Multimeter.

Sir,
I have used the Pseudomorphic HEMT(PHEMT) AVAGO TECHNOLOGIS ATF54143 transistor to my work. I want to conform the working of ATF54143 PHEMT transistor. Using the DIGITAL MULTIMETER , how to check whether working or not the ATF54143 PHEMT transistor. It has four terminals one gate and drain, two sources. For forward bias which terminals connect the positive and which terminals connect the black for checking the working condition of ATF54143 PHEMT transistor. Similarly for reverse biasing, which terminals we have to connect for positive and ground using DIGITAL MULTIMETER.
I have one more doubt PHEMT ATF 54143 AVAGO Technologies is it a P CHANNEL FET or N CHANNEL FET. Please guide me how to check the PHEMT transistor working functionality using DIGITAL MULTI METER.

 

[afz23]

Checking HEMT or any GaAsFET with multimeter is never recommended,as it flows current into the terminals to measure parameters,the current can damage the gate of these devices.

If you have a test jig,use that,by giving gate and drain voltages thru bias tees and measure actual currents.

 

[pusparaga]

Dear Sir,
I have used my circuit to PHEMT (Avago ATF54143) transistor and fabricated. Now I am getting the totally erroneous results of fabricated piece as compared to simulated results. Now I am getting the doubt on PHEMT transistor whether it is working or not , I don't know. I want to check the transistor whether working or not. I think , transistor is not working. How to check the working of PHEMT transistor using DIGITAL MULTIMETER or any other device. If we use to check the any other device , tell me which device we can use to check PHYSICAL WORKING of PHEMT transistor other than DIGITAL MULTIMETER. If we use the DIGITAL MULTIMETER , how we have to check working of PHEMT transistor.

 

[pusparaga]

Sir,
Help someone else to resolve this problem

 

[mtwieg]

As the previous reply stated, you shouldn't test with just a multimeter, at least not with a resistance measurement, since the applied bias may damage the device. Same reason you shouldn't test the device with a hammer...

Applying proper bias voltages and measuring the gate and drain currents with multimeters is a more effective and safe method.

 

[biff44]

like the others said, it can not be done.

The main problem I would see is that the transistor would oscillate even if you could get a reading with a multimeter--rendering that reading meaningless.

If you need to test it, I would recommend making a microwave test fixture. The gate and drain would need DC blocking series capacitors and 50 ohm terminations to ground. There would be a terminal on the test fixture for gate bias, and another one for drain bias. The gate bias structure would be properly designed using S parameter technique to not cause an oscillation, and to only let very low frequencies out that bias terminal. Similarly, the drain bias structure would do the same, but probably have perhaps a 200 ohm series resistor in it (to limit current). The device will need excellent grounds from the source to ground with vias close to the package.

After building such a test fixture, you would hook up the drain to a standard dc power supply with a current meter. You would hook up a similar power supply to the gate bias network. Varying the gate voltage should result in the drain current going from zero to some maximu level. That confirms it is a working device.

Do NOT exceed the voltage and current maximums for the device! Otherwise it will be a very short test