I am going to design using ADA4870.The voltage range is shown in 10 to 40V.Is plus, minus 20V the maximum?
One question more,The figure below shows "Up to 60 Vpp 1A with external BJT."Is the range plus, minus 30 volts?Please share the BJT circuit.
OK, The ADA4870 does not have a spec.If you find the document "Up to 60 Vpp 1A with external BJT," please share it.
Long time no see~
The circuit was designed using the above document (dynamic class A).However, heat was generated and the FET was broken.Can you tell me what the problem is?
There is one more question.How do I design Dynamic Class AB?Please share the schematic diagram of Dynamic Class AB.
Apology if I didn't get back fast.
We cannot find the circuit that suggests using BJT to achieve that waveform snapshot but we have a characterization board w/c uses FET for bootstrapping.
Here is the schematic:
Please note, adequate thermal management may be required for higher power dissipation.
Also,optimal performance (voltage swing, slew rate, settling time and power supply requirements) depends on proper choice of bootstrapping MOSFET devices and associated discrete components.
Long time no see.
My client started the project again.The circuit was constructed as shown in the attached document.However, the output value could not be exported to +-25V .Can you tell me what the problem is?
I am going to use the circuit below because it doesn't work.Can you tell me the value of the resistance capacitor?It's best to deliver the correct circuit.
Can you double check the placement of the MOSFETs?
The N-Channel (IRF610) should be the one connected to the VCC of the ADA4870 and the P-Channel (IRF9610) is on the Vee. Also, what is the value of your R4 and R5? I can see two labels, 300 and 8.2k.I assume this is 8.2k and that is the parallel combination of two 16k from the original schematic.
Also, below is a simulation of the circuit though I have use different model for the P-channel MOSFET( chosen as it is available in library). You can see that the output swing ~47Vpp for an input of 12Vpp at the gain of 5.The output is already beyond the allowable supply voltage of the ADA4870 which is only 40V.
Again, please do note that adequate thermal management is required for power dissipation.
Here is an additional Application Note that will help you with this concept.https://www.analog.com/media/en/technical-documentation/application-notes/AN-1593.pdf
Thanks and regards.