Other Parts Discussed in Thread: OPA564,
Hi,
I want to design an "AC excitation" module to excite a coil between 100 kHz and 200 kHz (R=2 Ohm at DC, Z=50 Ohm at 150 kHz). I have a DDS (AD9833) which can generate sine wave with peak voltage of 0.65 V at 150 kHz. I want to amplify the signal with a power amplifier which can amplify the voltage to around 12 V (Gain=18) and provide sufficient current. I found two amplifiers: one is OPA564 and the other is THS3122.
1. THS3122 has 450 mA output current, 26 Vpp Output voltage (RL=50 Ω), and 128 MHz -3dB BW so it seems that the gain is flat above 150 kHz. Is it correct?
2. My second question is that whether OPA564 is also a choice? My main concern is its GBW, which is 17 MHz. Suppose the gain is 20, the BW is then 17M/20=850 kHz, does that mean it is still sufficient for this application (100 kHz-200kHz)?