This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

THS3122: GBW Question of OPA564 vs THS3122, which is appropriate to excite/push a coil at ~150 kHz?

Part Number: THS3122
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)?