THS7530-Q1: Gain control signal and external resistor network for adjustable gain

Yoshiki Ochi

Part Number: THS7530-Q1
Other Parts Discussed in Thread: THS7530,

Hi team,

Could you tell me what "gain control bandwidth" mean?
I guess "gain control bandwidth" is just for an input signal for VG- and VG+ which is separate from "small signal bandwidth", is it correct?

In addition, can we make its gain range to 5dB to 15dB from 11.6 dB to 46.5 dB (datasheet gain setting spec) by configuring external resistor network?

Regards,
Ochi

over 4 years ago

0 kai klaas69 over 4 years ago

Guru 140200 points

Hi Yoshiki,

assume the gain control bandwidth is 1kHz and you give a sine of 100Hz to the gain control input. Then the amplitude of output signal will change hundred times per second with full change of amplitude, exactly like AM modulation. But if you give a sine of 100kHz to the gain control input, the amplitide of output signal will not show any change of amplitude because the modulation signal is way beyond the gain control bandwidth then.

Translated to the THS7530 the gain control signal can have a frequency of up to 15MHz.

Kai

0 Hasan Babiker31 over 4 years ago

TI__Genius 15565 points

Hello Ochi-san,

Yes the gain control bandwidth is just as you mentioned and Kai has explained. The gain range is internal to the amplifier and isn't set by external resistors.

Best,

Hasan Babiker

0 Yoshiki Ochi over 4 years ago in reply to Hasan Babiker31

TI__Genius 9565 points

Hi Kai-san and Hasan-san,

Thank you for making clear understanding THS7530-Q1 gain control feature.

Regards,
Ochi

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THS7530-Q1: Gain control signal and external resistor network for adjustable gain