PGA309: Speeding up Response Time

Hi Jejomar,

The PGA309 datasheet shows the large-signal step response on Figure 15 - Gain=8, and Figure 16 - Gain = 1152 V/V of datasheet, where the settling time is around ~10μs.  Keep in mind, this is the response of the amplifier stand-alone. 

However, please keep in mind, the response of the complete PGA309 circuit will depend on the circuit feedback configuration, RC filters and load components involved.

Attached is an application note that discusses PGA309 noise filtering, feedback configurations, for the PGA309 that you may find useful.  There will be a trade-off between the noise and bandwidth of the circuit.

PGA309 Noise Filtering (Rev. A) - Texas Instruments

Can you please share the schematic showing the RC filters and load components used? 

What gain range  used in this application?

What is the response time target requirement?

Thank you and Regards,

Luis

Hi Luis,

Thank you for looking into this. We used no other components on the output of PGA309. Looks like PGA309 is the slowest component of the circuit. The input into PGA309 is 100mV and output 0.6Vds at zero input and 4.1Vdc at 100mV input, therefore gain is 35. I'll be sending the schematic to you via private messaging for proprietary reasons. We measure output between Pins 3 and 4 of J3. Pin 3 marked incorrectly on schematic. Should be “+ Output”.

Looking forward to your comments!


Kind Regards,

Jejomar

HI Jejomar,

I have received the schematic, and will be providing a response via private message per your request.

I should be able to provide a detailed response via private message by tomorrow.

Thank you and Best Regards.

Luis