I am using ADL5511 to be an Envelope Detector, and the modulated signal is 0.4 Hz, and the carrier signal is 1 MHz. The signal is from the output of OPA657, which is regarded as an charge amplifier. Based on datasheet of ADL 5511, "As a general guideline, this corner frequency should be set to at least tenth of the minimum expected carrier frequency", which is for Cflt1. In my application, I set the corner frequency to 100Khz, which means Cflt1=154pF. And also based on datasheet, I chose Cflt2=2 microF, Cflt3=3.3 microF, and Cflt4=398 microF. However, I cannot get right results on oscilloscope. I am wondering can anyone give me some solution? Thank you.