SBOS622A July 2018 – October 2018 OPA855
Figure 55 shows the OPA855 configured as a transimpedance amplifier (U1) in a wide-bandwidth, optical front-end system. A second amplifier, the OPA859, configured as a unity-gain buffer (U2) sets a dc offset voltage to the THS4520. The THS4520 is used to convert the single-ended transimpedance output of the OPA855 into a differential output signal. The THS4520 drives the input of the ADS54J64, 14-bit, 1-GSPS analog-to-digital converter (ADC) that digitizes the analog signal.