Photodiode transimpedance amplifier, on a one inch diameter (25 mm) circular 2-sided PCB - for mounting in standard 1" lens holders.

The board features low-noise LDOs LT3042 and LT3093 to produce +V and -V DC-rails for the op-amp. The photodiode footprint is TO-18, to fit e.g. Hamamatsu Si photodiodes S5973, S5972, S5973, or Thorlabs Si detectors FDS015, FDS025, FD11A, or Thorlabs InGaAs detectors such as FGA01, FGA01FC, FGA015, FDGA05, FD05D, FD10D.

The output is DC-coupled to a MMCX connector, to fit the small board.

This version of the detector is for a SOT23 op-amp such as OPA657(FET 1.6GHz), OPA847(bipolar 3.9GHz), and similar.

Example designs

• OPA657 op-amp, S5973 photodiode, 10 kOhm RF, around 59 MHz -3 dB bandwidth. With measured signal and noise spectra

This version is for modern op-amps in WSON8 footprint such as OPA855(bipolar 8GHz), OPA858(FET 5.5GHz), OPA859(FET 1.9GHz)