Our office will be closed from May 12th, 2021 to May 16th, 2021. Orders placed during this time will be processed starting on May 17th, 2021.

PD10TIA User Guide

Last updated: 2020-02-19 PDF version


PD10TIA-80-DC photodetector user interface
  1. Supply +VCC pin with a voltage between 5.5 V and 9 V. Supply -VCC pin with a voltage between -5.5 V and -9 V. The board is regulated to ±5 V internally. Using more than ±6 V supplies increases power consumption without any significant improvement in supply noise rejection.

  2. Feed the SMA input with a maximum of 50 µA. The linear output voltage range of the transimpedance amplifier is between -3.7 V and +3.7 V.

  3. The output is available on the SMA connector (50 Ω impedance).

Interfacing photodiodes to the PD10TIA

The PD10TIA is designed to be used with external photodiodes. Here is the recommended way to interface the photodiodes with the PD10TIA using a coaxial cable.

On the diagrams Cd and Ccoax represent the parasitic capacitance of the photodiode and the coaxial cable, respectively.

Single-ended detector

PD10TIA-80-DC Single-ended detector mounting

Balanced detector

PD10TIA-80-DC Balanced detector mounting

Coaxial cable length and input capacitance

The input capacitance is Cin = Cd + Ccoax for a single-ended detector and Cin = 2 Cd + Ccoax for a balanced one. The PD10TIA-80-DC is stable with input capacitances up to 2 nF.

For a typical 50 Ω coaxial cable, the capacitance per unit of length is 1 pF / cm. Note that no specific characteristic impedance is required for the input coaxial cable.

The input capacitance mostly influences the noise performance of the amplifier. For example, we built a balanced detector using a pair of photodiodes with 0.9 A / W sensitivity and Cd = 5 pF. We measured the noise equivalent power without and with a 2 meter-long coaxial cable (Ccoax = 1 pF / cm x 200 cm = 200 pF):

PD10TIA-80-DC Input noise versus coaxial cable length

Can't find your answer? Contact us
[email protected]