PD10TIA User GuideLast updated: 2020-02-19 PDF version
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.
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.
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.
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):