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FAQ about OE converter

Design

Question

What was the main reason for choosing GPPO connectors?

Answer

Although GPPO connectors have lower insertion durability than other coaxial types, they were used to reduce the product size by narrowing the pitch between connectors for differential outputs.

Question

Do you use in-house developed TIAs* for your main components?
*TIA = Transimpedance Amplifier

Answer

The TIAs were designed and developed by our company.

Question

How have you tried to reduce the noise level of TIAs?

Answer

The feedback resistance was increased to the extent necessary to meet conversion efficiency specifications, and HBTs* with small transistor sizes were placed in the TIA core section to reduce noise.
*Heterojunction Bipolar Transistor

Question

How is the peaking circuit achieved?

Answer

The peaking circuit was designed to increase the gain in the high frequency range and expand the bandwidth by adding appropriate capacitance to the emitter ground of the TIA core section of the cascade circuit.

Question

What materials are used in the transistor process?

Answer

We have two types of material-based transistor processes: GaAs-based HBTs and InP-based HBTs. Circuits with bandwidths up to about 10 GHz are possible with the GaAs-based system, but when the bandwidth exceeds 30 GHz, the InP-based system is used.

Specifications/Performance

Question

Is a sequence required when turning power on and off?

Answer

Pay attention to the required power on/off sequence because improper operation may cause PD failure. Refer to the Technical Note for details.

Question

What is the output format after OE conversion? 

Answer

This OE converter has differential outputs with higher noise immunity than single outputs. In addition, an AC coupling type is used so as not to affect the drive conditions of devices and modules connected in the following stages.

Question

Is it possible to support an optical wavelength of 850 nm?

Answer

This OE converter uses optical components for the long-wave O to L-bands and does not support 850 nm. Contact us if you require support for the 850-nm band.

Question

What frequency bands are supported?

Answer

The frequency band covers 30 kHz to 45 GHz.

Question

What is the THD (Total Harmonic Distortion) characteristic?

Answer

The THD characteristic is less than 1% at 1 GHz and about 2% at 20 GHz as simulated values.

Applications

Question

What are the target applications for this OE converter?

Answer

Applications are expected to include: 1. integration into semiconductor testers with high-speed optical interfaces, 2. front-ends for optical measurement, and 3. evaluation of optical devices and modules.