GX39221-DNT - 96Gbaud 2-Ch Linear TIA | Renesas | 800G Coherent
MPN: GX39221-DNT ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $125.36 | $125.36 |
| 10 | $119.09 | $1,190.90 |
| 100 | $112.82 | $11,282.00 |
| 500 | $106.56 | $53,280.00 |
| 1,000 | $100.29 | $100,290.00 |
GX39221-DNT Overview
A transimpedance amplifier is an amplifier that converts input current from a photodiode into an output voltage, characterized by gain expressed in ohms. Within the signal chain hierarchy, the TIA sits directly after the photodiode in an optical receiver, feeding subsequent linear equalizers, drivers, and analog-to-digital converters (ADCs) in the power management and telecom IC ecosystem. In coherent optical communications, linear TIAs preserve waveform linearity so that digital signal processors (DSPs) can apply chromatic dispersion compensation and advanced modulation decoding.
Key features of the GX39221 include its 96Gbaud per-channel bandwidth class, dual-channel integration for I and Q polarization-multiplexed coherent detection, linear (non-limiting) transfer characteristics essential for coherent DSP-based receivers, and a low-power, compact design suited to SFF modules. Integration of two signal paths reduces part count and simplifies alignment in CFP2 and CFP4 module designs.
Technically, the GX39221 targets integrated coherent receiver architectures where photodiode photocurrent from coherent detection is amplified with high linearity at extreme symbol rates. Linear TIAs at 96Gbaud require high transimpedance gain, low noise, wide bandwidth, and output swing matched to downstream linear equalizers. The GX39221-DNT variant suffix denotes a specific package/packing configuration per Renesas ordering codes.
Typical applications include 800G and beyond coherent transceivers, integrated coherent receivers (ICRs), CFP2-DCO and CFP4 optical modules, and data center interconnect (DCI) links. The dual-channel structure directly matches the I/Q detection scheme of polarization-multiplexed coherent receivers.
Design consideration: linear TIAs for coherent receivers demand careful RF layout, matched differential routing, and impedance control between the photodiode, TIA, and downstream linear equalizer; consult the manufacturer datasheet for the exact differential output interface and supply requirements.
This page synthesizes distributor pricing from LCSC, DigiKey, and Mouser, datasheet availability, and application context not found on any single distributor page.
Drop-in alternatives for GX39221-DNT — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
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Request AlternativesGX39221-DNT Specifications
| Product Type | Linear Transimpedance Amplifier (TIA) |
| Channels | 2 (I and Q signal paths) |
| Baud Rate | 96 Gbaud per channel |
| Linearity | Linear (non-limiting) |
| Target Application | 800G and beyond integrated coherent receivers (ICRs) |
| Compatible Module Formats | CFP2, CFP4 (SFF optical modules) |
| Mounting Type | Surface Mount |
GX39221-DNT standard Pin Configuration Guide
Pin configuration for GX39221-DNT (standard package). Pin numbering, functions, and connection diagrams are defined in the manufacturer datasheet. Refer to it for the exact footprint and soldering guidelines.
No detailed pinout data available for GX39221-DNT.
Refer to the datasheet for full pin configuration.
Typical Applications
GX39221-DNT is suitable for 6 applications: 800G Integrated Coherent Receiver (ICR), CFP2-DCO Coherent Optical Modules, CFP4 Small Form Factor Optical Modules, Data Center Interconnect (DCI) Links, Telecom Test and Measurement Optical Front Ends, 800G ZR/ZR+ Pluggable Transceivers.
800G Integrated Coherent Receiver (ICR)
The GX39221-DNT is purpose-built for 800G and beyond integrated coherent receivers, where photodiode photocurrent from coherent detection must be amplified with high linearity before DSP-based equalization. Its two integrated 96Gbaud linear TIA paths map directly onto the I and Q detection channels of polarization-multiplexed coherent detection, eliminating the need for two discrete TIAs. Because a linear TIA preserves amplitude information, the downstream DSP can apply chromatic dispersion compensation and advanced modulation decoding. The compact, low-power design supports the thermal and dimensional budget of modern ICR subassemblies.
Recommended
CFP2-DCO Coherent Optical Modules
CFP2-DCO modules pack a coherent receiver, DSP, and analog front end into a very small form factor, making dual-channel TIA integration essential. The GX39221-DNT's two 96Gbaud linear channels replace two discrete TIAs, saving board area and reducing channel-to-channel mismatch that would otherwise degrade DSP equalization performance. Its low-power operation helps stay within the CFP2 thermal envelope. The linear transfer characteristic preserves I/Q amplitude fidelity for coherent demodulation at 800G line rates, and the compact Renesas design supports dense DCI line-card deployment.
Recommended
CFP4 Small Form Factor Optical Modules
In CFP4 modules the area budget is even tighter than CFP2, so Renesas specifically designed the GX39221 family for SFF formats including CFP4. The dual-channel integration of the I and Q TIA paths shortens the RF routing between photodiodes and the amplifier, which reduces parasitic capacitance and preserves the 96Gbaud bandwidth margin. Low power dissipation simplifies heat spreading in the module housing. Designers should follow the datasheet layout guidance for impedance-controlled differential outputs into the downstream linear equalizer and ADC driver chain.
Recommended
Data Center Interconnect (DCI) Links
800G coherent DCI links between data centers rely on integrated coherent receivers whose noise and linearity set the achievable optical power budget and reach. The GX39221-DNT's 96Gbaud linear channels provide the receiver front-end gain for coherent demodulation of high-order modulation formats used at 800G. Its low-noise linear amplification allows the downstream DSP to extract maximum performance from weak received signals, extending reach. The low-power, compact design suits high-port-count DCI line cards where hundreds of receiver channels share a chassis thermal budget.
Recommended
Telecom Test and Measurement Optical Front Ends
Optical test instruments and coherent lightwave analyzers require linear receive chains that faithfully reproduce I/Q waveforms for constellation analysis. The GX39221-DNT's linear (non-limiting) 96Gbaud channels make it suitable for wideband optical front ends in 800G-class measurement setups. Preserving amplitude linearity is essential when measuring modulation quality metrics such as error vector magnitude. Its dual-channel integration keeps the two polarization axes matched, which improves measurement repeatability. Engineers should validate gain flatness and noise against the Renesas datasheet for instrument-grade calibration.
Recommended
800G ZR/ZR+ Pluggable Transceivers
The 800G ZR and ZR+ pluggable ecosystem brings coherent technology into compact QSFP-DD and OSFP form factors, driving demand for highly integrated, low-power analog front ends. The GX39221-DNT's dual 96Gbaud linear TIA channels and compact Renesas design address the aggressive power and area limits of these pluggables. Linear amplification preserves the I/Q information needed for DSP-based 800G coherent transmission. When designing pluggable receivers, engineers must carefully budget the power dissipation and follow the datasheet's RF layout recommendations for photodiode-to-TIA interconnect.
Recommended
Engineering reference data for GX39221-DNT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product |
|---|---|
| Brand | Renesas Electronics |
| Channels | 2 (I and Q) |
| Baud Rate | 96 Gbaud per channel |
| Linearity | Linear (non-limiting) |
| Target Application | 800G+ ICR, CFP2/CFP4 |
| Unit Price (qty 1) | $125.36 (as of 2026-09-14, LCSC) |
| Lifecycle Status | Active |
Key Differentiators
- Dual-channel integration for I/Q coherent detection (vs discrete single-channel TIAs)
- Purpose-built linear (non-limiting) architecture (vs limiting TIAs)
- Compact, low-power SFF design (vs larger-footprint receiver front ends)
Design Notes
In a 96Gbaud linear TIA channel, the photodiode-to-TIA interconnect dominates bandwidth performance. Keep the photodiode bonding/packaging parasitic capacitance to the minimum the optical subassembly allows, use short, impedance-controlled differential output traces to the linear equalizer, and maintain matched channel lengths for I and Q so downstream DSP equalization sees symmetric channel responses. Any asymmetry between channels directly degrades polarization-multiplexed demodulation performance in the ICR.
Because the GX39221 targets compact CFP2/CFP4 modules, supply decoupling and power integrity are critical at 96Gbaud signal speeds. Place low-ESR decoupling capacitors close to each supply pin per the datasheet's typical application circuit, and separate the sensitive analog supply domain from other switching loads in the module (DSP core rails, laser drivers). Estimated: even modest supply ripple can couple into the linear output and raise the effective noise floor of the coherent receiver.
Do not use this linear TIA in direct-detection (IM/DD) applications expecting digital-level output - it is a linear part designed to feed an ADC/DSP chain, so its output will not saturate to logic levels. Also, the exact electrical specifications (supply voltage, gain, noise) must be taken from the official Renesas datasheet for the DNT ordering suffix; distributor listings do not expose these parameters, and designing from assumptions risks a non-functional front end.
Compliance Information
Compliance declarations were not present in the retrieved distributor data. Verify on the official Renesas GX39221 product page or request the material declaration sheet.
