Renesas GX39220-DNT

Overview

GX39220-DNT from Renesas Electronics is a dual-channel 96Gbaud linear trans-impedance amplifier (TIA) designed for integrated coherent receivers (ICRs) in 800G+ optical systems. It delivers differential gain from 50–3,250Ω, >60GHz adjustable 3dB bandwidth, >30dB VGA dynamic range, and output clipping at 900mVppd, serving as the front-end analog signal conditioner for I/Q photodiode currents in CFP2/CFP4 modules.

For engineers reviewing the GX39220-DNT datasheet, GX39220-DNT pinout, GX39220-DNT application, or GX39220-DNT equivalent, this page provides verified technical context on its AGC/ATC architecture, bandwidth control via BWCA/B pins, peak detection (OMON), shutdown (SHDB), and RF input/output pad layout - all critical for high-order QAM coherent receiver design and die-level integration.

Technical Context

The GX39220-DNT implements two independent TIA signal paths with single-ended photodiode inputs (INxP/INxN), automatic threshold control (ATC) for DC offset cancellation, and a CML-compatible differential output stage. Each channel supports both automatic gain control (AGC) and manual gain control (MGC) modes selected via GCS, with VGCx serving as gain control input (MGC) or gain monitor output (AGC).

Bandwidth is digitally adjusted across nine settings (57–73GHz) using BWCA/B voltage combinations; output amplitude is regulated via VOAx; and peak-to-peak swing is monitored via OMONx. The die integrates on-chip RC filtering on VPDSx pads and maintains isolation between input (GND) and output (GNDO) grounds to minimize crosstalk (<−40dB up to 60GHz).

Key Specifications

Pinout & Package

GX39220-DNT is supplied as a bare die measuring 1845 ±30μm × 1515 ±30μm × 100 ±15μm, with aluminum bond pads (4μm thick) and 125μm pad pitch. RF input/output pads are 70μm × 90μm; DC pads are 120μm × 70μm. Input and output grounds (GND/GNDO) are isolated on-die.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar linear TIA applications.

Compared with MAX3748AETE+T and HMC1090LP5E, the GX39220-DNT uniquely delivers dual-channel 96Gbaud linear amplification with on-die AGC, ATC, bandwidth tuning, and photodiode biasing - making it the only qualified solution for CFP2/CFP4-integrated coherent receivers requiring sub-5ps I/Q skew and >30dB dynamic range.

Availability

GX39220-DNT is available at Aetrix Electronics and suitable for 800G optical transceivers, integrated coherent receivers, and high-order QAM test equipment requiring stable component supply, controlled die-level sourcing, and long-term lifecycle support.

Supply support for GX39220-DNT includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Renesas Electronics is a global semiconductor leader specializing in microcontrollers, analog, power, and connectivity solutions for automotive, industrial, and data infrastructure markets.

The GX39220-DNT belongs to Renesas' high-speed optical interconnect product line, engineered specifically for die-level integration into 800G+ coherent optical modules with emphasis on bandwidth scalability, low-noise linearity, and system-level configurability.

FAQ

What is the operating temperature range for the GX39220-DNT?

The GX39220-DNT is rated for operation from −5°C to +95°C, matching the thermal envelope of CFP2 and CFP4 optical modules. This range is validated under recommended supply conditions (VCC = 3.07–3.47V) and accounts for die self-heating at maximum power dissipation (720mW). Thermal derating is not required within this span, and the device maintains specified gain, bandwidth, and noise performance across the full range.

Does the GX39220-DNT support automatic gain control (AGC) and manual gain control (MGC) simultaneously?

No - the GX39220-DNT supports either AGC or MGC per channel, selected globally via the GCS pin. When GCS is high or floating, both channels operate in AGC mode; when GCS is low, both enter MGC mode. VGCx serves as gain control input in MGC mode and as gain monitor output in AGC mode. Simultaneous mixed-mode operation is not supported.

How is bandwidth adjusted on the GX39220-DNT?

Bandwidth on the GX39220-DNT is adjusted digitally using two voltage-controlled inputs: BWCA and BWCB. Each accepts three logic levels (Low: 0–0.9V, Mid: 1.1–1.8V, High: 2–3.3V), producing nine distinct peaking settings from 57.2GHz (min) to 73.3GHz (max). Floating pins default to mid-level (1.5V), yielding ~66GHz typical bandwidth. No external components are needed beyond proper decoupling.

What is the purpose of the OMONx pins on the GX39220-DNT?

The OMONx pins on the GX39220-DNT provide analog DC voltage outputs proportional to the average absolute value of the peak-to-peak differential output swing (Vout). This peak detection function enables real-time signal health monitoring, closed-loop gain calibration, and automatic threshold adjustment in coherent receiver systems. Typical OMON output ranges from 0.5V to 2.7V depending on Vout magnitude.

Can the GX39220-DNT be used with single photodiodes instead of balanced configurations?

Yes - the GX39220-DNT supports single photodiode configuration per channel: the photodiode anode connects to INxP, and the cathode connects to VPDx (with VPDSx supplying filtered bias). In this mode, INxN is left unconnected. Performance remains within specification, though common-mode rejection and DC offset cancellation are reduced compared to balanced operation. The datasheet explicitly confirms this configuration in Pad Descriptions and Assembly Notes.