MS32051 - 4-Ch 25Gb/s CDR+TIA Array Receiver | Macom/Microsemi
MPN: MS32051 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0 | $0.00 |
| 10 | $0 | $0.00 |
| 100 | $0 | $0.00 |
| 500 | $0 | $0.00 |
| 1,000 | $0 | $0.00 |
MS32051 Overview
A transimpedance amplifier (TIA) is a current-input, voltage-output analog front-end that converts the small photocurrent from a photodiode or ROSA into a differential voltage suitable for high-speed decision circuits. A Clock and Data Recovery (CDR) block then retimes the signal to a clean reference clock, reducing deterministic jitter accumulated across the optical and electrical paths. Combining the TIA and CDR in a single ASIC (the MS32051 belongs to the IC / integrated circuit taxonomy: optical IC -> transceiver IC -> mixed-signal IC -> semiconductor) allows module designers to drop four receive lanes onto one die, cutting BOM count, board area, and power compared with discrete TIA + CDR designs.
Key features include integrated 4-channel TIA with typical input-referred noise suitable for ROSA modules, on-die CDR supporting 24-28 Gb/s retimed operation, CDR bypass for legacy 10 Gb/s lanes, per-channel loss-of-signal (LOS) indication, and an I²C / 4-wire digital control interface for setup, monitoring, and rate switching. Differential CML-compatible output drivers deliver sub-UI jitter performance required by IEEE 802.3bm / 100GBASE-SR4 links.
Typical applications include QSFP28, QSFP-DD, and CFP-style parallel optical transceivers for data-centre switches, 100G / 400G client-side optics, OTU4 telecom line cards, and breakout 4×10G / 4×25G AOC / AOI assemblies. Placing the MS32051 between the photodiode array and the module's host-side DSP or switch ASIC also reduces clock routing complexity.
When designing with the MS32051, treat the high-speed differential outputs as 100-Ω matched pairs and route them on a continuous reference plane; consult the manufacturer datasheet for thermal-coupling and supply-decoupling guidelines. CDR bypass mode must be selected via the digital interface before low-rate traffic is forwarded to avoid false lock to pattern-dependent edges.
Drop-in alternatives for MS32051 — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
MS32052
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
MS32050
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
MS32051 Maximum Ratings & Electrical Characteristics
| Product Type | 4-Channel Optical Array Receiver with Integrated CDR and TIA |
| Channels | 4 (quad) |
| Data Rate (CDR active) | 24 Gb/s to 28 Gb/s per channel |
| Data Rate (CDR bypass) | Up to 10 Gb/s per channel |
| Integrated Blocks | TIA + CDR per channel (4x) |
| Input Stage | Transimpedance Amplifier (TIA) for ROSA / photodiode interface |
| Output Stage | Differential CML-compatible drivers (100-Ω matched) |
| Target Module Form Factor | QSFP28-style optical modules |
| Target Standard | 100 Gb/s / 4×25 Gb/s / 4×10 Gb/s optical links |
| Digital Control | I²C / 4-wire configuration and monitoring interface |
| CDR Bypass Mode | Yes - selectable for 10 Gb/s non-retimed operation |
| Loss-of-Signal (LOS) Indicator | Per-channel |
| Compliance (inferred) | Designed for IEEE 802.3bm / 100GBASE-SR4 class links |
| RoHS Status | unknown |
MS32051 standard Pin Configuration Guide
Pin configuration for MS32051 (standard package). This analog component features input, output, and power supply pins. Refer to the manufacturer datasheet for offset null, compensation, and enable pin configurations. Ideal for signal conditioning and amplifier circuits.
No detailed pinout data available for MS32051.
Refer to the datasheet for full pin configuration.
Typical Applications
MS32051 is suitable for 6 applications: QSFP28 100G SR4 Optical Modules, QSFP-DD and 400G Breakout Modules, Active Optical Cables (AOC) and AOI Assemblies, OTU4 Telecom Line Cards, Datacenter Top-of-Rack Switch Optics, Test and Measurement Optical Probe Heads.
QSFP28 100G SR4 Optical Modules
The MS32051's 4-channel TIA+CDR integration maps directly to the four lanes of a QSFP28 100GBASE-SR4 module, where each lane carries 25 Gb/s NRZ data from a ROSA photodiode array. Each integrated TIA provides the wide-bandwidth amplification required to convert ROSA photocurrent into differential CML, while each on-die CDR recovers a clean clock and retimes the data to remove pattern-dependent jitter before it reaches the module's host connector. With a single IC replacing eight discrete parts, the MS32051 enables power budgets consistent with QSFP28 module maximums and helps maintain the tight eye-mask required by IEEE 802.3bm. The CDR-bypass path supports 4×10 Gb/s legacy links in the same hardware, allowing modules to be firmware-reconfigured between 100G and 40G rate sets.
Recommended
QSFP-DD and 400G Breakout Modules
For QSFP-DD and breakout modules the MS32051's per-lane CDR range of 24-28 Gb/s lines up cleanly with 50G PAM4 building blocks when two lanes are aggregated externally. As a quad receiver, it can serve as the optical front-end for 4×25 Gb/s retimed breakout paths or as the inner quad of an 8×25 Gb/s 200G design with two ICs. The on-die loss-of-signal (LOS) outputs feed directly to the module's microcontroller for fast rate-switch and fault response. Designers value the integrated CDR because it removes 16 distinct high-speed traces (4 TIA-out + 4 CDR-in pairs) from the module PCB.
Recommended
Active Optical Cables (AOC) and AOI Assemblies
The MS32051 is well matched to active optical cable (AOC) and active optical input (AOI) assemblies that need a compact, low-power 4-channel optical receiver with retiming. Because AOCs are pre-terminated and pre-tested, deterministic retiming by the integrated CDR helps the cable pass stringent bit-error-rate tests across temperature. CDR-bypass mode lets the same hardware negotiate to 4×10 Gb/s links on legacy 40G switches. The 4-channel density also reduces module weight and BOM count, which matter in high-density top-of-rack cabling.
Recommended
OTU4 Telecom Line Cards
OTU4 client optics require 4×28 Gb/s retimed output, exactly the operating envelope of the MS32051's CDR-enabled mode. Telecom-grade modules typically apply the OTU4 frame and FEC in a companion framer, but rely on the receiver for clean clock recovery and deterministic jitter—functions the MS32051 delivers on each lane independently. With CDR-bypass available, a single module type can also serve OTU2/OTU3 10G-handoff ports, simplifying sparing for telecom operators. Always validate the part against your carrier's ITU-T G.709 conformance and wander requirements before deployment.
Recommended
Datacenter Top-of-Rack Switch Optics
Hyperscale datacenter top-of-rack switches use large populations of QSFP28 ports, where 4-channel TIA+CDR arrays like the MS32051 simplify board layout and reduce per-port power. With the MS32051 handling retiming per port, switch ASICs can dedicate their internal resources to traffic policing and queueing rather than signal conditioning. CDR-bypass allows mixed 25G and 10G server uplinks without changing module hardware, easing transition from 10G to 25G server fabrics. Combined with the per-channel LOS, the switch's baseboard management can quickly identify failing optics.
Recommended
Test and Measurement Optical Probe Heads
High-speed optical probe heads in T&M equipment benefit from the MS32051's integrated TIA+CDR because they can deliver retimed, low-jitter electrical outputs to the instrument's BERT or oscilloscope. With four lanes on one die, a single probe head can capture aggregate 100 Gb/s traffic while staying inside a compact enclosure with limited heat dissipation. The independent LOS outputs double as the optical-loss alarm for the instrument frontend. Designers should use the I²C/4-wire interface to set per-channel equalizer taps and verify compliance margin during manufacturing test.
Recommended
Recommended Products Summary
Engineering reference data for MS32051 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MS32052 | MS32050 |
|---|---|---|---|
| Brand | MACOM Technology Solutions | MACOM Technology Solutions | MACOM Technology Solutions |
| Channels | 4 | 4 | 4 |
| Data Rate (CDR bypass) | 10 Gb/s | 10 Gb/s | 10 Gb/s |
| Integrated TIA | Yes (per channel) | Yes | Yes |
| Integrated CDR | Yes (per channel) | Yes | Yes |
| Target Module Form Factor | QSFP28 | QSFP28 | QSFP28 |
| Per-Channel LOS | Yes | Yes | Yes |
Key Differentiators
- Integrated CDR per lane enables retimed 25-28 Gb/s output without external retimers (vs MS32050)
- CDR-bypass mode supports legacy 10 Gb/s modules in the same hardware (vs MS32052)
- Quad-channel integration reduces BOM count and inter-stage trace length (vs MS32050)
Design Notes
Route the four TIA inputs and four CDR outputs as 100-Ω differential pairs on a continuous reference plane to limit impedance discontinuities. Each differential pair should be length-matched within 0.1 mm of its lane-mates to keep intra-module skew well below one UI at 28 Gb/s. A recommended PCB stack-up is documented in the manufacturer's reference design and should be followed verbatim for first-pass success.
Decouple each supply pin with its own 100 nF X7R capacitor placed as close to the ball as possible; add a bulk 1 µF / 10 µF bypass per voltage domain within 5 mm. Switching transients from the CDR's internal PLL can alias into the analog front-end if supplies are shared without ferrite beads. Keep noisy switching converters away from the IC's analog supply pin and its corresponding ground return.
Do not enable CDR-bypass mode while running 25 Gb/s traffic - the bypass path lacks the high-bandwidth decision circuit needed at that rate, and the eye diagram will fail IEEE 802.3bm masks. Always select the operating mode (retimed 25G vs. bypassed 10G) via the digital interface before sending real traffic, and verify with BERT that LOS reads clean on each lane. Estimated: assuming BER target 1e-12 across 4 lanes at 28 Gb/s, expect < 1 LOS toggle per 24 hours under nominal fiber conditions.
The MS32051 dissipates non-trivial power because each lane runs both a TIA and a CDR. In a sealed QSFP28 housing, ensure the module PCB thermal vias under the package reach the housing heatsink for proper airflow coupling. Use the manufacturer's derating curve if the module will operate above 70 °C case temperature, as the CDR's jitter performance degrades with temperature. Estimated: each TIA+CDR lane is expected to consume ~250-350 mW, so the full quad is ~1.0-1.4 W before supplies.
Compliance Information
Optical IC destined for datacenter and telecom use; manufacturer compliance details to be confirmed directly with MACOM Technology Solutions.
