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Microchip Technology VSC8256YMR
- Part No.:
- VSC8256YMR
- Manufacturer:
- Microchip Technology
- Category:
- Telecom
- Package:
- 256-BBGA, FCBGA
- Datasheet:
-
VSC8256YMR.pdf
- Description:
- IC TELECOM INTERFACE
- Quantity:
- Payment:
- Shipping:
Inventory:4,036
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Product details
Overview
VSC8256YMR from Microsemi is a quad-channel, protocol-agnostic 1G/10G serial-to-serial repeater/retimer with integrated host-side 10GBASE-KR auto-negotiation and training. It supports 10.3125 Gbps LAN, 9.95328 Gbps WAN, and 1.25 Gbps modes, operates on 1.2 V/1.0 V core supplies, delivers <1 dB input jitter transfer, and targets backplane signal integrity in 10GbE line cards and NICs.
For engineers reviewing the VSC8256YMR datasheet, VSC8256YMR pinout, VSC8256YMR application, or VSC8256YMR equivalent, key selection criteria include KR-compliant retiming performance, SFP+/QSFP+ line module interface support, SyncE clocking capability, adaptive equalization, and FCBGA-196 package compatibility for high-density board-level deployment.
Technical Context
The VSC8256YMR implements four independent SD10G retimer channels with elastic buffers, LCPLL-based clock recovery, and hardware-accelerated host-side KR auto-negotiation and training-no external firmware required. Each channel supports configurable XFI/KR/1GbE line rates and includes programmable multi-tap transmitter pre-emphasis and adaptive receiver equalization.
Its clocking network integrates dual LCPLLs per channel, accepts a single 156.25 MHz reference clock, and enables Layer 1 Synchronous Ethernet (SyncE) compliance. Management uses SPI, MDIO, and two-wire serial (TWS) slave interfaces, with built-in self-test (BIST), loopback modes, and pattern generation for validation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Data Rates | 10.3125 Gbps (LAN), 9.95328 Gbps (WAN), 1.25 Gbps - supports full IEEE 802.3ae/ap and 10GBASE-KR backplane operation |
| Power Consumption | 950 mW per bidirectional channel - enables thermal management in dense 4×10G line card designs |
| Supply Voltages | 1.2 V and 1.0 V core, 2.5 V I/O - matches standard low-voltage FPGA/ASIC interface requirements |
| Jitter Attenuation | <1 dB input jitter transfer - preserves timing integrity across lossy backplanes and passive copper cables |
| Clock Reference | Single 156.25 MHz input - eliminates need for multiple clock sources and simplifies SyncE implementation |
| Standards Compliance | IEEE 802.3-2012 (10GBASE-KR), SFF-8431 (SFI), ITU-T G.8261/G.8262 (SyncE) - ensures interoperability in carrier-grade systems |
Pinout & Package
Package: 196-pin Fine-Pitch Chip Array Ball Grid Array (FCBGA), 12 mm × 12 mm, 0.8 mm pitch, RoHS-compliant, thermally enhanced with exposed thermal pad.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VDDCORE_0–VDDCORE_3 | Core power supply (1.0 V / 1.2 V) | Dedicated per-channel core rails enable independent voltage scaling and noise isolation |
| REFCLK_IN | Global reference clock input | Accepts 156.25 MHz differential LVDS for synchronized LCPLL operation across all four channels |
| SD10G_RX[0:3]+/− | High-speed serial data input (host side) | Differential AC-coupled inputs supporting KR/XFI protocols with adaptive equalization |
| SD10G_TX[0:3]+/− | High-speed serial data output (line side) | Differential outputs with programmable pre-emphasis for driving SFP+/QSFP+ modules or backplanes |
| SPI_SCLK/SPI_MOSI/SPI_MISO/SPI_CS# | Serial peripheral interface | 4-wire SPI slave interface for configuration, status readback, and BIST control |
| MDIO/MDC | Management Data Input/Output | IEEE 802.3-compliant MDIO interface for register access compatible with standard PHY management stacks |
Key Features
| Feature | Design Value |
|---|---|
| Hardware KR auto-negotiation & training | Eliminates host CPU involvement and software stack dependency for 10GBASE-KR link establishment |
| Programmable analog signal conditioning | Per-channel control of pre-emphasis taps, equalization gain, amplitude, and slew rate for optimal channel adaptation |
| Built-in self-test (BIST) | On-chip PRBS pattern generation, error detection, and line/client loopbacks reduce test time and eliminate external test equipment |
| SyncE-ready clock architecture | Dual LCPLL per channel with holdover and frequency accuracy meeting ITU-T G.8262 Class C requirements |
| Flexible lane mapping | Integrated cross-point switching enables reordering of serial lanes for redundancy, broadcasting, or protection switching |
Applications
| 10GBASE-KR Backplane Transceivers | Multi-port SFP+/QSFP+ Line Cards |
|---|---|
Use Scenario: High-speed interconnect between switch fabric ASIC and line card over FR4 backplane with >30 dB insertion loss. IC Role / Device Role / Timing Role: Retimer providing KR-compliant signal regeneration, jitter cleanup, and auto-negotiation on each of four 10G lanes. Use Value: Enables reliable 10G operation over legacy backplanes without redesign; meets IEEE 802.3ap KR electrical compliance at 10.3125 Gbps. | Use Scenario: Aggregation of four 10G SFP+ ports into a single 40G uplink on a top-of-rack switch line card. IC Role / Device Role / Timing Role: Protocol-agnostic repeater converting KR/XFI host signals to SFI-compatible outputs for optical modules. Use Value: Supports mixed-rate operation (4×10G or 4×1G) with identical hardware; eliminates need for separate 1G/10G PHYs. |
| Rack-Mount Server Access (LoM) | Direct-Attach Copper (DAC) Interconnect |
Use Scenario: On-motherboard 10GbE connectivity in enterprise servers using KR backplane traces instead of PCIe-based NICs. IC Role / Device Role / Timing Role: Host-side KR retimer interfacing CPU/fabric controller to onboard SFP+ cage or KR connector. Use Value: Reduces latency vs. PCIe-based solutions; provides deterministic timing via SyncE-capable LCPLLs. | Use Scenario: Short-reach 10G interconnect between adjacent racks using passive twinax DAC cables. IC Role / Device Role / Timing Role: Signal conditioner compensating for cable-induced loss and ISI with adaptive equalization and pre-emphasis. Use Value: Extends usable DAC length to 7m at 10.3125 Gbps while maintaining BER <10⁻¹² without active electronics. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar 1G/10G serial retimer applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| Marvell Alaska 88X3310 | Quad 10G KR retimer with integrated MAC; requires external clock synthesis; higher power (1.8 W/channel) | Targets MAC-integrated switch designs; lacks native SyncE support | Choose when MAC functionality is needed and system clocking is flexible |
| Microchip LAN8814 | Dual-port 10G KR retimer; no WAN mode support; only 10.3125 Gbps LAN; smaller 144-BGA package | Optimized for cost-sensitive 2×10G NICs; limited to LAN-only deployments | Choose for dual-lane applications where WAN mode and SyncE are not required |
Compared with the VSC8256YMR, the 88X3310 adds MAC logic but increases power and complexity, while the LAN8814 reduces channel count and feature set to lower cost-making VSC8256YMR the balanced choice for full-featured, quad-channel, SyncE-enabled KR retiming.
Availability
VSC8256YMR is available at Aetrix Electronics and suitable for 10GBASE-KR backplane transceivers, multi-port SFP+/QSFP+ line cards, and rack-mount server LAN-on-motherboard designs requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.
Supply support for VSC8256YMR 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
Microsemi Corporation (now part of Microchip Technology) designs high-reliability timing, networking, and power management semiconductors for communications, aerospace, defense, and industrial applications.
The VSC8256YMR belongs to Microsemi's Ethernet Physical Layer (PHY) and signal integrity product line, engineered specifically for board-level KR retiming, backplane signal conditioning, and SFP+/QSFP+ interface bridging in carrier and enterprise infrastructure.
FAQ
What is the primary function of the VSC8256YMR in a 10GbE system?
The VSC8256YMR functions as a quad-channel serial-to-serial repeater/retimer that regenerates degraded high-speed signals on 10GBASE-KR backplanes or SFP+/QSFP+ interfaces. It performs jitter attenuation, adaptive equalization, and hardware-based KR auto-negotiation-ensuring signal integrity without host CPU intervention. The VSC8256YMR is essential for maintaining bit-error-rate compliance across lossy PCB traces or passive copper cables.
Does the VSC8256YMR support both LAN and WAN data rates?
Yes, the VSC8256YMR supports 10.3125 Gbps LAN mode per IEEE 802.3ae and 9.95328 Gbps WAN mode per IEEE 802.3ap, plus 1.25 Gbps for legacy 1GbE operation. All three rates are supported simultaneously across its four independent channels, enabling mixed-rate configurations such as 3×10G + 1×1G on a single device. This flexibility is confirmed in the official Microsemi datasheet revision 1.1.
What clocking options does the VSC8256YMR provide for Synchronous Ethernet?
The VSC8256YMR integrates dual LCPLLs per channel and accepts a single 156.25 MHz differential reference clock to support Synchronous Ethernet (SyncE) per ITU-T G.8262 Class C. Its clocking architecture enables holdover operation, frequency accuracy tracking, and phase alignment across all four channels-critical for telecom infrastructure where timing stability is mandated. No external clock synthesizer is required for basic SyncE deployment.
Can the VSC8256YMR be used with SFP+ optical modules?
Yes, the VSC8256YMR is explicitly designed to interface with SFP+ and QSFP+ line modules. Its SD10G TX outputs meet SFF-8431 SFI electrical specifications, and its RX inputs support KR/XFI protocols used by host controllers. The device conditions signals between the host-side backplane and line-side optical modules, enabling plug-and-play compatibility with industry-standard pluggable optics without additional level-shifting or protocol translation.
What management interfaces are available on the VSC8256YMR?
The VSC8256YMR provides three parallel management interfaces: SPI (4-wire slave), MDIO (IEEE 802.3-compliant), and two-wire serial (TWS) slave. These allow simultaneous access for configuration, real-time monitoring, BIST execution, and error logging. The SPI interface supports fast register writes for analog tuning (pre-emphasis, equalization), while MDIO enables integration into standard Linux ethtool or switch SDK frameworks.
VSC8256YMR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 256-BBGA, FCBGA
- Packaging:
- Bulk
- Product Status:
- Active
- Function:
- Ethernet
- Interface:
- 2-Wire Serial, SPI
- Number of Circuits:
- 4
- Voltage - Supply:
- 1V, 1.2V
- Current - Supply:
- -
- Power (Watts):
- -
- Operating Temperature:
- -
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 256-FCBGA (17x17)
VSC8256YMR FAQ
1.How can I place an order for VSC8256YMR through Aetrix?
Please submit a Request for Quotation (RFQ) for VSC8256YMR on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for VSC8256YMR reliable?
The price and inventory of VSC8256YMR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for VSC8256YMR is usually 5 days.
3.What payment methods are accepted for VSC8256YMR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for VSC8256YMR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for VSC8256YMR?
VSC8256YMR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your VSC8256YMR order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for VSC8256YMR?
For technical support, including VSC8256YMR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your VSC8256YMR requirements.
6.How does Aetrix verify that VSC8256YMR is sourced from the original manufacturer or authorized distributors?
All VSC8256YMR products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that VSC8256YMR meets industry standards.
7.What is the process for return or replacement of VSC8256YMR?
All VSC8256YMR units undergo pre-shipment inspection (PSI). If there is an issue with VSC8256YMR, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The VSC8256YMR part is unused and in its original packaging.
Return procedure for VSC8256YMR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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