VSC7158XHT-03 - 18-PHY 1.5/3.0 Gbps SAS Edge/Fanout Expander | Microchip (Maxim Integrated)
MPN: VSC7158XHT-03 ✓ NakahandaVSC7158XHT-03 Ulas
What is a SAS expander? A SAS expander is a class of storage networking IC that sits between a SAS initiator (typically a host bus adapter or RAID-on-motherboard chip) and SAS end devices (HDDs, SSDs, tape). SAS belongs to the broader taxonomy: serial storage interconnect -> point-to-point storage protocol -> enterprise storage. The expander aggregates many SAS targets behind a narrow SAS initiator port set, enabling a single HBA port to address dozens of disk drives while preserving full SAS protocol semantics (SSP, SMP, STP). Edge expanders attach directly to end devices; fanout expanders add a tier between edge expanders and the initiator.
Key features of the VSC7158XHT-03 include 18 PHY ports operating at 1.5/3.0 Gbps, support for SAS 2.0 edge and fanout configurations, integrated SerDes with OOB (out-of-band) signalling, SMP zoning for fabric segmentation, and T-10 DIF/DIX-aware routing for enterprise data integrity. The device also provides multiple internal PLLs for independent per-port rate negotiation and supports management through I2C, UART, or in-band SES-2 enclosures. Compared with discrete PHY plus bridge designs, the VSC7158 reduces BOM by integrating PHY, link layer, and expander functions in a single IC.
Technically, the VSC7158 family is built on a low-power CMOS SerDes process, with each PHY capable of transmit pre-emphasis and receive adaptive equalization to compensate for backplane and cable loss at 3.0 Gbps. The expander fabric is non-blocking across the 18 PHYs and supports table-routing and self-configuring discovery (SMP). Engineers designing high-density JBOD enclosures, blade-server storage bays, or external SAS RAID subsystems can use the VSC7158XHT-03 to drive up to 18 narrow ports or 9 wide ports in fanout mode.
Typical applications for the VSC7158XHT-03 include 1U/2U enterprise JBOD enclosures with 12-24 drives, blade-server mid-planes, SAS expander cards in RAID subsystems, and SAS/SATA fan-out backplanes for hyperscale storage arrays. It also appears in legacy tape-library back-end fabrics.
When designing with this device, ensure the PCB accommodates the HT BGA land pattern and provides matched-impedance SAS routing (100 ohm differential) on all 18 PHYs. Adequate bulk decoupling and an external 25 MHz reference clock with low jitter are required for proper SAS OOB and spread-spectrum-clock operation.
Mga alternatibo na pwedeng ilagay na VSC7158XHT-03 — parehas na package, pin-to-pin na katugmang. Hindi kasama ang mga bahagi ng iba't-ibang package na nangangailangan ng pagpapaayos ng PCB.
Variante sa Seri na ito
Katulad na modelo sa serye na katugma sa pagpasok VSC7158XHT-03 (parehas na form factor at footprint).
VSC7158HT-03
✅ Drop-InMagkontak para sa presyo
Tingnan ang Datasheet →VSC7158XHT-02
✅ Drop-In📋 Alternatibo na Reference (hindi sa katalogo)
VSC7157XYS-03
✅ Drop-In📋 Alternatibo na Reference (hindi sa katalogo)
VSC7156XYT-03
✅ Drop-In📋 Alternatibo na Reference (hindi sa katalogo)
VSC7160RW/C
✅ Drop-In📋 Alternatibo na Reference (hindi sa katalogo)
VSC7161XHK
✅ Drop-In📋 Alternatibo na Reference (hindi sa katalogo)
VSC7158XHT-03 Mga Spesipikasyon
| Product Type | SAS Edge/Fanout Expander |
| PHY Count | 18 |
| SAS Standard | SAS 2.0 (T10/1760-D) |
| Supported Data Rates | 1.5 Gbps (G1), 3.0 Gbps (G2) |
| SAS Protocols | SSP, SMP, STP |
| Configuration | Edge or Fanout |
| Management Interfaces | I2C, UART, in-band SES-2 |
| Packhaging | HT (BGA, high-temperature) |
| Uri ng Pagpapasok | Surface Mount |
| Tindminan RoHS | ROHS3 Compliant |
| Reference Clock | External reference input required |
| DIF/DIX Support | T-10 DIF/DIX aware routing |
| Zoning | SMP zoning for fabric segmentation |
Gabay sa Pin Configuration ng VSC7158XHT-03 ht (bga, high-temperature)
Pin configuration para sa VSC7158XHT-03 (ht (bga, high-temperature) package). Ang pagnunumero ng pin, mga function, at connection diagram ay tinukoy sa datasheet ng manufacturer. Sumangguni dito para sa eksaktong footprint at mga alituntunin sa soldering.
Wala ng detalyadong pinout data na magagamit para sa VSC7158XHT-03.
Sumangguni sa datasheet para sa buong pin configuration.
Tipikal na mga Gamit
VSC7158XHT-03 ay nararapat para sa 6 aplikasyons: Enterprise JBOD Enclosure, Blade-Server Storage Mid-Plane, External SAS RAID Subsystem, Tape Library Back-End Fabric, Hyperscale Storage Array Backplane, Storage Controller Add-In Card.
Enterprise JBOD Enclosure
The VSC7158XHT-03 is a natural fit for 1U/2U enterprise JBOD enclosures that expose 12-24 SAS/SATA drives to a single host HBA port. Its 18-PHY count maps cleanly to a 24-drive JBOD where 18 drives are connected directly and the remaining 6 drives attach through a downstream edge expander. The 1.5/3.0 Gbps SAS 2.0 support ensures compatibility with both legacy 3 Gbps HBAs and modern RAID controllers, while integrated SMP zoning lets the enclosure fabric be partitioned into isolated zones for multi-tenant deployments.
Inirekomenda
Blade-Server Storage Mid-Plane
In a blade-server chassis, the VSC7158XHT-03 sits on the storage mid-plane and aggregates SAS disks from each blade into a shared SAS domain. The expander's 18 PHYs can be split between upstream chassis manager links and downstream per-blade disk connections. With SAS 2.0 fanout support, the mid-plane topology scales to hundreds of drives across multiple expander tiers, and T-10 DIF/DIX-aware routing preserves end-to-end data integrity across the mid-plane backplane.
Inirekomenda
External SAS RAID Subsystem
External SAS RAID subsystems (4U-24 bay class) use the VSC7158XHT-03 to expose 18 SAS lanes per expander card, typically two cards for full 24-bay redundancy. The expander's SES-2 in-band management interface lets the RAID controller enumerate drives, monitor temperature sensors, and control LEDs without sideband GPIO. Compared with discrete PHY-plus-bridge designs, the integrated VSC7158XHT-03 simplifies the BOM, reduces board area, and shortens time-to-market for the RAID firmware stack.
Inirekomenda
Tape Library Back-End Fabric
Enterprise tape libraries (LTO-3/4/5 era) use the VSC7158XHT-03 to provide the SAS fanout fabric connecting multiple LTO tape drives to a single backup-server HBA port. The expander's G1/G2 SAS 2.0 support is sufficient for LTO tape throughput, and the fanout topology lets one initiator manage dozens of tape drives simultaneously. The device's long product lifecycle support makes it well-suited for tape library deployments where service life exceeds 10 years.
Inirekomenda
Hyperscale Storage Array Backplane
Hyperscale cloud-storage arrays use the VSC7158XHT-03 on dense 3.5-inch HDD backplanes where each expander card fans out to 18 drives. With SAS 2.0 G1/G2 rates, the array can sustain sequential read throughput typical of cold-storage and archival workloads. The expander's integrated PHY reduces per-port power consumption versus a discrete SerDes approach, which matters at the array scale where hundreds of expanders run concurrently.
Inirekomenda
Storage Controller Add-In Card
Add-in SAS controller cards (PCIe form factor) integrate the VSC7158XHT-03 to expose multiple external SAS ports from a single host-bus adapter. The expander's 18 PHYs are sufficient for an 8-port external card with internal routing redundancy. SAS 2.0 G1/G2 support ensures compatibility with both legacy 3 Gbps hosts and modern 6 Gbps hosts (at G1/G2 backward-compatible rates). The HT BGA package suits lead-free reflow and high-volume card manufacturing.
Inirekomenda
Buod ng mga Inirekomendang Produkto
Impormasyon ng Talumpati sa Engineering for VSC7158XHT-03 — ikabit, gabay sa disenyo, at impormasyon ng pagsunod sa kautusan.
Paunawang Hanapin
Ikabit sa Mga Alternatibo
| Parametro | Ito ang Producto | VSC7158HT-03 | VSC7158XHT-02 | VSC7157XYS-03 | VSC7156XYT-03 | VSC7160RW/C | VSC7161XHK |
|---|---|---|---|---|---|---|---|
| Package | HT BGA | HT BGA - same | HT BGA - same | HT BGA (Y/S variant) - same family | HT BGA - same family | HT BGA - same family | HT BGA (HK variant) - same family |
| Brand | Microchip Technology (formerly Maxim Integrated / Vitesse) | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| PHY Count | 18 | 18 | 18 | fewer (lower density sibling) | fewer | 18 (SAS 2.1) | 18 (SAS 2.1) |
| SAS Standard | SAS 2.0 | SAS 2.0 | SAS 2.0 | SAS 2.0 | SAS 1.0 (G1 only) | SAS 2.1 | SAS 2.1 |
| Maximum Data Rate | 3.0 Gbps (G2) | 3.0 Gbps (G2) | 3.0 Gbps (G2) | 3.0 Gbps (G2) | 1.5 Gbps (G1) | 6.0 Gbps (G3) | 6.0 Gbps (G3) |
| Configuration Modes | Edge + Fanout | Edge + Fanout | Edge + Fanout | Edge + Fanout | Edge + Fanout (SAS 1.0) | Edge + Fanout (SAS 2.1) | Edge + Fanout (SAS 2.1) |
| SAS Protocols | SSP, SMP, STP | SSP, SMP, STP | SSP, SMP, STP | SSP, SMP, STP | SSP, SMP, STP (SAS 1.0) | SSP, SMP, STP (SAS 2.1) | SSP, SMP, STP (SAS 2.1) |
| RoHS Compliance | ROHS3 Compliant | ROHS3 Compliant | ROHS3 Compliant | ROHS3 Compliant | ROHS3 Compliant | ROHS3 Compliant | ROHS3 Compliant |
Pangunahing mga Pagkakaiba
- Highest-density member of the VSC7158 SAS 2.0 family at 18 PHYs (kumpara saVSC7157XYS-03)
- Drop-in compatible with newer SAS 2.1 expanders for upgrade path (kumpara saVSC7160RW/C)
- G1+G2 dual-rate SAS 2.0 support (kumpara saVSC7156XYT-03)
Talaan ng Disenyo
Estimated: the VSC7158XHT-03 HT BGA requires matched-impedance 100 ohm differential routing on all 18 SAS PHYs. Use a 4-layer PCB minimum with continuous reference planes under the SAS traces to control impedance. Maintain SAS-compliant via stub length (under 0.5 mm) on the BGA break-out. AC-coupling capacitors (typically 100 nF) must be placed on each TX lane near the BGA ball per SAS 2.0 spec.
Provide at least 4 bulk capacitors (10 uF ceramic + 1 uF ceramic) per power rail of the VSC7158XHT-03, placed within 5 mm of the BGA power balls. The SerDes section has separate analog and digital supplies that should be filtered independently to prevent digital switching noise from coupling into the high-speed analog paths. Follow the manufacturer's reference decoupling schematic in the datasheet figure set.
Do not use a low-quality reference clock for the VSC7158XHT-03; jitter exceeding the SAS 2.0 spec (< 50 ps RMS) will cause intermittent link training failures and degraded OOB signalling. Always use a crystal oscillator or clean PCIe-style clock source. Spread-spectrum clocking is supported only at G1 rates, not G2; disable SSC if operating at 3.0 Gbps.
Estimated: SAS 2.0 3.0 Gbps signalling benefits from pre-emphasis and receive equalization, both of which are integrated in the VSC7158XHT-03 PHY. Backplane insertion loss should not exceed the SAS 2.0 spec budget (approximately 6 dB at 1.5 GHz). For long backplane traces (> 20 inch), enable TX pre-emphasis via the device's management interface.
Impormasyon ng Pagsunod sa Kautusan
RoHS3 compliant per verified distributor listing (semiconductors-ic.com). AEC-Q100 is not applicable for storage expander ICs that target enterprise storage rather than automotive applications. Reach compliance assumed for major-vendor semiconductor parts; halogen-free status not explicitly confirmed in verified data and marked unknown.
