SSTVF16857AGT - 14-Bit DDR Registered Buffer SSTL_2 | Renesas
N.º da peça: SSTVF16857AGT ✗ Fim de vida| Qtd. | Preço unitário | Total |
|---|---|---|
| 1 | $1 | $1,00 |
| 10 | $0 | $0,00 |
| 100 | $0 | $0,00 |
| 500 | $0 | $0,00 |
| 1.000 | $0 | $0,00 |
SSTVF16857AGT Visão geral
A registered buffer is a specialty logic device that sits between a memory controller and DRAM chips, latching address and command signals on the rising edge of a differential clock before re-driving them to the memory array. Within the system hierarchy, it belongs to the category of logic ICs -> specialty logic -> registered buffers, a class that includes DDR register, PLL-free and PLL-based variants. By regenerating and redistributing heavily loaded control signals, registered buffers reduce capacitive loading on the memory controller, improve signal integrity across long stub-rich DIMM topologies, and enable higher memory clock rates such as DDR PC1600 through PC3200 speeds.
Key features of the SSTVF16857AGT include its 14-bit registered drive width sized precisely for DDR RDIMM address/control bus needs, true SSTL_2 input and output levels compatible with 2.5 V DDR signaling, and differential clock inputs (CK/CK#) that reject common-mode noise on the clock pair. The part is specified for surface-mount assembly in the 48-TFSOP (0.240 inch, 6.10 mm width) package, supporting high-density memory module layouts with standard reflow soldering processes.
Technically, the device registers 14 input channels and re-drives them with SSTL_2-class output drivers matched to DDR DRAM input stages. The latch stage is clocked by a differential pair, allowing precise setup/hold alignment across the register even when clock edges arrive with skew. Tight output skew and matched drive impedance help hold bus timing margin at PC3200-class frequencies where bit time shrinks to under 1 ns.
Typical applications include DDR1 registered DIMM (RDIMM) address/control registration, memory resynchronizer boards, server and workstation memory subsystems, and any legacy DDR memory controller interface requiring buffered, retimed SSTL_2 signals.
Design consideration: verify supply regulation within the 2.3 V to 2.7 V window and provide SSTL_2-appropriate termination on both input and output nets, since SSTL_2 signaling relies on parallel termination to a termination rail for proper switching thresholds and reduced reflections.
This page adds value beyond the manufacturer datasheet by consolidating distributor availability, verified package and supply specifications, and drop-in alternative analysis in one place.
Alternativas drop-in para SSTVF16857AGT — mesmo encapsulamento, compatível pino a pino. Peças de encapsulamento diferente que exigem retrabalho na PCB são excluídas.
Ferramenta de comparação rápida — selecione peças alternativas para comparação lado a lado:
SSTVF16857AG
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SSTVF16857
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SSTVF16857
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SSTVF16857AGT Classificações máximas e características elétricas
| Logic Type | Registered Buffer with SSTL_2 Inputs and Outputs |
| Application | DDR Memory Register (DDR PC1600-PC3200) |
| Bit Width | 14-Bit |
| Tensão de alimentação | 2.3 V to 2.7 V |
| Nominal Supply Voltage | 2.5 V |
| Input Logic Standard | SSTL_2 |
| Output Logic Standard | SSTL_2 |
| Clock Input | Differential clock inputs (CK / CK#) |
| Encapsulamento / Caixa | 48-TFSOP (0.240 in, 6.10 mm width) |
| Package Alias | 48-TSSOP |
| Tipo de montagem | Surface Mount |
| Packaging | Tape & Reel (GT suffix) |
| Categoria | Logic - Specialty Logic |
Guia de Configuração de Pinos do SSTVF16857AGT 48-tssop
Configuração de pinos para SSTVF16857AGT (pacote 48-tssop). Este CI digital inclui GPIO, interfaces de comunicação (UART, SPI, I2C) e pinos de alimentação. Consulte o datasheet do fabricante para funções alternativas dos pinos e opções de configuração. Essencial para projeto de sistemas embarcados e layout de PCB.
Nenhum dado detalhado de pinagem disponível para SSTVF16857AGT.
Consulte a ficha técnica para a configuração completa dos pinos.
Aplicações típicas
SSTVF16857AGT é adequado para 6 aplicaçãos: DDR1 Registered DIMM (RDIMM), Server and Workstation Memory Subsystems, Memory Resynchronizer and Buffer Boards, Legacy DDR Memory Controller Interfaces, Industrial Control Systems with DDR1 Memory, Prototype and Repair of Legacy Memory Boards.
DDR1 Registered DIMM (RDIMM)
The primary application of the SSTVF16857AGT is address and control signal registration on DDR1 registered DIMMs. The device's 14-bit width matches the RDIMM address/control bus partition, its SSTL_2 I/O levels match DDR DRAM input stages at a 2.5 V nominal supply (2.3 V to 2.7 V range), and its differential clock inputs allow retiming of heavily loaded nets. Placed between the edge-connector controller signals and the DRAM address/control pins, it reduces capacitive loading on the controller and re-drives signals with matched SSTL_2 drivers, preserving timing margin at DDR PC1600 through PC3200 data rates across the stub-rich DIMM topology.
Recomendado
Server and Workstation Memory Subsystems
Server and workstation platforms that use DDR1 registered memory rely on register devices such as the SSTVF16857AGT to maintain signal integrity across multi-DIMM channels. The registered buffer decouples the controller from the high fan-out of populated DIMM slots: each register output drives only its local DRAM loads, so the controller sees a single light load per net. With 2.3 V to 2.7 V supply tolerance, the part can share the platform 2.5 V DDR rail. The differential CK/CK# clocking rejects common-mode noise on the clock distribution, supporting reliable operation at PC3200-class frequencies in dense server memory configurations with multiple stacked modules.
Recomendado
Memory Resynchronizer and Buffer Boards
Test, emulation, and protocol-analysis platforms frequently need to isolate or retime DDR1 address/control buses, and the SSTVF16857AGT provides exactly that function: 14 registered SSTL_2 channels clocked by a differential pair. In a resynchronizer board, the input stage accepts SSTL_2 signaling directly from the controller under test, the register stage aligns all 14 signals to a clean local clock edge, and the SSTL_2 output drivers feed analyzer circuitry or a secondary memory array. This preserves DDR setup/hold relationships while giving test equipment a clean, re-driven replica of the bus without adding excessive propagation skew between channels.
Recomendado
Legacy DDR Memory Controller Interfaces
Embedded and networking controllers with legacy DDR1 interfaces use registered buffers like the SSTVF16857AGT when DRAM loading exceeds the controller drive capability. Because the part registers signals rather than merely buffering them combinationally, it can sit a clock cycle into the address/control path, letting the designer manage controller-to-DIMM flight time explicitly. The SSTL_2 standard at 2.5 V matches the DDR1 environment natively, and the 48-TFSOP surface-mount footprint fits standard PCB assembly. Designs must budget the register's propagation delay into memory timing closure, trading one clock of latency for dramatically improved signal integrity on high-fan-out nets.
Recomendado
Industrial Control Systems with DDR1 Memory
Industrial controllers and legacy automation equipment that still use DDR1 SDRAM benefit from registered buffering to survive electrically noisy environments. The SSTVF16857AGT's SSTL_2 differential clock inputs reject common-mode noise injected into clock distribution wiring, while registered re-driving regenerates full-amplitude address/control edges that would otherwise be degraded by long, heavily loaded PCB traces near motors and drives. Operating from a 2.3 V to 2.7 V supply, it tolerates rail sag typical of industrial power supplies. Repair and life-extension of these platforms is a common reason to source this EOL part from remaining distributor stock today.
Recomendado
Prototype and Repair of Legacy Memory Boards
Because the SSTVF16857AGT is end-of-life, its most active current use case is repair, prototyping, and reverse-engineering of DDR1 registered memory boards. Technicians replacing failed registers on RDIMMs or server memory boards need a pin- and function-compatible part; the SSTVF16857AGT in 48-TFSOP with SSTL_2 I/O is the original-fit component in many such assemblies. When sourcing, confirm package suffix compatibility (GT indicates tape and reel) and plating option to match existing assembly processes. Cross-brand drop-in candidates such as the NXP SSTVF16857 should be verified pin-for-pin against the board footprint before substitution.
Recomendado
Resumo dos produtos recomendados
Dados de referência de engenharia para SSTVF16857AGT — comparação, orientação de projeto e informações de conformidade.
Guia de seleção
Comparação com alternativas
| Parâmetro | Este produto | SSTVF16857AG | SSTVF16857 (Renesas) | SSTVF16857 (NXP) |
|---|---|---|---|---|
| Package | 48-TFSOP (0.240 in, 6.10 mm width) | 48-TFSOP (0.240 in, 6.10 mm width) - same | 48-TFSOP (0.240 in, 6.10 mm width) - same | 48-TSSOP - same footprint, verify drawing |
| Brand | Renesas Electronics (IDT) | Renesas Electronics (IDT) | Renesas Electronics (IDT) | NXP Semiconductors (Philips) |
| Logic Function | 14-bit registered buffer, SSTL_2 I/O | 14-bit registered buffer, SSTL_2 I/O | 14-bit registered buffer, SSTL_2 I/O | 14-bit SSTL_2 registered driver, DDR PC1600-PC3200 |
| Clock Input | Differential (CK / CK#) | Differential (CK / CK#) | Differential (CK / CK#) | Differential clock inputs |
| Memory Standard | DDR1 (PC1600-PC3200) | DDR1 (PC1600-PC3200) | DDR1 (PC1600-PC3200) | DDR PC1600-PC3200 |
| Mounting Type | Surface Mount | Surface Mount | Surface Mount | Surface Mount |
| Lifecycle Status | EOL (distributor stock / quote) | EOL (distributor stock / quote) | EOL (distributor stock / quote) | EOL / NRND - verify availability |
Principais diferenciais
- 14-bit width matched exactly to DDR1 address/control partition (vs SSTVF16857 (NXP))
- Differential clock inputs (CK/CK#) for noise rejection (vs SSTVF16857AG (same-family packaging variant))
- DDR PC1600-PC3200 timing grade (vs SSTVF16857 (Renesas base suffix))
Notas de projeto
Supply the SSTVF16857AGT from the same regulated 2.5 V DDR rail (permitted range 2.3 V to 2.7 V) that terminates the SSTL_2 bus, or from a rail derived from it. Track SSTL_2 Class II termination depends on the termination rail voltage; if the register shares that rail, threshold tracking is automatic. Place at least one 0.1 uF ceramic decoupling capacitor at each supply pin and one bulk 10 uF capacitor per device, keeping decoupling loops short. Estimate: SSTL_2 Class II output drive is current-heavy during simultaneous switching of 14 outputs, so budget switching current in the rail design rather than assuming quiescent-only loading.
Route the differential CK/CK# clock pair with controlled impedance and matched length; the register timing of all 14 channels depends on this pair. On the output side, apply SSTL_2 parallel termination (typically to a termination rail) at the DRAM end of each address/control net and keep stubs short to limit reflections at PC3200-class data rates, where bit time is under 1 ns. Verify that register propagation delay plus trace flight time still meets DRAM address setup/hold at the memory controller's clock frequency; on registered DIMM topologies this delay is accounted for by the memory controller's registered-mode timing budget.
Do not use this part in DDR2 or DDR3 designs: SSTL_2 at 2.5 V is incompatible with SSTL_18 (1.8 V) and SSTL_15 (1.5 V) signaling, and exceeding the 2.7 V maximum supply risks damaging the device. Because the part is end-of-life, qualify an alternative (for example the NXP SSTVF16857, verified pin-for-pin) before committing a repair lot, and confirm the exact ordering suffix (GT = tape and reel) so plating and packaging match your assembly process. Note that operating temperature range, quiescent current, and RoHS status were not confirmed in the verified data and must be taken from the official Renesas datasheet.
Informações de conformidade
Compliance data was not present in the verified web data. The original IDT part predates broad RoHS transitions; ordering suffix (e.g., GT tape-and-reel) may indicate plating/packaging option. Obtain material declarations from Renesas or the distributor for the exact suffix.
