SN74SSQEB32882
- 1-to-2 Register Outputs and 1-to-4 Clock Pair
Outputs Support Stacked DDR3 RDIMMs - CKE Powerdown Mode for Optimized System Power Consumption
- 1.5V/1.35V/1.25V Phase Lock Loop Clock Driver for Buffering
One Differential Clock Pair (CK and CK) and Distributing to Four
Differential Outputs - 1.5V/1.35V/1.25V CMOS Inputs
- Checks Parity on Command and Address (CS-Gated) Data Inputs
- Configurable Driver Strength
- Uses Internal Feedback Loop
- APPLICATIONS
- DDR3 Registered DIMMs up to DDR3-1866
- DDR3L Registered DIMMs up to DDR3L-1600
- DDR3U Registered DIMMs up to DDR3U-1333
- Single-, Dual- and Quad-Rank RDIMM
This JEDEC SSTE32882 28-bit 1:2 or 26-bit 1:2 and 4-bit 1:1 registering clock driver with parity is designed for operation on DDR3 registered DIMMs with VDD of 1.5 V, on DDR3L registered DIMMs with VDD of 1.35 V and on DDR3U registered DIMMs with VDD of 1.25 V.
All inputs are 1.5 V, 1.35V and 1.25 V CMOS compatible. All outputs are CMOS drivers optimized to drive DRAM signals on terminated traces in DDR3 RDIMM applications. The clock outputs Yn and Yn and control net outputs DxCKEn, DxCSn and DxODTn can be driven with a different strength and skew to optimize signal integrity, compensate for different loading and equalize signal travel speed.
The SN74SSQEB32882 has two basic modes of operation associated with the Quad Chip Select Enable (QCSEN) input. When the QCSEN input pin is open (or pulled high), the component has two chip select inputs, DCS0 and DCS1, and two copies of each chip select output, QACS0, QACS1, QBCS0 and QBCS1. This is the “QuadCS disabled” mode. When the QCSEN input pin is pulled low, the component has four chip select inputs DCS[3:0], and four chip select outputs, QCS[3:0]. This is the “QuadCS enabled” mode. Through the remainder of this specification, DCS[n:0] will indicate all of the chip select inputs, where n=1 for QuadCS disabled, and n=3 for QuadCS enabled. QxCS[n:0] will indicate all of the chip select outputs.
The device also supports a mode where a single device can be mounted on the back side of a DIMM. If MIRROR=HIGH, Input Bus Termination (IBT) has to stay enabled for all input signals in this case.
The SN74SSQEB32882 operates from a differential clock (CK and CK). Data are registered at the crossing of CK going HIGH, and CK going LOW. This data could be either re-driven to the outputs or it could be used to access device internal control registers.
The input bus data integrity is protected by a parity function. All address and command input signals are added up and the last bit of the sum is compared to the parity signal delivered by the system at the input PAR_IN one clock cycle later. If they do not match the device pulls the open drain output ERROUT LOW. The control signals (DCKE0, DCKE1, DODT0, DODT1, DCS[n:0]) are not part of this computation.
The SN74SSQEB32882 implements different power saving mechanisms to reduce thermal power dissipation and to support system power down states. By disabling unused outputs the power consumption is further reduced.
The package is optimized to support high density DIMMs. By aligning input and output positions towards DIMM finger signal ordering and SDRAM ballout the device de-scrambles the DIMM traces allowing low cross talk design with low interconnect latency.
Edge controlled outputs reduce ringing and improve signal eye opening at the SDRAM inputs.
技術資料
| 種類 | タイトル | 最新の英語版をダウンロード | 日付 | |||
|---|---|---|---|---|---|---|
| * | データシート | SN74SSQEB32882 データシート | 2010年 6月 15日 | |||
| アプリケーション・ノート | Recommendation for Register-Related SPD Settings on DDR3 RDIMM (Rev. B) | 2013年 7月 26日 |
設計および開発
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| パッケージ | ピン数 | CAD シンボル、フットプリント、および 3D モデル |
|---|---|---|
| NFBGA (ZAL) | 176 | Ultra Librarian |
購入と品質
- RoHS
- REACH
- デバイスのマーキング
- リード端子の仕上げ / ボールの原材料
- MSL 定格 / ピーク リフロー
- MTBF/FIT 推定値
- 使用原材料
- 認定試験結果
- 継続的な信頼性モニタ試験結果
- ファブの拠点
- 組み立てを実施した拠点