Seagate ST373355SS, ST3146755SS manual Impedance requirements Sheet 2, Electrical TxRx connections

Page 74

Table 23: Impedance requirements (Sheet 2 of 2)

Requirement

Units

1.5 Gbps

3.0 Gbps

 

 

 

 

Common mode impedanceb,e

ohm

20 min/40 max

20 min/40 max

Transmitter source termination

 

 

 

 

 

 

 

Differential impedanceb

ohm

60 min/115 max

60 min/115 max

Differential impedance imbalanceb,g

ohm

5

5

Common mode impedanceb

ohm

15 min/40 max

15 min/40 max

aAll times indicated for time domain reflectometer measurements are recorded times. Recorded times are twice the transit time of the time domain reflectometer signal.

bAll measurements are made through mated connector pairs.

cThe media impedance measurement identifies the impedance mismatches present in the media when terminated in its characteristic impedance. This measurement excludes mated connectors at both ends of the media, when present, but includes any intermediate connectors or splices. The mated connectors measurement applies only to the mated connector pair at each end, as applicable.

dWhere the media has an electrical length of > 4 ns the procedure detailed in SFF-8410, or an equivalent procedure, shall be used to determine the impedance.

eThe receiver termination impedance specification applies to all receivers in a TxRx connection and covers all time points between the connector nearest the receiver, the receiver, and the transmission line terminator. This measurement shall be made from that connector.

fAt the time point corresponding to the connection of the receiver to the transmission line the input capacitance of the receiver and its connection to the transmission line may cause the measured impedance to fall below the minimum impedances specified in this table. The area of the impedance dip (amplitude as ρ, the reflection coefficient, and duration in time) caused by this capacitance is the receiver termination time constant. The receiver time constant shall not be greater than the values shown in this table. An approximate value for the receiver termination time constant is given by the product of the amplitude of the dip (as ρ) and its width (in ps) measured at the half amplitude point. The amplitude is defined as being the difference in the reflection coefficient between the reflection coefficient at the nominal impedance and the reflection coefficient at the minimum impedance point. The value of the receiver excess input capacitance is given by the following equation:

receiver termination time constant C = -----------------------------------------------------------------------------------------

(R0 RR)

where (R0 RR) is the parallel combination of the transmission line characteristic impedance and termination resistance at the receiver.

gThe difference in measured impedance to ground on the plus and minus terminals on the interconnect, transmitter or receiver, with a differential test signal applied to those terminals.

9.5.2.4Electrical TxRx connections

TxRx connections may be divided into TxRx connection segments. In a single TxRx connection individual TxRx connection segments may be formed from differing media and materials, including traces on printed wir- ing boards and optical fibers. This subclause applies only to TxRx connection segments that are formed from electrically conductive media.

Each electrical TxRx connection segment shall comply with the impedance requirements of table 23 for the media from which they are formed. An equalizer network, if present, shall be part of the TxRx connection.

TxRx connections that are composed entirely of electrically conducting media shall be applied only to homoge- nous ground applications (e.g., between devices within an enclosure or rack, or between enclosures intercon- nected by a common ground return or ground plane).

9.5.2.4.1Transmitter characteristics

The drive is D.C. coupled.

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Cheetah T10 SAS Product Manual, Rev. A

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Contents Cheetah T10 SAS Page Contents Seagate Technology support services Defect and error managementInstallation Interface requirementsList of Figures Cheetah T10 SAS Product Manual, Rev. a Scope Cheetah T10 SAS disc driveCheetah T10 SAS Product Manual, Rev. a Electromagnetic compatibility Standards, compliance and reference documentsStandards Electromagnetic susceptibilityCompliance Reference documents Cheetah T10 SAS Product Manual, Rev. a General description Performance Standard featuresMedia description Formatted capacities Factory-installed accessoriesReliability Programmable drive capacityOptions factory installed User-installed accessoriesAccess time Performance characteristicsInternal drive characteristics Seek timeStart/stop time Format command execution time minutesGeneral performance characteristics Prefetch/multi-segmented cache control Cache operationCaching write data Prefetch operationRecoverable Errors Reliability specificationsError rates Unrecoverable ErrorsInterface errors Reliability and serviceSeek errors Preventive maintenanceControlling S.M.A.R.T Hot plugging the drive4 S.M.A.R.T Performance impactPredictive failures Reporting controlDetermining rate Thermal monitorReference Temperature Temperature Log Page 0DhPrimary Temperature Parameter Code DescriptionShort and extended tests State of the drive prior to testingInvoking DST Short test Function Code 001bShipping Product warrantyAbort Product repair and return informationCheetah T10 SAS Product Manual, Rev. a DC power requirements Physical/electrical specificationsAC power requirements ST3300555SS DC power requirementsST3146755SS Gbit mode Amps ST3146755SS DC power requirementsST373355SS DC power requirements ST373355SS Gbit mode AmpsConducted noise immunity General DC power requirement notesPower sequencing Current profilesTypical ST3300555SS drive current profiles Typical ST3146755SS drive current profiles Typical ST373355SS drive current profiles ST3300555SS in 1.5 Gbit operation Power dissipationST3300555SS in 3 Gbit operation ST3146755SS in 3 Gbit operation ST3146755SS in 1.5 Gbit operationST373355SS in 3 Gbit operation ST373355SS in 1.5 Gbit operationTemperature a. Operating Environmental limitsShock and vibration Relative humidityEffective altitude sea level a. Operating ShockPackage size Packaged/product weight Drop height Recommended mountingCorrosive environment Air cleanlinessVibration a. Operating-normal Mechanical specifications AcousticsDrive error recovery procedures Defect and error managementDrive internal defects/errors Write retry count LBA cumulative, msec Media Pre-Scan SAS system errorsBackground Media Scan Deferred Auto-Reallocation Idle Read After WriteInstallation Drive orientationCooling Air flowDrive mounting GroundingCheetah T10 SAS Product Manual, Rev. a SAS features Interface requirementsDual port support Command name Command code Supported Scsi commands supportedCommands supported by Cheetah T10 SAS family drives Commands supported by Cheetah T10 SAS family drives Commands supported by Cheetah T10 SAS family drives Commands supported by Cheetah T10 SAS family drives Cheetah T10 SAS inquiry data Mode Sense dataInquiry data Bytes Data hexPage ST3300555SS Mode Sense data Mode PagesST3146755SS Mode Sense data ST373355SS Mode Sense data Supported Feature or condition Miscellaneous operating features and conditionsMiscellaneous features Miscellaneous statusSAS physical interface Datum B Physical characteristics Connector requirementsPin descriptions Pin Signal name Signal typeElectrical description SAS pin descriptionsSAS transmitters and receivers Signal characteristicsPower Ready LED OutGeneral interface characteristics LED drive signalDifferential signals Eye masks Eye masks overviewAbsolute amplitude Receive eye maskJitter tolerance masks Normalized time in UIJitter Peak-toSinusoidal Frequency in kHzTransmitter signal characteristics Signal characteristica Units GbpsMaximum allowable jitter Receiver signal characteristicsSignal characteristic Units Gbps Gbps m, n Deterministic jitterqCompliant jitter test pattern Cjtpat Impedance specificationsReceiver jitter tolerance Impedance requirements Sheet 1Electrical TxRx connections Transmitter characteristicsImpedance requirements Sheet 2 = -5,437dB Shows the zero-length test load Receiver characteristics Cheetah T10 SAS Product Manual, Rev. a Internet MySeagate Spp.seagate.com Seagate Technology support servicesWarranty Service Presales SupportData Recovery Services Authorized Service Centers Data Recovery ServicesToll-free support numbers FAX services-All Europe toll callCall center Presales and Technical Support Warranty Service Africa/Middle East support services Index NumericsPage SAS See also cooling Page Seagate Technology LLC

ST3300555SS, ST3146755SS, ST373355SS specifications

The Seagate ST373355SS, ST3146755SS, and ST3300555SS represent a range of high-performance hard drives designed for enterprise applications, particularly in server environments requiring reliability, speed, and high capacity.

The ST373355SS is a 73.5 GB SCSI hard drive operating at 15,000 RPM, which ensures rapid data access and superior performance, making it ideal for transactional applications and data-intensive tasks. With its 4 MB cache, the drive leverages fast read and write speeds, enhancing overall system responsiveness. The SCSI interface, operating at 80 MB/s, allows for high-speed data transfers, making it a suitable choice for demanding environments where quick access to information is critical. Its hot-swappable feature enables maintenance without shutting down the system, maximizing uptime and productivity.

The ST3146755SS, with a capacity of 146.8 GB, builds on the performance of its predecessor while introducing improvements in data handling and reliability. Operating at the same impressive 15,000 RPM, this model also features a 16 MB cache that greatly improves data throughput and access speed. The drive is designed to reduce latency, which is crucial for applications where timing is everything. It is equipped with advanced error recovery features and Seagate’s innovative PowerTrim technology, which improves power efficiency during read and write operations. The ST3146755SS also features a higher mean time between failures (MTBF), underscoring its reliability in high-demand environments.

Lastly, the ST3300555SS offers even greater capacity with 300 GB. This drive maintains the 15,000 RPM rotation speed and benefits from a 16 MB cache, providing a balance of speed and storage capacity. Its advanced SCSI interface supports not just speed but also data integrity, ensuring consistent performance during extensive data transfers. The drive is designed to handle workloads naturally associated with enterprise servers, data warehouses, and video editing applications. Its rugged build supports continuous operation and is tested for high-temperature environments to ensure durability.

In summary, the Seagate ST373355SS, ST3146755SS, and ST3300555SS hard drives are engineered for enterprise environments, combining impressive RPM speeds, significant storage capacities, and advanced technologies to deliver reliability, performance, and efficiency for critical applications. These hard drives represent Seagate's commitment to providing solutions that meet the rigorous demands of modern data environments.
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