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Seagate ST3500414SS SAS-2 Specification Compliance, Additional information, LED drive signal

Models: ST3500414SS ST3500415SS ST32000445SS ST31000425SS ST32000446SS ST32000444SS ST31000426SS ST3500416SS ST31000424SS

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The Ready LED Out signal is designed to pull down the cathode of an LED. The anode is attached to the proper +3.3 volt supply through an appropriate current limiting resistor. The LED and the current limiting resis- tor are external to the drive. See Table 17 for the output characteristics of the LED drive signals.

Table 17:

LED drive signal

 

 

 

 

 

State

 

Test condition

Output voltage

 

 

 

 

LED off, high

 

0 V ≤VOH ≤3.6 V

-100 µA < IOH < 100 µA

LED on, low

 

IOL = 15 mA

0 ≤VOL ≤0.225 V

12.5.2Differential signals

The drive SAS differential signals comply with the intra-enclosure (internal connector) requirements of the SAS standard.

Table 18 defines the general interface characteristics.

Table 18: General interface characteristics

Characteristic

Units

1.5Gb/s

3.0Gb/s

6.0Gb/s

 

 

 

 

 

Bit rate (nominal)

Mbaud

1,500

3,000

6,000

 

 

 

 

 

Unit interval (UI)(nominal)

ps

666.6

333.3

166.6

 

 

 

 

 

Impedance (nominal, differential )

ohm

100

100

100

 

 

 

 

 

Transmitter transients, maximum

V

± 1.2

± 1.2

± 1.2

 

 

 

 

 

Receiver transients, maximum

V

± 1.2

± 1.2

± 1.2

 

 

 

 

 

12.6SAS-2 Specification Compliance

Seagate SAS-2 drives are entirely compatible with the latest SAS-2 Specification (T10/1760-D) Revision 16.

The most important characteristic of the SAS-2 drive at 6Gb/s is that the receiver is capable of adapting the equalizer to optimize the receive margins. The SAS-2 drive has two types of equalizers:

1.A Decision Feedback Equalizer (DFE) which utilizes the standard SAS-2 training pattern transmitted dur- ing the SNW-3 training gap. The DFE circuit can derive an optimal equalization characteristic to compen- sate for many of the receive losses in the system.

2.A Feed Forward Equalizer (FFE) optimized to provide balanced receive margins over a range of channels bounded by the best and worst case channels as defined by the relevant ANSI standard.

12.7Additional information

Please contact your Seagate representative for SAS electrical details, if required.

For more information about the Phy, Link, Transport, and Applications layers of the SAS interface, refer to the Seagate SAS Interface Manual, part number 100293071.

For more information about the SCSI commands used by Seagate SAS drives, refer to the Seagate SCSI Commands Reference Manual, part number 100293068.

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Constellation ES Series SAS Product Manual, Rev. E

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Seagate ST3500414SS manual SAS-2 Specification Compliance, Additional information, LED drive signal, Differential signals
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ST3500414SS, ST3500415SS, ST32000445SS, ST31000425SS, ST32000446SS specifications

Seagate, a leader in data storage solutions, has introduced a range of high-capacity and reliable hard drives designed for enterprise environments, including the Seagate ST31000424SS, ST3500416SS, ST31000426SS, ST32000444SS, and ST32000446SS. Each of these models is built with an emphasis on performance, endurance, and advanced data protection technologies, catering to mission-critical applications and data-intensive workloads.

The ST31000424SS is a 1TB drive designed for servers and data centers. It offers a 7,200 RPM spindle speed and a 6 Gb/s SATA interface, ensuring quick data access and transfer rates. With a 64MB cache buffer, the ST31000424SS provides enhanced read/write performance, making it suitable for applications that demand quick responses from the storage subsystem.

Similarly, the ST3500416SS is a high-capacity 500GB model, also spinning at 7,200 RPM with a 6 Gb/s SATA interface. This drive is ideal for mid-range servers and enterprise storage, providing an excellent balance of performance and capacity for users looking to optimize their storage efficiency while maintaining lower power consumption.

The ST31000426SS expands the capacity to 1TB while retaining the same reliability and performance characteristics as its counterparts. Its robust design ensures reliability in multi-drive environments, making it an appealing choice for virtualization and database applications, where performance is critical.

The ST32000444SS and ST32000446SS represent Seagate's commitment to higher capacities, with both offering 2TB of storage. They both feature 7,200 RPM speeds, 6 Gb/s SATA interfaces, and 64MB cache buffers, catering to high-demand environments such as cloud storage and data analytics. The drives also integrate advanced error recovery and data integrity features, ensuring the protection of sensitive data, which is vital for enterprise users.

Each model supports Seagate's PowerChoice technology, which optimizes power consumption without sacrificing performance, enhancing energy efficiency in modern data centers. With a broad range of capacities and performance levels, these Seagate drives provide scalable solutions tailored to meet the robust demands of today’s enterprise applications, ensuring reliability and performance for critical data operations.