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 19 for the output characteristics of the LED drive signals.

Table 19:

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 20 defines the general interface characteristics

Table 20: 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.

72

Savvio 10K.5 SAS Product Manual, Rev. D

Page 80
Image 80
Seagate ST9450205SS manual SAS-2 Specification compliance, Additional information, LED drive signal, Differential signals

ST9600005SS, ST9600205SS, ST9300505SS, ST9300605SS, ST9300405SS specifications

Seagate has long been a prominent player in the storage solutions market, offering a range of hard drives that cater to various needs and applications. Among its extensive lineup, the Seagate ST9600105SS, ST9450405SS, ST9450305SS, ST9900605SS, and ST9900805SS stand out due to their unique features and robust performance, making them suitable for both personal and professional use.

The Seagate ST9600105SS is a 2.5-inch 600GB SAS hard drive that delivers exceptional reliability and performance. With a rotational speed of 10,000 RPM, this drive ensures quick data access through its enhanced data transfer rate. It utilizes a SAS 6Gb/s interface, allowing for fast and efficient data management in enterprise environments. The drive is designed with Seagate's AgileArray technology, which optimizes drive reliability for multi-drive environments, ensuring that users benefit from reduced downtime.

Similarly, the ST9450405SS and ST9450305SS are also 2.5-inch SAS drives, offering capacities of 450GB and 300GB, respectively. Both models feature a 10,000 RPM speed and a 6Gb/s SAS interface, making them ideal for use in data centers and business-critical applications. The ST9450405SS has enhanced power efficiency, aiding in lowering operational costs for enterprises. Both drives incorporate Seagate's advanced error recovery controls, which help maintain data integrity under varying workloads.

On the larger capacity side, the Seagate ST9900605SS and ST9900805SS drives provide even more storage options. Offering 600GB and 800GB capacities, respectively, these drives are designed for high-performance computing environments. They also spin at 10,000 RPM and support the 6Gb/s SAS interface. The ST9900805SS, in particular, is noted for its advanced performance in transactional workloads, making it suitable for database storage, virtualization, and analytics.

All five models feature Seagate’s innovative technologies, including firmware enhancements for improved error correction and reliability. They are also built to operate in a variety of environments, offering robust vibration tolerance.

In summary, the Seagate ST9600105SS, ST9450405SS, ST9450305SS, ST9900605SS, and ST9900805SS represent some of the best storage solutions for high-demand applications. With their emphasis on performance, reliability, and energy efficiency, these drives are engineered to meet the challenges of modern data storage needs, ensuring organizations can rely on them for their critical operations.