Table 24: Ready LED Out conditions

Normal command activity

LED status

 

 

Format in progress, each cylinder change

Toggles on/off

 

 

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 25 for the output characteristics of the LED drive signals.

Table 25:

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

 

 

 

 

9.5.2Differential signals

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

Table 26 defines the general interface characteristics.

Table 26: General interface characteristics

Characteristic

Units

1.5 Gbps

3.0 Gbps

 

 

 

 

Bit rate (nominal)

Mbaud

1,500

3,000

 

 

 

 

Unit interval (UI)(nominal)

ps

666.6

333.3

 

 

 

 

Impedance (nominal, differential )

ohm

100

100

 

 

 

 

Transmitter transients, maximum

V

± 1.2

± 1.2

 

 

 

 

Receiver transients, maximum

V

± 1.2

± 1.2

 

 

 

 

9.5.2.1Eye masks

9.5.2.1.1Eye masks overview

The eye masks are graphical representations of the voltage and point. The time values between X1 and (1 - X1) cover all but 10-12of the total jitter population has a range of ± 7 standard deviations.

time limits on the signal at the compliance of the jitter population. The random content

Savvio 10K.2 SAS Product Manual, Rev. B

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Seagate ST9146802SS, ST973402SS manual LED drive signal, Differential signals, General interface characteristics

ST973402SS, ST9146802SS specifications

The Seagate ST973402SS and ST9146802SS are high-performance, enterprise-grade hard drives designed to meet the demanding needs of data-intensive applications. These drives are part of Seagate's Savvio and Barracuda product lines, aimed specifically at businesses and institutions requiring reliability, speed, and efficiency in storage solutions.

The ST973402SS is a 73GB, 2.5-inch hard drive, while the ST9146802SS offers a larger capacity of 146GB. Both models utilize a 10,000 RPM spindle speed, which significantly enhances their ability to handle fast data read and write operations. This speed ensures reduced latency and improved overall performance, making them ideal for environments where rapid access to data is crucial.

One of the standout features of these drives is their support for Serial Attached SCSI (SAS) interface. SAS technology provides a point-to-point connection, which allows for increased data transfer rates compared to traditional SATA drives. The ST973402SS and ST9146802SS are capable of transferring data at speeds of up to 600 MB/s, facilitating efficient data transfers in enterprise systems.

In terms of reliability, both models offer advanced features designed to improve data integrity and durability. They are built to withstand high workloads, with an annualized workload rate of up to 550 TB per year. This makes them well-suited for applications like databases and transactional storage, where sustained performance is required. Additionally, the drives feature Seagate’s PowerFit technology, which optimizes performance while minimizing power consumption.

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Overall, the Seagate ST973402SS and ST9146802SS are robust and reliable hard drives that cater to the needs of enterprise environments, combining high capacity, exceptional speed, advanced security features, and energy efficiency to help businesses maintain and manage large volumes of data effectively. With their proven performance and innovative technologies, these drives are well-equipped to support a wide range of applications in modern data centers.