Seagate ST3146755SS ユーザーズマニュアル

62

Cheetah T10 SAS Product Manual, Rev. A

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.      

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

Table 18 defines the general interface characteristics.

The eye masks are graphical representations of the voltage and time limits on the signal at the compliance 
point. The time values between X1 and (1 - X1) cover all but 10

-12 

of the jitter population. The random content 

of the total jitter population has a range of 

± 7 standard deviations.

LED off, high

0 V 

≤

 VOH 

≤

 3.6 V

-100 µA < I

OH

 < 100 µA

LED o

n, low

I

OL

 = 15 mA

0 

≤

 V

OL

 

≤

 0.225 V

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