12.6.2LED driver signals

Fault and Active LED signals are located in the FC-SCA connector (J1). See Table 30 for the output character- istics of the LED drive signals.

Table 30: LED drive signal

State

Current drive available

Output voltage

 

 

 

LED off, high

0 < IOH < 100µA

 

 

 

 

LED on, low

IOL < -30 mA

0 < VOL < 0.8V

 

 

 

12.6.3FC Differential output

The serial output signal voltage characteristics are provided in Table 31. The outputs are not AC coupled in order to deliver maximum signal without rise and fall time degradation. You must AC couple the receiver to iso- late potentially different DC characteristics of the outputs and the receiver.

Table 31:

FC Differential output characteristics

 

 

 

 

Description

Parameter

Notes

 

 

 

Serial output voltage swing

600 < Vout < 1300 mV

Centered at 1.32V

 

 

 

 

Figure 16 provides the data output valid eye diagram relative to the bit cell time.

Vout (mv)

Bit Time

XMIT Eye

Figure 16. Transmit eye diagram

12.6.4FC Differential input

The serial input signal voltage characteristics are provided in Table 32.

Table 32:

FC Differential input characteristics

 

 

 

 

Description

Parameter

Notes

 

 

 

Serial input voltage swing

200 < Vin < 1.300 mV

AC coupled

 

 

 

 

Cheetah 15K.7 FC Product Manual, Rev. C

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Image 79
Seagate ST3600957FC, ST3300557FC, ST3300457FC, ST3300657FC LED driver signals, FC Differential output, FC Differential input