Seagate Barracuda 18XL ST318416N, Product Manual

Page: 91 / 110

Barracuda 18XL Product Manual, Rev. A 81
Note. Resistors are ± 0.1%
Figure 13. LVD steady-state output voltage test circuit (T10/1302D, Annex A, Figure 1)
Input characteristics
Each signal (Vs) received by LVD interface receiver circuits shall have the following input characteristics when
measured at the disk drive connector:
Steady state Low level output voltage* = 0.030 V = < V
s
= < 3.6 V (signal negation/logic 0)
Steady state High level output voltage* = –3.6 V = < V
s
= < –0.030 V (signal assertion/logic 1)
Differential voltage = +0.30 V minimum with common-mode voltage ranges 0.700 V = < V
cm
= < 1.800 V. (T10/
1302D, SPI-3)
*These voltages shall be measured between the output terminal and the SCSI device’s logic ground reference.
Input characteristics shall additionally conform to EIA RS-485-983.
Figure 14. Typical SE-LVD alternative transmitter receiver circuits
V1
–SIGNAL
100
Ω
V2
+SIGNAL
MEASURED
PARAMETER
STEADY STATE
LOGIC INPUT
(1 OR 0)
DEVICE CONNECTOR
100
Ω
75
Ω
Vs
D
VCCA VCCB
Single
Ended
Circuitry Single
Ended
Receiver Single
Ended
Negation
Driver
Single
Ended
Assertion
Driver
Single
Ended
Ground
Driver
Single Ended:
LVD:
LVD Signal Drivers
LVD Signal Drivers
LVD
Receiver
Ground
GND
+Signal
–Signal
–Signal