Figure 21. Lvd Output Signals; Figure 22. Typical Se-Lvd Alternative Transmitter Receiver Circuits - Seagate ST336706LW Product Manual

66
Output characteristics
Each signal (V ) driven by LVD interface drivers shall have the following output characteristics when measured
s
at the disc drive connector:
Steady state Low level output voltage* = –.95 V = < V
Steady state High level output voltage* = –.95 V = < V
Differential voltage = +0.6 V minimum with common-mode voltage ranges 0.700 V = < V
*These voltages shall be measured between the output terminal and the SCSI device's logic ground reference.
The output characteristics shall additionally conform to EIA RS-485.
STEADY STATE
LOGIC INPUT
(1 OR 0)
Figure 21. LVD output signals
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
Steady state High level output voltage* = –3.6 V = < V
Differential voltage = +0.30 V minimum with common-mode voltage ranges 0.700 V = < V
(X3T10/1302D)
*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 22. Typical SE-LVD alternative transmitter receiver circuits
D
VCCA
LVD Signal Drivers
Single
Ended
Circuitry
Receiver
Single
Ended
Ground
Driver
LVD Signal Drivers
Ground
Single Ended: GND
LVD: +Signal
Cheetah 36ES Product Manual, Rev. A
= < –1.55 V (signal negation/logic 0)
s
= < 1.55 V (signal assertion/logic 1)
s
100
–SIGNAL
V s
75
100
+SIGNAL
MEASURED
PARAMETER
DEVICE CONNECTOR
= < 3.6 V (signal negation/logic 0)
s
= < –0.030 V (signal assertion/logic 1)
s
VCCB
Single
Ended
Receiver
LVD
–Signal
–Signal
= < 1.800 V.
cm
V1
V2
= < 1.800 V.
cm
Single
Ended
Negation
Driver
Single
Ended
Assertion
Driver