EP4CE30F29C7N Datasheet, PDF (121/488 Pages) Altera Corporation – Cyclone IV Device Handbook, Volume 1

Chapter 6: I/O Features in Cyclone IV Devices
Termination Scheme for I/O Standards
6–15
Differential I/O Standard Termination
Differential I/O standards typically require a termination resistor between the two
signals at the receiver. The termination resistor must match the differential load
impedance of the bus (refer to Figure 6–7 and Figure 6–8).
Cyclone IV devices support differential SSTL-2 and SSTL-18, differential HSTL-18,
HSTL-15, and HSTL-12, PPDS, LVDS, RSDS, mini-LVDS, and differential LVPECL.
Figure 6–7. Cyclone IV Devices Differential HSTL I/O Standard Class I and Class II Interface and Termination
Termination
Differential HSTL Class I
External
On-Board
Termination
VTT VTT
50 Ω
50 Ω
50 Ω
50 Ω
OCT
Transmitter
Cyclone IV Device
Family Series OCT
50 Ω
VTT VTT
50 Ω 50 Ω
50 Ω
Receiver
Transmitter
50 Ω
Receiver
Differential HSTL Class II
VTT VTT
VTT VTT
50 Ω
50 Ω 50 Ω
50 Ω
50 Ω
50 Ω
Transmitter
Receiver
VTT VTT
VTT VTT
Cyclone IV Device
Family Series OCT
25 Ω
50 Ω 50 Ω 50Ω 50 Ω
50 Ω
Transmitter
50 Ω
Receiver
Figure 6–8. Cyclone IV Devices Differential SSTL I/O Standard Class I and Class II Interface and Termination ⁽¹⁾
Termination
Differential SSTL Class I
External
On-Board
Termination
VTT VTT
50 Ω
25 Ω
50 Ω
50 Ω
25 Ω
50Ω
Transmitter
OCT
Cyclone IV Device
Family Series OCT
50 Ω
Receiver
VTT VTT
50 Ω 50 Ω
50 Ω
Transmitter
50 Ω
Receiver
Note to Figure 6–8:
(1) Only Differential SSTL-2 I/O standard supports Class II output.
Differential SSTL Class II
VTT VTT
VTT VTT
50 Ω
25 Ω
50 Ω 50 Ω
50 Ω
50 Ω
25 Ω
50 Ω
Transmitter
Receiver
VTT VTT
VTT VTT
Cyclone IV Device
Family Series OCT
25 Ω
50 Ω 50 Ω 50Ω 50 Ω
50 Ω
Transmitter
50 Ω
Receiver
May 2013 Altera Corporation
Cyclone IV Device Handbook,
Volume 1