GTH Transceiver DC Input and Output Levels

Artix UltraScale+ FPGA Data Sheet: DC and AC Switching Characteristics (DS931)

Document ID
DS931
Release Date
2022-04-13
Revision
1.2 English

The following table summarizes the DC specifications of the GTH transceivers in Artix UltraScale+ FPGAs. Consult the UltraScale Architecture GTH Transceivers User Guide (UG576) for further details.

Table 1. GTH Transceiver DC Specifications
Symbol DC Parameter Conditions Min Typ Max Units
DVPPIN Differential peak-to-peak input voltage (external AC coupled) >10.3125 Gb/s 150 1250 mV
6.6 Gb/s to 10.3125 Gb/s 150 1250 mV
≤ 6.6 Gb/s 150 2000 mV
VIN Single-ended input voltage. Voltage measured at the pin referenced to GND DC coupled VMGTAVTT = 1.2V –400 VMGTAVTT mV
VCMIN Common mode input voltage DC coupled VMGTAVTT = 1.2V 2/3 VMGTAVTT mV
DVPPOUT Differential peak-to-peak output voltage 1 Transmitter output swing is set to 11111 800 mV
VCMOUTDC Common mode output voltage: DC coupled (equation based) When remote RX is terminated to GND VMGTAVTT/2 – DVPPOUT/4 mV
When remote RX termination is floating VMGTAVTT – DVPPOUT/2 mV
When remote RX is terminated to VRX_TERM 2 mV
VCMOUTAC Common mode output voltage: AC coupled (equation based) VMGTAVTT – DVPPOUT/2 mV
RIN Differential input resistance 100 Ω
ROUT Differential output resistance 100 Ω
TOSKEW Transmitter output pair (TXP and TXN) intra-pair skew (all packages) 10 ps
CEXT Recommended external AC coupling capacitor 3 100 nF
  1. The output swing and pre-emphasis levels are programmable using the attributes discussed in the UltraScale Architecture GTH Transceivers User Guide (UG576), and can result in values lower than reported in this table.
  2. VRX_TERM is the remote RX termination voltage.
  3. Other values can be used as appropriate to conform to specific protocols and standards.
Figure 1. Single-Ended Peak-to-Peak Voltage

Figure 2. Differential Peak-to-Peak Voltage

Table 2 and Table 3 summarize the DC specifications of the GTH transceivers input and output clocks in Artix UltraScale+ FPGAs. Consult the UltraScale Architecture GTH Transceivers User Guide (UG576) for further details.

Table 2. GTH Transceiver Clock Input Level Specification
Symbol DC Parameter Min Typ Max Units
VIDIFF Differential peak-to-peak input voltage 250 2000 mV
RIN Differential input resistance 100 Ω
CEXT Required external AC coupling capacitor 10 nF
Table 3. GTH Transceiver Clock Output Level Specification
Symbol Description Conditions Min Typ Max Units
VOL Output Low voltage for P and N RT = 100Ω across P and N signals 100 330 mV
VOH Output High voltage for P and N RT = 100Ω across P and N signals 500 700 mV
VDDOUT Differential output voltage (P–N),

P  =  High (N–P), N = High

RT = 100Ω across P and N signals 300 430 mV
VCMOUT Common mode voltage RT = 100Ω across P and N signals 300 500 mV