Input considerations
The time synchronization input interfaces of the NT SmartNICs are supplied with limited protection.
The time synchronization inputs on the NT SmartNICs do not fully support NT-PPS time synchronization output signals.
Warning: Connecting incompatible signal sources to NT time synchronization input
interfaces might damage the NT SmartNIC hardware.
When a time synchronization input is configured for PPS signals, the rising edge is interpreted as on time.
The Tyco Industrial Mini connectors
The Tyco Industrial Mini connectors on the NT SmartNICs consist of both an SMA port and an
RJ45 port. The connectors must be connected to one of the time synchronization adapters
described in PTP-SMA time synchronization adapter and PTP-RJ45/SMA time synchronization adapter. For the SMA interfaces the
specifications in Specification for MCX- and SMA-based inputs are valid. The
RJ45 interfaces are normal Ethernet data ports.
Note: This connector does not
apply to NT200A02 and NT200A01 SmartNICs.
Specification for MCX- and SMA-based inputs
This table specifies the time synchronization input interface for the MCX- and SMA-based inputs on the NT SmartNICs (the internal and external inputs, respectively).
| Mode | Type | Parameter | Value |
|---|---|---|---|
| Power off/ Interface off | – | Termination | 100 kΩ DC |
| Current in clamping circuit | 60 mA @ 5 V input Note: This only applies to external SMA-based inputs and not
to internal MCX-based inputs.
|
||
| PPS mode | In | Termination | 50 Ω DC |
| Rise/fall time | 0 – 30 ns | ||
| Input levels | Rising edge, TTL levels | ||
| Pulse width | 1 µs – 999 ms | ||
| Current in clamping circuit | 130 mA @ 5 V input | ||
| Out | Rise/fall | 0 – 10 ns | |
| Output levels | Rising edge, TTL levels @ 50 Ω load | ||
| Pulse width | 67 ms | ||
| NTTS mode | In | Termination | 50 Ω AC |
| Rise/fall time | 0 – 30 ns | ||
| Input levels | LVCMOS 2.5 V levels | ||
| Pulse width | Proprietary NT protocol | ||
| Current in clamping circuit | 130 mA @ 5 V input | ||
| Out | Rise/fall | 0 – 10 ns | |
| Output levels | LVCMOS 2.5 V levels | ||
| Pulse width | Proprietary NT protocol |