December 31, 2021
Direct attach copper cable, short for DAC cable, is a kind of fixed high speed copper cable assembly widely used in data switching&control room.
DAC cable is comprised of shielded twinax copper cable with hot plug-and-play connectors on each end with different gauges from 24 to 30AWG, the longer the distance, the higher the AWG is.
Olycom offers 10G/25G SFP28/40G QSFP+/100G Q4SFP28 full range direct attach copper cable.
Generally, it can be classified into two types: passive and active DAC cable.
Passive DAC cables have no electrical components built into the cable assembly. Therefor, it entails the minimal power consumption of no more than 0.15w and generally for short reach ranging from 1m/3m/5m/7m.
3 General Product Features
| Pin | Logic | Symbol | Description |
| 1 | VeeT | Module Transmitter Ground | |
| 2 | LVTTL-O | Tx_Fault | Module Transmitter Fault |
| 3 | LVTTL-I | Tx_Disable | Transmitter disable; Turns off transmitter laser output |
| 4 | LVTTL-I/O | SDA | 2-wire Serial Interface Data Line (Same as MOD-DEF2in INF-8074i) |
| 5 | LVTTL-I/O | SCL | 2-wire Serial Interface Clock(Same as MOD-DEF1 inINF-8074i) |
| 6 | Mod_ABS | Module Absent, connected to VeeT or VeeR in the module | |
| 7 | LVTTL-I | RS0 | Rate Select 0, optionally controls SFP+ module receiver |
| 8 | LVTTL-O | Rx_LOS | Receiver Loss of Signal Indication (In FC designated as Rx_LOS and in Ethernet designated as Signal Detect) |
| 9 | LVTTL-I | RS1 | Rate Select 1,optionally controls SFP+ module transmitter |
| 10 | VeeR | Module Receiver Ground | |
| 11 | VeeR | Module Receiver Ground | |
| 12 | CML-O | RD- | Receiver Inverted Data Output |
| 13 | CML-O | RD+ | Receiver Non-Inverted Data Output |
| 14 | VeeR | Module Receiver Ground | |
| 15 | VccR | Module Receiver 3.3 V Supply | |
| 16 | VccT | Module Transmitter 3.3 V Supply | |
| 17 | VeeT | Module Transmitter Ground | |
| 18 | CML-I | TD+ | Transmitter Non-Inverted Data Input |
| 19 | CML-I | TD- | Transmitter Inverted Data Input |
| 20 | VeeT | Module Transmitter Ground |
| SFP+ DAC Specifications | |
| Number of Lanes | Tx & Rx |
| Channel Data Rate | 10.3125 Gbps |
| Operating Temperature | 0 to + 70°C |
| Storage Temperature | -40 to +85°C |
| Supply Voltage | 3.3 V nominal |
| Electrical Interface | 20pins edge connector |
| Management Interface | Serial, I2C |
4 Conclusion
DAC cable is an ideal high-speed solution for data center interconnections. And all the DAC cables mentioned above are supplied in Olycom.
Please check below links for more product details and contact us for more information.
