The Am79C874 NetPHY-1LP device provides the physical (PHY) layer and transceiver functions for one 10/100 Mbps Ethernet port. It delivers the dual benefits of CMOS low power consumption and small package size. Operating at 3.3 volts, it consumes only 0.3 watts. Three PowerWise™ management modes provide options for even lower power consumption levels. The small 12x12 mm 80-pin TQFP package conserves valuable board space on adapter cards, switch uplinks, and embedded Ethernet applications.

The NetPHY-1LP 10/100 Mbps Ethernet PHY is IEEE 802.3u compliant. It can receive and transmit data reliably at over 130 meters. It includes on-chip input filtering and output wave shaping for unshielded twisted pair operation over Category 5 cables, without requiring external filters or chokes. The NetPHY-1LP device supports 1:1 transmit transformers or 1.25:1 transmit transformers. The 1.25:1 transmit ratio provides 10% lower power consumption. A PECL interface is available for fiber optic 100BASE-FX applications.

Interface to the Media Access Controller (MAC) layer is via the standard Media Independent Interface (MII). A 7-wire interface (GPSI) can be used for 10BASE-T operation. Auto-Negotiation determines the network speed and full or half-duplex operation. Automatic polarity correction is performed during Auto-Negotiation and during 10BASE-T signal reception.

Multiple LED pins are provided for front panel status feedback. One option is to use dual-color LEDs which flash to show if the device is in 100BASE-TX or 10BASE-T mode, half or full duplex, and if data is being received. Individual LEDs can indicate link detection, collision detection, and data transmission.