All versions are Not Recommended for New Designs.
The 78Q2120C09-DB is a design example for a 10/100BASE-TX Mbit/second Fast Ethernet MII Interface adaptor. The 78Q2120C09 transceiver provides the network physical interface and MII (Medium Independent Interface) interface.
Teridian Semiconductor's 78Q2120C09 is an auto-sensing, auto-switching 10/100BASE-TX Fast Ethernet transceiver with full duplex operation capability. The device interfaces directly to the IEEE®-802.3u MII port. Full-featured MII management functions are included along with an extended register set. A five bit configurable PHY address is provided for multiple PHY architectures. The 78Q2120C09 interfaces to CAT5 UTP cable via a 1:1 transformer.
The transceiver's transmitter includes on-chip the pulse shaper and low power line driver. The receiver incorporates a sophisticated combination of real-time adaptive equalization, an adaptive DC offset adjustment circuit and baseline wander correction. Smart squelch circuitry further improves the receiver's noise rejection. Full featured auto-negotiation or parallel detect modes are supported.
Using 0.18µm CMOS technology, the 78Q2120C09 operates at +3.3V. Intelligent power management and power down modes minimize power consumption. The demo board requires operation with a +3.3V power supply.