Micrel has introduced a range of 4/5-port Ethernet Layer-2 switch-on-a-chip ICs, which the supplier claims achieves a 50% reduction in power consumption compared to its previous devices. 

Energy efficiency has become increasingly important with the application of Ethernet in consumer and industrial networking.

The devices support a single 3.3V power supply with an internal 1.2V LDO, with options for 3.3V, 2.5V or 1.8V IO voltages. 

Power management includes an “Energy Detect Power Down” mode which is activated when the cable is unplugged, and the “slow oscillator” mode is activated when the device is not in use.

The chip interfaces to a host processor and PHY circuits via MII or RMII. 

The ICs generate the 50MHz RMII clock.