General Description
Operating at 2.5 volts to meet low voltage and low power requirements, the KS8721B/BT is a 10BaseT/100BaseTX/FX Physical Layer Transceiver, which provides an MII to transmit and receive data. It contains the 10BaseT Physical Medium Attachment (PMA), Physical Medium Dependent (PMD), and Physical Coding Sub-layer (PCS) functions. Moreover, the KS8721B/BT has on-chip 10BaseT output fi ltering, which eliminates the need for external fi lters and allows a single set of line magnetics to be used to meet requirements for both 100BaseTX and 10BaseT.

Features
• Single chip 100BaseTX/100BaseFX/10BaseT physical layer solution
• 2.5V CMOS design, power consumption <200mW (excluding output driver current )
• Fully compliant to IEEE 802.3u standard
• Supports Media Independent Interface (MII) and Reduced MII (RMII)
• Supports 10BaseT, 100BaseTX and 100BaseFX with Far_End_Fault Detection
• Supports power down mode and power saving mode
• Confi gurable through MII serial management ports or via external control pins
• Supports auto-negotiation and manual selection for 10/100Mbps speed and full/half-duplex mode
• On-chip built-in analog front end fi ltering for both 100BaseTX and 10BaseT
• LED outputs for link, activity, full/half duplex, collision and speed
• Supports back to back, FX to TX for media converter applications
• Supports MDI/MDI-X auto crossover
• 2.5V/3.3V tolerance on I/O
• Commercial temperature range: 0°C to +70°C
• Industrial temperature range: –40°C to +85°C
• Available in 48-pin SSOP and TQFP