The TSB81BA3 provides the digital and analog transceiver functions needed to implement a three-port node in a cable-based IEEE 1394 network. Each cable port incorporates two differential line transceivers. The transceivers include circuitry to monitor the line conditions as needed for determining connection status, for initialization and arbitration, and for packet reception and transmission. The TSB81BA3 is designed to interface with a link-layer controller (LLC), such as the TSB82AA2, TSB12LV21, TSB12LV26, TSB12LV32, TSB42AA4, TSB42AB4, TSB12LV01B, or TSB12LV01C. It may also be connected cable port to cable port to an integrated 1394 Link + PHY layer such as the TSB43AB2.

The TSB81BA3 is powered by dual supplies, a 3.3-V supply for I/O and a core voltage supply. The core voltage supply is supplied to the PLLVDD-CORE and DVDD-CORE terminals to the requirements in the recommended operating conditions. The PLLVDD-CORE terminals must be separated from the DVDD-CORE terminals, the PLLVDD-CORE terminals are decoupled with 1 µF and smaller decoupling capacitors, and the DVDD-CORE terminals separately decoupled with a 1 µF and smaller decoupling capacitors. The separation between DVDD-CORE and PLLVDD-CORE may be implemented by separate power supply rails, or by a single power supply rail, where the DVDD-CORE and PLLVDD-CORE are separated by a filter network to keep noise from the PLLVDD-CORE supply.

The TSB81BA3 requires an external 98.304-MHz crystal oscillator to generate a reference clock. The external clock drives an internal phase-locked loop (PLL), which generates the required reference signal. This reference signal provides the clock signals that control transmission of the outbound encoded information. A 49.152-MHz clock signal is supplied to the associated LLC for synchronization of the two devices and is used for resynchronization of the received data when operating the PHY-link interface in compliance with the IEEE 1394a-2000 standard. A 98.304-MHz clock signal is supplied to the associated LLC for synchronization of the two devices when operating the PHY-link interface in compliance with the IEEE P1394b standard. The power down (PD) function, when enabled by asserting the PD terminal high, stops operation of the PLL.Read more