HI-25850

The HI-25850 is an ultra-low power CMOS dual transceiver with integrated transformers designed to meet the requirements of the MIL-STD-1553 and MIL-STD-1760 specifications. The dual transceivers with integrated transformers provide a single part solution for interfacing a protocol IC or FPGA to a dual redundant MIL-STD-1553 bus.

The transmitter section of each bus takes complementary CMOS / TTL Manchester II bi-phase data and converts it to differential voltages suitable for driving the integrated isolation transformer. Separate transmitter inhibit control signals are provided for each transmitter. The receiver section of the each bus converts the 1553 bus differential data to complementary CMOS / TTL data suitable for inputting to a Manchester decoder. Each bus has its own Receive Enable input, which forces both receive output signals to the bus idle state (logic "0") when disabled.

The device also features 1.8V, 2.5V and 3.3V compatible digital I/O, making it easier to interface with a broad range of FPGAs.

To reduce end-of-transmission residual voltage offset (”tail-off”), logic-level transmit signal inputs can be clocked-in to synchronize their rise/fall transitions. This compensates for timing mismatch or transmit signal path propagation differences caused by board layout. When sub-optimal board design consistently presents tail-off magnitudes close to or exceeding mandatory limits, another unique option lets the user select a bus-specific level of digital tail-off compensation. 

The HI-25850 also provides optional Receive output pulse extension. With traditional MIL-STD-1553 transceivers, low amplitude receive signals can result in RX/nRX pulses less than 100ns wide. When this feature is enabled, RX/nRX output pulse widths do not drop below 180ns, greatly simplifying decoder design and enhancing noise performance.

The family of parts are available in Industrial -40^oC to +85^oC, or Extended, -55^oC to +125^oC temperature ranges.