The HI-1590 is a low power CMOS dual +3.3V transceiver with the ability to vary the amplitude of the transmitter outputs. It is designed to meet the requirements of the MIL-STD-1553 / 1760 specifications, and is pin compatible with the +5.0V HI-1570. The HI-1590 adds SPI communication to an onboard DAC to vary the amplitude of the transmitter outputs.
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 bus isolation transformer. Separate transmitter inhibit control signals are provided for each transmitter. The user has the option to either supply an external voltage to a single analog input pin, or program an 8-bit DAC through a SPI port to control the transmitter output amplitude.
The receiver section of each bus converts the 1553 bus bi-phase differential data to complementary CMOS / TTL data suitable for inputting to a Manchester decoder. Each receiver has a separate enable input which can be used to force the output of the receiver to a logic '0'.