The ADK-1585 Demo Board provides a convenient way to evaluate the various unique features of Holt's HI-1585 transceiver. The HI-1585 is the first MIL-STD-1553/1760 transceiver to provide transmitter-induced tail-off compensation. It also also provides optional receiver output pulse extension, which greatly simplifies decoder design and enhances noise performance.
The board RX and nRX receive outputs have an option to stretch the minimum output pulse width to 300ns. This compensates for narrow output pulses at RX and nRX caused by low amplitude bus signals. In addition, transmitter-induced tail-off compensation is demonstrated in two ways:
1) Switches labeled TOC0A, TOC1A and TOC2A are used in combination to provide up to +75mV or -75mV DC tail-off adjustment on Bus A, which compensates for board layout deficiencies that cause consistent tail-off. The TOC switch settings select one of six correction levels.
2) The DIP switch labeled CLKENA on switch package SW3 may be used to control ENCLKA, which, when enabled, allows the CLKA input pin to synchronize the TXA and nTXA inputs for bus A transmissions This mitigates input signal timing differences, helping to compensate for offset.