DS1776  Product Folder

The DS1776 is an octal PI-bus Transceiver. The A to B path is latched. B outputs are open collector with series Schottky diode, ensuring minimum B output loading. B outputs also have ramped rise and fall times (2.5 ns typical), ensuring minimum PI-bus ringing. B inputs have glitch rejection circuitry, 4 ns typical.

Designed using National's Bi-CMOS process for both low operating and disabled power. AC performance is optimized for the PI-Bus inter-operability requirements.

The DS1776 is an octal latched transceiver and is intended to provide the electrical interface to a high performance wired-or bus. This bus has a loaded characteristic impedance range of 20 Ohm to 50 Ohm and is terminated on each end with a 30 Ohm to 40 Ohm resistor.

The DS1776 is an octal bidirectional transceiver with open collector B and TRI-STATE™ A port output drivers. A latch function is provided for the A port signals. The B port output driver is designed to sink 100 mA from 2V and features a controlled linear ramp to minimize crosstalk and ringing on the bus.

A separate high level control voltage (V_X) is provided to prevent the A side output high level from exceeding future high density processor supply voltage levels. For 5V systems, V_X is tied to V_CC.

• Mil-Std-883C qualified
• Similar to BTL
• Low power I_CCL = 41 mA max
• B output controlled ramp rate
• B input noise immunity, typically 4 ns
• Available in 28-pin DIP, Flatpak and CLCC
• Pin and function compatible with Signetics 54F776