74ETL16245 Datasheet | National

Description The 54 74ETL16245 contains sixteen non-inverting bidirectional buffers with TRI-STATE outputs designed with incident wave switching live insertion support and enhanced noise margin for TTL backplane applications Both the A and B ports include a bus hold circuit to latch the output to the value last forced on that pin The B port of this device includes 25X series output resistors which minimize undershoot and ringing Features Y Supports the VME64 ETL specification Y Functionally and pin patible with industry standard TTL 16245 SSOP pinout Y Improved TTL-patible input threshold range Y High drive TTL-patible outputs (IOH e b60 m A IOL e 90 m A) Y Supports 25X incident wave switching on the A port Y Bi CMOS design significantly reduces power dissipation Y Distributed VCC and GND pin configuration minimizes high-speed switching noise Y 25X series-dampening resistor on B-port Y Available in 48-pin SSOP and ceramic flatpak Y Guaranteed output skew Y Guaranteed simultaneous switching noise level and dynamic threshold performance Y Guaranteed latchup protection Logic Symbol Connection Diagram Pin Assignment for SSOP and Flatpak TL F 11654 - 1 Pin Description Pin Names DIR OE An Bn Description Transmit Receive Input Output Enable Input (Active LOW) Backplane Bus Data Local Bus Data TRI-STATE is a registered trademark of National Semiconductor Corporation C1995 National Semiconductor Corporation TL F 11654 TL F 11654 - 2 RRD-B30M105 Printed in U S A Functional Description The device uses byte-wide Direction (DIR) control and Output Enable (OE) controls The DIR inputs determine the direction of data flow through the device The OE inputs disable the A and the B ports The part contains active circuitry which keeps all outputs disabled when VCC is less than 2 2V to aid in live insertion applications Logic Diagrams (Positive Logic) Truth Table (Each 8-bit Section) Inputs OE DIR LL LH HX Operation A Data to B Bus B Data to A Bus Isolation TL F 11654-...