The CD74ACT646EN 3-state, octal-bus transceiver/registers use the RCA ADVANCED CMOS technology. They have non-inverting outputs. These devices are bus transceivers with D-type flip-flops which act as internal storage registers on the LOW-to-HIGH transition of either CAB or CBA clock inputs. Output Enable (OE\) and Direction (DIR) inputs control the transceiver functions. Data present at the high-impedance output can be stored in either register or both but only one of the two buses can be enabled as outputs at any one time. The Select controls (SAB and SBA) can multiplex stored and transparent (real time) data. The Direction control determines which data bus will receive data when the Output Enable (OE\) is LOW. In the high-impednace mode (Output Enable HIGH), A data can be stored in one register and B data can be stored in the other register. The clocks are not gated with the Direction (DIR) and Output Enable (OE\) terminals; data at the A or B terminals can be clocked into the storage flip-flops at any time.
Typical propagation delay: 5.3 ns @ VCC = 5 V, TA = 25°C, CL = 50pF
SCR-Latchup-resistant CMOS process and circuit design
Speed of bipolar FAST*/AS/S with significantly reduced power consumption
Balanced propagation delays
Characterized for operation from –40° to 85°C
24 pin DIP. Manufactured by Harris.