74F251A Datasheet | Philips Semiconductors

FEATURES - High speed 8-to-1 multiplexing - On chip decoding - Multifunction capability - Inverting and Non-Inverting outputs - Both outputs are 3-State for further multiplexer expansion DESCRIPTION The 74F251A is a logic implementation of a single 8-position switch with the switch position controlled by the state of three Select (S0, S1, S2) inputs. True (Y) and plementary (Y) outputs are both provided. The output enable (OE) is active Low. When OE is High, both outputs are in High impedance state, allowing multiple output connections to a mon bus without driving nor loading the bus significantly. All but one device must be in High impedance state to avoid high currents that would exceed the maximum ratings when the outputs of the 3-State devices are tied together. When the output of more than one device is tied together the user must ensure that there is no overlap in the active Low portion of the output enable voltages. PIN CONFIGURATION I3 I2 I1 I0 Y Y OE GND 1 2 3 4 5 6 7 8 16 15 14 13 12 11 10 9 VCC I4 I5 I6 I7 S0 S1 S2 SF00778 TYPE 74F251A TYPICAL PROPAGATION DELAY 4.5ns TYPICAL SUPPLY CURRENT (TOTAL) 19m A ORDERING INFORMATION ORDER CODE DESCRIPTION MERCIAL RANGE VCC = 5V ±10%, Tamb = 0°C to +70°C N74F251AN N74F251AD PKG DWG # SOT38-4 SOT162-1 16-pin plastic DIP 16-pin plastic SO INPUT AND OUTPUT LOADING AND FAN-OUT TABLE PINS I0- I7 S0- S2 OE Y, Y Data inputs Select inputs Output Enable input (active Low) Data outputs DESCRIPTION 74F (U.L.) HIGH/LOW 1.0/1.0 1.0/1.0 1.0/1.0 150/40 LOAD VALUE HIGH/LOW 20µA/0.6m A 20µA/0.6m A 20µA/0.6m A 3m A/24m A NOTE: One (1.0) FAST unit load is defined as: 20µA in the High state and 0.6m A in the Low state. LOGIC SYMBOL 4 3 2 1 15 14 13 12 IEC/IEEE SYMBOL 7 11 10 I0 I1 I2 I3 I4 I5 I6 I7 9 4 3 2 1 6 0 G 2 0 7 5 MUX 11 10 9 7 S0 S1 S2 OE Y Y 15 14 13 VCC = Pin 16 GND = Pin 8 SF00779 SF00780 1996 Jan 05 853- 0358 16191 Philips...