The is a quad 2-input multiplexer with TRI-STATE outputs. Four bits of data from two sources can be selected using a Common Data Select input. The four outputs present the selected data in true (noninverted) form. The outputs may be switched to a high impedance state by placing a logic HIGH on the common Output Enable (OE) input, allowing the outputs to interface directly with bus-oriented systems.Features
ICC and IOZ reduced by 50% Multiplexer expansion by tying outputs together Noninverting TRI-STATE outputs Outputs source/sink mA 'ACT257 has TTL-compatible inputs Standard Military Drawing (SMD) 'ACT257: 5962-89689
Description Common Data Select Input TRI-STATE Output Enable Input Data Inputs from Source 0 Data Inputs from Source 1 TRI-STATE Multiplexer Outputs
TRI-STATE is a registered trademark of National Semiconductor Corporation. FACTTM is a trademark of Fairchild Semiconductor Corporation.
The 'AC/'ACT257 is quad 2-input multiplexer with TRI-STATE outputs. It selects four bits of data from two sources under control of a Common Data Select input. When the Select input is LOW, the I0x inputs are selected and when Select is HIGH, the I1x inputs are selected. The data on the selected inputs appears at the outputs in true (noninverted) form. The device is the logic implementation 4-pole, 2-position switch where the position of the switch is determined by the logic levels supplied to the Select input. The logic equations for the outputs are shown below: Za = OE Zb = OE Zc = OE Zd = OE I0d S) When the Output Enable (OE) is HIGH, the outputs are forced to a high impedance state. If the outputs are tied together, all but one device must be in the high impedance state to avoid high currents that would exceed the maximum ratings. Designers should ensure the Output Enable signals to TRI-STATE devices whose outputs are tied together are designed so there is no overlap.H = HIGH Voltage Level L = LOW Voltage Level X = Immaterial Z = High Impedance
Please note that this diagram is provided only for the understanding of logic operations and should not be used to estimate propagation delays.
If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Supply Voltage (VCC) DC Input Diode Current (IIK) VI = VCC +0.5V DC Input Voltage (VI) DC Output Diode Current (IOK) VO = VCC +0.5V DC Output Voltage (VO) DC Output Source or Sink Current (IO) DC VCC or Ground Current Per Output Pin (ICC or IGND) Storage Temperature (TSTG) Junction Temperature (TJ) CDIP -0.5V to VCC -0.5V to VCC +0.5V
Supply Voltage (VCC) 'AC 'ACT Input Voltage (VI) Output Voltage (VO) Operating Temperature (TA) 54AC/ACT Minimum Input Edge Rate (V/t) 'AC Devices VIN from 70% of VCC 4.5V, 5.5V Minimum Input Edge Rate (V/t) 'ACT Devices VIN from to 2.0V VCC 0V to VCC 0V to VCC to +125�C
Note 1: Absolute maximum ratings are those values beyond which damage to the device may occur. The databook specifications should be met, without exception, to ensure that the system design is reliable over its power supply, temperature, and output/input loading variables. National does not recommend operation of FACTTM circuits outside databook specifications.
Symbol Parameter VCC (V) to +125�C Guaranteed Limits VIH Minimum High Level Input Voltage VIL Maximum Low Level Input Voltage VOH Minimum High Level Output Voltage (Note 2) VIN = VIL or VIH 4.5 5.5 VOL Maximum Low Level Output Voltage (Note 2) VIN = VIL or VIH 4.5 5.5 IIN Maximum Input Leakage Current V �A IOL VI = VCC, GND V IOH -24 mA IOUT �A V IOUT �A V VOUT 0.1V or VCC 0.1V V VOUT 0.1V or VCC - 0.1V Units Conditions