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| TECHNICAL DATA IN74AC257 Quad 2-Input Data Selector/Multiplexer with 3-State Outputs High-Speed Silicon-Gate CMOS The IN74AC257 is identical in pinout to the LS/ALS257, HC/HCT257. The device inputs are compatible with standard CMOS outputs; with pullup resistors, they are compatible with LS/ALS outputs. This device selects a (4-bit) nibble from either the A or B inputs as determined by the Select input. The nibble is presented at the outputs in noninverted from when the Output Enable pin is at a low level. A high level on the Output Enable pin switches the outputs into the highimpedance state. * Outputs Directly Interface to CMOS, NMOS, and TTL * Operating Voltage Range: 2.0 to 6.0 V * Low Input Current: 1.0 A; 0.1 A @ 25C * High Noise Immunity Characteristic of CMOS Devices * Output Source/Sink 24 mA ORDERING INFORMATION IN74AC257N Plastic IN74AC257D SOIC TA = -40 to 85 C for all packages PIN ASSIGNMENT LOGIC DIAGRAM FUNCTION TABLE Inputs Output Enable H L L PIN 16 =VCC PIN 8 = GND Select X L H Outputs Y0-Y3 Z A0-A3 B0-B3 X=don't care Z = high-impedance state A0-A3,B0-B3=the levels of the respective Nibble Inputs 356 IN74AC257 MAXIMUM RATINGS* Symbol VCC VIN VOUT IIN IOUT ICC PD Tstg TL * Parameter DC Supply Voltage (Referenced to GND) DC Input Voltage (Referenced to GND) DC Output Voltage (Referenced to GND) DC Input Current, per Pin DC Output Sink/Source Current, per Pin DC Supply Current, VCC and GND Pins Power Dissipation in Still Air, Plastic DIP+ SOIC Package+ Storage Temperature Lead Temperature, 1 mm from Case for 10 Seconds (Plastic DIP or SOIC Package) Value -0.5 to +7.0 -0.5 to VCC +0.5 -0.5 to VCC +0.5 20 50 50 750 500 -65 to +150 260 Unit V V V mA mA mA mW C C Maximum Ratings are those values beyond which damage to the device may occur. Functional operation should be restricted to the Recommended Operating Conditions. +Derating - Plastic DIP: - 10 mW/C from 65 to 125C SOIC Package: : - 7 mW/C from 65 to 125C RECOMMENDED OPERATING CONDITIONS Symbol VCC VIN, VOUT TJ TA IOH IOL tr, tf Parameter DC Supply Voltage (Referenced to GND) DC Input Voltage, Output Voltage (Referenced to GND) Junction Temperature (PDIP) Operating Temperature, All Package Types Output Current - High Output Current - Low Input Rise and Fall Time (except Schmitt Inputs) * Min 2.0 0 -40 Max 6.0 VCC 140 +85 -24 24 Unit V V C C mA mA ns/V VCC =3.0 V VCC =4.5 V VCC =5.5 V 0 0 0 150 40 25 * VIN from 30% to 70% VCC This device contains protection circuitry to guard against damage due to high static voltages or electric fields. However, precautions must be taken to avoid applications of any voltage higher than maximum rated voltages to this high-impedance circuit. For proper operation, VIN and VOUT should be constrained to the range GND(VIN or VOUT)VCC. Unused inputs must always be tied to an appropriate logic voltage level (e.g., either GND or VCC). Unused outputs must be left open. 357 IN74AC257 DC ELECTRICAL CHARACTERISTICS(Voltages Referenced to GND) VCC Symbol VIH Parameter Minimum High-Level Input Voltage Maximum Low Level Input Voltage Minimum High-Level Output Voltage Test Conditions VOUT=0.1 V or VCC-0.1 V V 3.0 4.5 5.5 3.0 4.5 5.5 3.0 4.5 5.5 3.0 4.5 5.5 3.0 4.5 5.5 3.0 4.5 5.5 5.5 5.5 Guaranteed Limits 25 C 2.1 3.15 3.85 0.9 1.35 1.65 2.9 4.4 5.4 2.56 3.86 4.86 0.1 0.1 0.1 0.36 0.36 0.36 0.1 0.5 -40C to 85C 2.1 3.15 3.85 0.9 1.35 1.65 2.9 4.4 5.4 2.46 3.76 4.76 0.1 0.1 0.1 0.44 0.44 0.44 1.0 5.0 A A V Unit V VIL VOUT=0.1 V or VCC-0.1 V V VOH IOUT -50 A V * VIN= VIH or VIL IOH=-12 mA IOH=-24 mA IOH=-24 mA VOL Maximum Low-Level Output Voltage IOUT 50 A VIN=VIH or VIL IOL=12 mA IOL=24 mA IOL=24 mA IIN IOZ Maximum Input Leakage Current Maximum ThreeState Leakage Current +Minimum Dynamic Output Current +Minimum Dynamic Output Current Maximum Quiescent Supply Current (per Package) VIN=VCC or GND VIN(OE)= VIH or VIL VIN =VCC or GND VOUT =VCC or GND VOLD=1.65 V Max VOHD=3.85 V Min VIN=VCC or GND * IOLD IOHD ICC 5.5 5.5 5.5 8.0 75 -75 80 mA mA A All outputs loaded; thresholds on input associated with output under test. +Maximum test duration 2.0 ms, one output loaded at a time. Note: IIN and ICC @ 3.0 V are guaranteed to be less than or equal to the respective limit @ 5.5 V VCC * 358 IN74AC257 AC ELECTRICAL CHARACTERISTICS(CL=50pF, Input tr=tf=3.0 ns) VCC* Symbol Parameter V Guaranteed Limits 25 C Min tPLH tPHL tPLH tPHL tPZH tPZL tPHZ tPLZ CIN Propagation Delay, Nibble A or B to Output Y (Figure 1) Propagation Delay, Nibble A or B to Output Y (Figure 1) Propagation Delay, Select to Output Y (Figure 2) Propagation Delay, Select to Output Y (Figure 2) Propagation Delay, Output Enable to Output Y (Figure 3) Propagation Delay, Output Enable to Output Y (Figure 3) Propagation Delay, Output Enable to Output Y (Figure 3) Propagation Delay, Output Enable to Output Y (Figure 3) Maximum Input Capacitance 3.3 5.0 3.3 5.0 3.3 5.0 3.3 5.0 3.3 5.0 3.3 5.0 3.3 5.0 3.3 5.0 5.0 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 4.5 Max 8.5 6.0 8.5 6.0 10.5 7.5 10.5 7.5 9.5 7.5 9.0 8.5 10.0 9.0 9.0 8.0 -40C to 85C Min 1.0 1.0 1.0 1.0 1.5 1.0 1.5 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 4.5 Max 9.0 7.0 9.0 7.0 11.5 8.5 11.5 8.5 10.5 8.5 10.0 9.5 11.0 10.0 10.0 9.0 ns ns ns ns ns ns ns ns pF Unit Typical @25C,VCC=5.0 V CPD * Power Dissipation Capacitance 50 pF Voltage Range 3.3 V is 3.3 V 0.3 V Voltage Range 5.0 V is 5.0 V 0.5 V Figure 1. Switching Waveforms Figure 2. Switching Waveforms 359 IN74AC257 Figure 3. Switching Waveforms EXPANDED LOGIC DIAGRAM 360 |
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