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 µA; 0.1 µA @ 25°C • 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 PIN 16 =VCC PIN 8 = GND 356 Outputs Output Enable Select Y0-Y3 H X Z L L A0-A3 L H B0-B3 X=don’t care Z = high-impedance state A0-A3,B0-B3=the levels of the respective Nibble Inputs IN74AC257 MAXIMUM RATINGS* Symbol Parameter Value Unit -0.5 to +7.0 V VCC DC Supply Voltage (Referenced to GND) VIN DC Input Voltage (Referenced to GND) -0.5 to VCC +0.5 V DC Output Voltage (Referenced to GND) -0.5 to VCC +0.5 V DC Input Current, per Pin ±20 mA IOUT DC Output Sink/Source Current, per Pin ±50 mA ICC DC Supply Current, VCC and GND Pins ±50 mA PD Power Dissipation in Still Air, Plastic DIP+ SOIC Package+ 750 500 mW -65 to +150 °C 260 °C VOUT IIN Tstg TL Storage Temperature Lead Temperature, 1 mm from Case for 10 Seconds (Plastic DIP or SOIC Package) * 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 125°C SOIC Package: : - 7 mW/°C from 65° to 125°C RECOMMENDED OPERATING CONDITIONS Symbol VCC VIN, VOUT DC Supply Voltage (Referenced to GND) DC Input Voltage, Output Voltage (Referenced to GND) TJ Junction Temperature (PDIP) TA Operating Temperature, All Package Types IOH Output Current - High IOL Output Current - Low tr, tf * Parameter Input Rise and Fall Time (except Schmitt Inputs) * Min Max Unit 2.0 6.0 V 0 VCC V 140 °C +85 °C -24 mA 24 mA 150 40 25 ns/V -40 VCC =3.0 V VCC =4.5 V VCC =5.5 V 0 0 0 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 Guaranteed Limits V 25 °C -40°C to 85°C Unit VOUT=0.1 V or VCC-0.1 V 3.0 4.5 5.5 2.1 3.15 3.85 2.1 3.15 3.85 V Maximum Low Level Input Voltage VOUT=0.1 V or VCC-0.1 V 3.0 4.5 5.5 0.9 1.35 1.65 0.9 1.35 1.65 V Minimum High-Level Output Voltage IOUT ≤ -50 µA 3.0 4.5 5.5 2.9 4.4 5.4 2.9 4.4 5.4 V 3.0 4.5 5.5 2.56 3.86 4.86 2.46 3.76 4.76 3.0 4.5 5.5 0.1 0.1 0.1 0.1 0.1 0.1 VIN=VIH or VIL IOL=12 mA IOL=24 mA IOL=24 mA 3.0 4.5 5.5 0.36 0.36 0.36 0.44 0.44 0.44 Symbol Parameter VIH Minimum High-Level Input Voltage VIL VOH Test Conditions * VIN= VIH or VIL IOH=-12 mA IOH=-24 mA IOH=-24 mA VOL Maximum Low-Level Output Voltage IOUT ≤ 50 µA V * IIN Maximum Input Leakage Current VIN=VCC or GND 5.5 ±0.1 ±1.0 µA IOZ Maximum ThreeState Leakage Current VIN(OE)= VIH or VIL VIN =VCC or GND VOUT =VCC or GND 5.5 ±0.5 ±5.0 µA IOLD +Minimum Dynamic Output Current VOLD=1.65 V Max 5.5 75 mA IOHD +Minimum Dynamic Output Current VOHD=3.85 V Min 5.5 -75 mA ICC Maximum Quiescent Supply Current (per Package) VIN=VCC or GND 5.5 80 µA * 8.0 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 Guaranteed Limits 25 °C V -40°C to 85°C Min Max Min Max Unit tPLH Propagation Delay, Nibble A or B to Output Y (Figure 1) 3.3 5.0 1.5 1.5 8.5 6.0 1.0 1.0 9.0 7.0 ns tPHL Propagation Delay, Nibble A or B to Output Y (Figure 1) 3.3 5.0 1.5 1.5 8.5 6.0 1.0 1.0 9.0 7.0 ns tPLH Propagation Delay, Select to Output Y (Figure 2) 3.3 5.0 1.5 1.5 10.5 7.5 1.5 1.0 11.5 8.5 ns tPHL Propagation Delay, Select to Output Y (Figure 2) 3.3 5.0 1.5 1.5 10.5 7.5 1.5 1.0 11.5 8.5 ns tPZH Propagation Delay, Output Enable to Output Y (Figure 3) 3.3 5.0 1.5 1.5 9.5 7.5 1.0 1.0 10.5 8.5 ns tPZL Propagation Delay, Output Enable to Output Y (Figure 3) 3.3 5.0 1.5 1.5 9.0 8.5 1.0 1.0 10.0 9.5 ns tPHZ Propagation Delay, Output Enable to Output Y (Figure 3) 3.3 5.0 1.5 1.5 10.0 9.0 1.0 1.0 11.0 10.0 ns tPLZ Propagation Delay, Output Enable to Output Y (Figure 3) 3.3 5.0 1.5 1.5 9.0 8.0 1.0 1.0 10.0 9.0 ns CIN Maximum Input Capacitance 5.0 4.5 4.5 pF Typical @25°C,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