74AC257 QUAD 2 CHANNEL MULTIPLEXER (3-STATE) ■ ■ ■ ■ ■ ■ ■ ■ ■ HIGH SPEED: tPD =4.5 ns (TYP.) at VCC = 5V LOW POWER DISSIPATION: ICC = 8 µA (MAX.) at TA = 25 oC HIGH NOISE IMMUNITY: VNIH = VNIL = 28% VCC (MIN.) 50Ω TRANSMISSION LINE DRIVING CAPABILITY SYMMETRICAL OUTPUT IMPEDANCE: |IOH| = IOL = 24 mA (MIN) BALANCED PROPAGATION DELAYS: tPLH ≅ tPHL OPERATING VOLTAGE RANGE: VCC (OPR) = 2V to 6V PIN AND FUNCTION COMPATIBLE WITH 74 SERIES 257 IMPROVED LATCH-UP IMMUNITY DESCRIPTION The AC257 is an advanced high-speed CMOS QUAD 2 CHANNEL MULTIPLEXER (3-STATE) fabricated with sub-micron silicon gate and double-layer metal wiring C2MOS technology. It is ideal for low power applications mantaining high speed operation similar to equivalent Bipolar Schottky TTL. B M (Plastic Package) (Micro Package) ORDER CODES : 74AC257B These IC’s are composed of an independent 2 channel multiplexer with common SELECT and ENABLE INPUT. The AC257 is a non inverting multiplexer. When the ENABLE INPUT is held ”High”, outputs of both IC’s become high impedance state. If SELECT INPUT is held ”Low”, ”A” data is selected, when SELECT INPUT is ”High”, ”B” data is chosen. All inputs and outputs are equipped with protection circuits against static discharge, giving them 2KV ESD immunity and transient excess voltage. PIN CONNECTION AND IEC LOGIC SYMBOLS April 1997 1/10 74AC257 INPUT AND OUTPUT EQUIVALENT CIRCUIT PIN DESCRIPTION PIN No SYMBOL NAME AND F UNCTIO N 1 SELECT Common Data Select Input 2, 5, 14, 11 1A to 4A Data Input From Source A 3, 6, 13, 10 1B to 4B Data Inputs from Source B 4, 7, 12, 9 1Y to 4Y 15 OE 8 GND Ground (0V) 16 VCC Positive Supply Voltage 3 State Multiplexer Outputs 3 State Output Enable Inputs (Active LOW) TRUTH TABLE INPUT S OE SELECT A B Y H X X X Z L L L X L L L H X H L H X L L L H X H H X = DON’T CARE Z = HIGH IMPEDANCE LOGIC DIAGRAM This logic diagram has not be used to estimate propagation delays 2/10 OUT PUT S 74AC257 ABSOLUTE MAXIMUM RATINGS Symbol VCC Parameter Supply Voltage Value Unit -0.5 to +7 V VI DC Input Voltage -0.5 to VCC + 0.5 V VO DC Output Voltage -0.5 to VCC + 0.5 V IIK DC Input Diode Current ± 20 mA IOK DC Output Diode Current ± 20 mA IO DC Output Current ± 50 mA ± 200 mA ICC or IGND DC VCC or Ground Current Tstg Storage Temperature TL Lead Temperature (10 sec) -65 to +150 o C 300 o C Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these condition is not implied. RECOMMENDED OPERATING CONDITIONS Symbol VCC Parameter Supply Voltage Value Un it 2 to 6 V V VI Input Voltage 0 to VCC VO Output Voltage 0 to VCC Top dt/dv Operating Temperature: Input Rise and Fall Time VCC = 3.0, 4.5 or 5.5 V(note 1) -40 to +85 8 V o C ns/V 1) VIN from 30% to 70% of VCC 3/10 74AC257 DC SPECIFICATIONS Symbol Parameter Test Con dition s VIH High Level Input Voltage 3.0 4.5 VO = 0.1 V or VCC - 0.1 V 5.5 VIL Low Level Input Voltage 3.0 4.5 Value T A = 25 oC V CC (V) Min. Typ. 2.1 1.5 2.1 3.15 2.25 3.15 3.85 2.75 VO = 0.1 V or VCC - 0.1 V 5.5 VOH High Level Output Voltage 3.0 4.5 5.5 Low Level Output Voltage VI = V IH or V IL Max. Min . Max. V 3.85 1.5 0.9 0.9 2.25 1.35 1.35 2.75 1.65 1.65 I O=-50 µA 2.9 2.99 2.9 IO=-50 µA 4.4 4.49 4.4 IO=-50 µA 5.4 5.49 5.4 IO=-12 mA 2.56 2.46 IO=-24 mA 3.86 3.76 5.5 IO=-24 mA 4.86 3.0 IO=50 µA 0.002 0.1 0.1 IO=50 µA 0.001 0.1 0.1 IO=50 µA 0.001 0.1 0.1 IO=12 mA 0.36 0.44 4.5 IO=24 mA 0.36 0.44 5.5 IO=24 mA 0.36 0.44 4.5 5.5 3.0 V I (*) = V IH or V IL V V 4.5 3.0 VOL (*) Unit -40 to 85 o C 4.76 V Input Leakage Current 5.5 VI = VCC or GND ±0.1 ±1 µA IOZ 3 State Output Leakage Current 5.5 VI = VIH or VIL VO = VCC or GND ±0.5 ±5 µA ICC Quiescent Supply Current 5.5 VI = VCC or GND 8 80 µA IOLD Dynamic Output Current (note 1, 2) 5.5 VOLD = 1.65 V max 75 mA VOHD = 3.85 V min -75 mA II IOHD 1) Maximum test duration 2ms, one output loaded at time 2) Incident wave switching is guaranteed on transmission lines with impedances as low as 50 Ω. (*) All outputs loaded. 4/10 74AC257 AC ELECTRICAL CHARACTERISTICS (CL = 50 pF, RL = 500 Ω, Input tr = t f =3 ns) Symbol Parameter T est Cond ition V CC (V) (*) Value T A = 25 oC -40 to 85 o C Min. Typ. Max. Min . Max. tPLH tPHL Propagation Delay Time A,B to Y 3.3 5.0(**) 1.5 1.5 tPLH tPHL Propagation Delay Time SEL to Y 3.3(*) 5.0 (**) tPZL tPZH Output Enable Time tPLZ tPHZ Output Disable Time 3.3 5.0(**) Unit 5.5 4.5 8.5 6 1.5 1.5 9 7 1.5 7 10.5 1.5 11.5 1.5 5.5 7.5 1.5 8.5 3.3(*) 5.0(**) 1.5 1.5 5.5 4.5 9 7.5 1.5 1.5 10 8.5 ns (*) 1.5 1.5 7 5.5 10 9 1.5 1.5 11 10 ns ns ns (*) Voltage range is 3.3V ± 0.3V (**) Voltage range is 5V ± 0.5V CAPACITIVE CHARACTERISTICS Symbol Parameter Test Con dition s V CC (V) Output Capacitance 5.0 CIN Input Capacitance C PD Power Dissipation Capacitance (note 1) C OUT Value o T A = 25 C Min. Typ. Max. Unit o -40 to 85 C Min . Max. 8 pF 5.0 4 pF 5.0 20 pF 1) CPD is defined as the value of the IC’s internal equivalent capacitance which is calculated from the operating current consumption without load. (Refer to Test Circuit). Average operating current can be obtained by the following equation. ICC(opr) = CPD • VCC • fIN + ICC/n (per circuit) TEST CIRCUIT TEST SWITCH t PLH, tPHL Open t PZL, tPLZ 2VCC t PZH, tPHZ Open CL = 50 pF or equivalent (includes jig and probe capacitance) RL = R1 = 500Ω or equivalent RT =ZOUT of pulse generator (typically 50Ω) 5/10 74AC257 WAVEFORM 1: PROPAGATION DELAYS FOR INVERTING CONDITIONS (f=1MHz; 50% duty cycle) WAVEFORM 2: PROPAGATION DELAYS FOR NON-INVERTING CONDITIONS (f=1MHz; 50% duty cycle) 6/10 74AC257 WAVEFORM 3: OUTPUT ENABLE AND DISABLE TIME (f=1MHz; 50% duty cycle) 7/10 74AC257 Plastic DIP16 (0.25) MECHANICAL DATA mm DIM. MIN. a1 0.51 B 0.77 TYP. inch MAX. MIN. TYP. MAX. 0.020 1.65 0.030 0.065 b 0.5 0.020 b1 0.25 0.010 D 20 0.787 E 8.5 0.335 e 2.54 0.100 e3 17.78 0.700 F 7.1 0.280 I 5.1 0.201 L Z 3.3 0.130 1.27 0.050 P001C 8/10 74AC257 SO16 MECHANICAL DATA mm DIM. MIN. TYP. A a1 inch MAX. MIN. TYP. 1.75 0.1 0.068 0.2 a2 MAX. 0.004 0.007 1.65 0.064 b 0.35 0.46 0.013 0.018 b1 0.19 0.25 0.007 0.010 C 0.5 0.019 c1 45 (typ.) D 9.8 E 5.8 10 0.385 6.2 0.228 0.393 0.244 e 1.27 0.050 e3 8.89 0.350 F 3.8 4.0 0.149 0.157 G 4.6 5.3 0.181 0.208 L 0.5 1.27 0.019 0.050 M S 0.62 0.024 8 (max.) P013H 9/10 74AC257 Information furnished is believed to be accurate and reliable. However, SGS-THOMSON Microelectronics assumes no responsability for the consequences of use of such information nor for any infringement of patents or other rights of third parties which may results from its use. No license is granted by implication or otherwise under any patent or patent rights of SGS-THOMSON Microelectronics. Specifications mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied. SGS-THOMSON Microelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of SGS-THOMSON Microelectonics. 1997 SGS-THOMSON Microelectronics - Printed in Italy - All Rights Reserved SGS-THOMSON Microelectronics GROUP OF COMPANIES Australia - Brazil - Canada - China - France - Germany - Hong Kong - Italy - Japan - Korea - Malaysia - Malta - Morocco - The Netherlands Singapore - Spain - Sweden - Switzerland - Taiwan - Thailand - United Kingdom - U.S.A . 10/10