ST 74LCX257 handbook
Contents
1. 97 74LCX257 LOW VOLTAGE CMOS QUAD 2 CHANNEL MULTIPLEXER WITH 5V TOLERANT INPUTS AND OUTPUTS 3 STATE 5V TOLERANT INPUTS AND OUTPUTS HIGH SPEED tpp 6 0 ns MAX at Voc 3V POWER DOWN PROTECTION ON INPUTS AND OUTPUTS a SYMMETRICAL OUTPUT IMPEDANCE lol lot 24mA MIN at Voc 3V PCI BUS LEVELS GUARANTEED AT 24 mA BALANCED PROPAGATION DELAYS PLH PHL OPERATING VOLTAGE RANGE Vcc OPR 2 0V to 3 6V 1 5V Data Retention PIN AND FUNCTION COMPATIBLE WITH 74 SERIES 257 m LATCH UP PERFORMANCE EXCEEDS 500mA JESD 17 m ESD PERFORMANCE HBM gt 2000V MIL STD 883 method 3015 MM gt 200V DESCRIPTION The 74LCX257 is a low voltage CMOS QUAD 2 CHANNEL MULTIPLEXER 3 STATE fabricated with sub micron silicon gate and double layer metal wiring C MOS technology It is ideal for low power and high speed 3 3V applications it can be interfaced to 5V signal environment for both inputs and outputs Figure 1 Pin Connection And IEC Logic Symbols September 2004 Table 1 Order Codes PACKAGE T amp R 74LOX257NTR TSSOP 74LCX257TTR lt is composed of four independent 2 channel multiplexers with common SELECT and ENABLE OE INPUT The 74LCX257 is a non inverting multiplexer When the ENABLE INPUT is held High all outputs become in high impedance state If SELECT INPUT is held Low A data is selected when SELECT INPUT is High B data is chosen lt has same speed performanc2. 2 4 2 4 j lo 24 mA 2 2 2 2 VoL Low Level Output 2 7 to 3 6 Io 100 uA 0 2 0 2 Voltage 27 lo 12 mA 0 4 0 4 v m lo 16 mA 0 4 0 4 i lo 24 mA 0 55 0 55 i input Leakage 2 7t03 6 V 0t05 5V 5 5 pA Current loff Power Off Leakage Vi or Va 5 5V Current 2 taa 10 e KA loz High Impedance V Vi or V Output Leakage 2 7 to 3 6 vi a ns V l 5 5 uA Current o cc loc Quiescent Supply EN Vi Vcc or GND 10 10 A Current SS or Vo 3 6 to 5 5V 10 Bl Alce loc incr per Input 2 7 to 3 6 Vin Voc 0 6V 500 500 uA 4 13 ky Table 7 Dynamic Switching Characteristics 74LCX257 Test Condition Value Ty 25 C i Symbol Parameter Vec A Unit v Min Typ Max VoLP Dynamic Low Level Quiet C 50pF 0 8 Voy Output note 1 33 Vie OV Vig 3 3V 08 y 1 Number of outputs defined as n Measured with n 1 outputs switching from HIGH to LOW or LOW to HIGH The remaining output is measured in the LOW state Table 8 AC Electrical Characteristics Test Condition Value Symbol Parameter Vec CL Re t tr 40 to 85 C 55 to 125 C Unit v PF Q ns Min Max Min Max tpLH teni Propagation Delay 2 7 1 5 6 5 1 5 6 5 2 Time A B to Y O a ta Ins oo 15 60 i tru tpy_ Propagation Delay 2 7 1 5 8 5 1 5 8 5 Time SELECT to Y g ot0a6 25 45 7 70 15 70 gt tpzLtpzu Output Enable Time 2
3. 7 1 5 8 5 1 5 8 5 2 5 a a Ms 15 70 15 70 ns tpLz tpyz Output Disable Time 2 7 1 5 6 0 1 5 6 0 O 500 2 5 3 01036 gt 15 55 15 55 tostH Output To Output 3 0 to 3 6 50 500 2 5 1 0 1 0 ns tosHL Skew Time note1 2 1 Skew is defined as the absolute value of the difference between the actual propagation delay ing in the same direction either HIGH or LOW tos H tPLHm tpuHnl tosHL tPHLm tPHLnl 2 Parameter guaranteed by design Table 9 Capacitive Characteristics or any two outputs of the same device switch Test Condition Value Ty 25 C i Symbol Parameter Vec A Unit v Min Typ Max CiN Input Capacitance 3 3 Vin 0 to Vee 7 pF Cour Output Capacitance 3 3 Vin 0 to Voc 8 pF Cpp Power Dissipation Capacitance 3 3 fin 10MHz 25 F note 1 Vin 0or Voc p 1 Cpp 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 Cpp X Vcc X fin Icc 4 per channel 4 5 13 74LCX257 Figure 4 Test Circuit PULSE GENERATOR SC08900 TEST SWITCH PLH PHL Open tpzu tp z 6V tpzu PHZ GND CL 50 pF or equivalent includes jig and probe capacitance RL R1 5002 or equivalent Rr Zour of pulse generator typi
4. cally 509 Figure 5 Waveform Propagation Delays f 1MHz 50 duty cycle SC14671 6 13 157 74LCX257 Figure 6 Waveform Output Enable And Disable Time f 1MHz 50 duty cycle ky 713 74LCX257 SO 16 MECHANICAL DATA M ell 6 9 LL 1 8 AA ZU UU UU Uo 6 0016020D 8 13 ky 74LCX257 TSSOP16 MECHANICAL DATA 0 173 0 0256 BSC 8 0 8 L 0 45 0 60 0 75 0 018 0 024 0 030 PIN 1 IDENTIFICATION 0080338D 4 9 13 74LCX257 Tape amp Reel SO 16 MECHANICAL DATA N C Y Y A A A TE Po Bo TE y O Dd D O q _ Ko AO ee Note Drawing not in scale 10 13 74LCX257 Tape amp Reel TSSOP16 MECHANICAL DATA N E Y 1 A i i RER Po Bo mo D O q l 5 Note Drawing not in scale Sts 74LCX257 Table 10 Revision History Date Revision Description of Changes 15 Sep 2004 4 Ordering Codes Revision pag 1 12 13 74LCX257 Information fur
5. e at 3 3V than 5V AC ACT family combined with a lower power consumption All inputs and outputs are equipped with protection circuits against static discharge giving them 2KV ESD immunity and transient excess voltage OE SELECT 1A 1B 2A 2B 3A 3B 4A 4B LC11710 Rev 4 1 13 74LCX257 Figure 2 Input And Output Equivalent Circuit OUTPUT O SC13540 Table 2 Pin Description PIN N SYMBOL NAME AND FUNCTION 1 SELECT Common Data Select Inputs 2 5 11 14 1A to 4A Data Inputs From Source A 3 6 10 13 1B to 4B Data Inputs From Source B 4 7 9 12 1Y to 4Y 3 State Multiplexer Outputs 15 OE 3 State Output Enable Inputs Active LOW 8 GND Ground 0V 16 Voc Positive Supply Voltage Table 3 Truth Table INPUTS OUTPUT 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 2 13 IST Figure 3 Logic Diagram This logic diagram has not be used to estimate propagation delays Table 4 Absolute Maximum Ratings 74LCX257 Symbol Parameter Value Unit Voc Supply Voltage 0 5 to 7 0 V VI DC Input Voltage 0 5 to 7 0 V Vo DC Output Voltage OFF State 0 5 to 7 0 V Vo DC Output Voltage High or Low State note 1 0 5 to Vcc 0 5 V lik DC Input Diode Current 50 mA lok DC Outp
6. nished is believed to be accurate and reliable However STMicroelectronics assumes no responsibility for the consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its use No license is granted by implication or otherwise under any patent or patent rights of STMicroelectronics Specifications mentioned in this publication are subject to change without notice This publication supersedes and replaces all information previously supplied STMicroelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics The ST logo is a registered trademark of STMicroelectronics All other names are the property of their respective owners 2004 STMicroelectronics All Rights Reserved STMicroelectronics group of companies Australia Belgium Brazil Canada China Czech Republic Finland France Germany Hong Kong India Israel Italy Japan Malaysia Malta Morocco Singapore Spain Sweden Switzerland United Kingdom United States of America www st com 1577 13 13
7. ut Diode Current note 2 50 mA lo DC Output Current 50 mA loc DC Supply Current per Supply Pin 100 mA land DC Ground Current per Supply Pin 100 mA Tstg Storage Temperature 65 to 150 C TL Lead Temperature 10 sec 300 C Absolute Maximum Ratings are those values beyond which damage to the device may occur Functional operation under these conditions is not implied 1 Io absolute maximum rating must be observed 2 Vo lt GND x 3 13 74LCX257 Table 5 Recommended Operating Conditions Symbol Parameter Value Unit Voc Supply Voltage note 1 2 0 to 3 6 V VI Input Voltage 0 to 5 5 V Vo Output Voltage OFF State 0 to 5 5 V Vo Output Voltage High or Low State 0 to Vec V lo lo High or Low Level Output Current Vcc 3 0 to 3 6V 24 mA low lo High or Low Level Output Current Vcc 2 7V 12 mA Top Operating Temperature 55 to 125 C dt dv Input Rise and Fall Time note 2 0 to 10 ns V 1 Truth Table guaranteed 1 5V to 3 6V 2 Vin from 0 8V to 2V at Voc 3 0V Table 6 DC Specifications Test Condition Value Symbol Parameter Vec 40 to 85 C 55 to 125 C Unit v Min Max Min Max Vin vn Input 20 20 y 5 7 2 T 2 7 to 3 6 IL ow Level Input 08 0 8 v Voltage VoH High Level Output 2 7 to 3 6 lo 100 pA Vcc 0 2 Vcc 0 2 Voltage 2 7 lo 12 mA 2 2 2 2 y si lo 18 mA
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ST 74LCX257 handbook