ST 74VHCT245A handbook
Contents
1. ddd 0 100 0 004 D hx45 r i E El la ane it UN Mote B a ddd c SEATING 20 1 PLANE C 0 25 mm GAGE PLANE PIN_1 IDENTIFICATION 0016022D 8 13 ky 74VHCT245A TSSOP20 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 0087225C 4 9 13 74VHCT245A Tape 8 Reel SO 20 MECHANICAL DATA P 11 9 12 1 0 468 0 476 N C Y Y A A A aE Po Bo ro Le O l i A j Ko AO P ml Note Drawing not in scale 10 13 74VHCT245A Tape amp Reel TSSOP20 MECHANICAL DATA P 11 9 12 1 0 468 0 476 N C Y 1 A i i aT Po Bo y OD O 2G l Ko AO Lok Not2. SZA 74VHCT245A OCTAL BUS TRANSCEIVER 3 STATE HIGH SPEED tpp 4 5 ns TYP at Vcc 5V LOW POWER DISSIPATION Icc 4 pA MAX at Ta 25 C COMPATIBLE WITH TTL OUTPUTS Vin 2V MIN Vi 0 8V MAX POWER DOWN PROTECTION ON INPUTS 8 OUTPUTS a SYMMETRICAL OUTPUT IMPEDANCE llo lo 8 mA MIN BALANCED PROPAGATION DELAYS tPLH PHL OPERATING VOLTAGE RANGE Voc OPR 4 5V to 5 5V a PIN AND FUNCTION COMPATIBLE WITH 74 SERIES 245 a IMPROVED LATCH UP IMMUNITY a LOW NOISE Volp 0 9V MAX DESCRIPTION The 74VHCT245A is an advanced high speed CMOS OCTAL BUS TRANSCEIVER 3 STATE fabricated with sub micron silicon gate and double layer metal wiring CMOS technology This IC is intended for two way asynchronous communication between data busses the Figure 1 Pin Connection And IEC Logic Symbols d a IAE pl En ER ER SP December 2004 Table 1 Order Codes PACKAGE T amp R TAVACT2ASAMTR TSSOP 74VHCT245ATTR direction of data transmission_is determined by DIR input The enable input G can be used to disable the device so that the busses are effectively isolated All inputs and outputs are equipped with protection circuits against static discharge giving them 2KV ESD immunity and transient excess voltage All floating bus terminals during High Z State must be held HIGH or LOW G3 3EN1 BA 3EN2 AB Le19911 Rev 4 1 13 74VHCT
3. I c opr Cpp X Voc X fin Ioc 8 per circuit Table 4 DYNAMIC SWITCHING CHARACTERISTICS Test Condition Value Symbol Parameter Vec Ta 25 C 40 to 85 C 55 to 125 C Unit V Min Typ Max Min Max Min Max Vo p Dynamic Low 0 6 0 9 Voltage Quiet 5 0 Volv Output note 1 2 0 9 0 6 Dynamic High Viho Voltage Input 5 0 C 50 pF 2 0 V note 1 3 Dynamic Low Vio Voltage Input 5 0 0 8 note 1 3 1 Worst case package 2 Max number of outputs defined as n Data inputs are driven OV to 3 0V n 1 outputs switching and one output at GND 3 Max number of data inputs n switching n 1 switching OV to 3 0V Inputs under test switching 3 0V to threshold Vp OV to threshold Vinp s f 1MHz 4 5 13 74VHCT245A Figure 5 Test Circuit PULSE GENERATOR sc11700 TEST SWITCH PLH PHL Open tez tPLZ Voc tpzH PHZ GND CL 15 50pF or equivalent includes jig and probe capacitance Ri Ry 1KQ or equivalent R7 Zour of pulse generator typically 509 Figure 6 Waveform Propagation Delays f 1MHz 50 duty cycle Bn or An C12550 6 13 ky 74VHCT245A Figure 7 Waveform Output Enable And Disable Time f 1 MHz 50 duty cycle 5012560 ky 713 74VHCT245A SO 20 MECHANICAL DATA
4. 1 35 1 5 1 5 mA Current or GND lopp Output Leakage a Current 0 Vout 5 5V 0 5 5 0 5 0 uA Table 7 AC Electrical Characteristics Input t t 3ns Test Condition Value Symbol Parameter Veo CL Ta 25 C 40 to 85 C 55 to 125 C Unit V PF Min Typ Max Min Max Min Max tpl Propagation Delay 5 0 15 45 7 5 1 0 85 1 0 10 0 ng tru Time 5 0 50 53 8 7 1 0 95 1 0 11 0 tpz_ Output Enable 5 0 15 9 0 13 8 1 0 15 0 1 0 16 0 RL 1KQ tezy Time 5 0 50 97 148 10 16 0 10 17 0 t Output Disabl es E 5 0 50 RL 1Ko 10 0 154 1 0 165 1 0 17 5 ns tpuz ime tostH Output to Output tosuL Skew Time note 1 5 0 50 1 0 1 0 1 0 ns Voltage range is 5 0V 0 5V Note 1 Parameter guaranteed by design tsoLH ltoLHm toLHnl tsoHL lpHLm toHtnl 4 13 4 74VHCT245A Table 8 Capacitive Characteristics Test Condition Value Symbol Parameter Ta 25 C 40 to 85 C 55 to 125 C Unit Min Typ Max Min Max Min Max Cin Input Capacitance 6 10 10 10 pF Bus Input Cro Capacitance 2 pF Cpp Power Dissipation Capacitance 18 pF note 1 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
5. 245A Figure 2 Input Output Equivalent Circuit I O An Bn O 4 OVERVOLT CONTROL Table 2 Pin Description C12630 PIN N SYMBOL NAME AND FUNCTION 1 DIR Directional Control 2 3 4 5 6 A1 to A8 Data Inputs Outputs 7 8 9 18 17 16 B1 to B8 Data Inputs Outputs 15 14 13 12 11 GND 19 G Enable Input 10 GND Ground 0V J 20 Voc Positive Supply Voltage C12500 Table 3 Truth Table INPUTS FUNCTION OUTPUT G DIR A BUS B BUS L L OUTPUT INPUT A B L H INPUT OUTPUT B A H X Z Z Z X Dont Care Z High Impedance 2 13 4 74VHCT245A Table 4 Absolute Maximum Ratings Symbol Parameter Value Unit Voc Supply Voltage 0 5 to 7 0 V VI DC Input Voltage DIR G 0 5 to 7 0 V Vio DC BUS I O Voltage see note 1 0 5 to 7 0 V Vio DC BUS I O Voltage see note 2 0 5 to Vcc 0 5 V lik DC Input Diode Current 20 mA lok DC Output Diode Current 20 mA lo DC Output Current 25 mA Icc Or lenp DC Vec or Ground Current 75 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 Output in OFF State 2 High or Low State ly absolute ma
6. e Drawing not in scale ky 11 13 74VHCT245A Table 9 Revision History Date Revision Description of Changes 16 Dec 2004 4 Order Codes Revision pag 1 12 13 74VHCT245A Information furnished 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 157 13 13
7. ximum rating must be observed Table 5 Recommended Operating Conditions Symbol Parameter Value Unit Voc Supply Voltage 4 5 to 5 5 V VI Input Voltage 0 to 5 5 V Vio BUS 1 O Voltage see note 1 0 to 5 5 V Vio BUS I O Voltage see note 2 0 to Vec V Top Operating Temperature 55 to 125 C dt dv Input Rise and Fall Time see note 3 Vcc 5 0 0 5V 0 to 20 ns V 1 Output in OFF State 2 High or Low State ly absolute maximum rating must be observed 3 Vin from 0 8V to 2V 4 3 13 74VHCT245A Table 6 DC Specifications Test Condition Value Symbol Parameter Vec Ta 25 C 40 to 85 C 55 to 125 C Unit v Min Typ Max Min Max Min Max Vin High Level Input 4 5to Voltage 5 5 2 2 y Vit Low Level Input 4 5 to Voltage 55 0 8 0 8 0 8 V Vo High Level Output 4 5 lo 50 pA 4 4 45 4 4 4 4 A voltage 4 5 lo 8 mA 3 94 3 8 3 7 Vo Low Level Output 4 5 lo 50 pA 0 0 0 1 0 1 0 1 y Voltage 45 lo 8 mA 0 36 0 44 0 55 loz High Impedance Vis Vi or Wi A A Output Leakage 5 5 Va 0V to 5 5V 0 25 2 5 2 5 vA Current o j l Input Leakage 0 to y 4 rai 55 i 5 5V or GND 04 1 0 1 0 uA loc Quiescent Supply _ Current 5 5 Vi Voc or GND 4 40 40 uA loc Additional Worst One Input at 3 4V Case Supply 5 5 other input at Voc
Download Pdf Manuals
Related Search
ST 74VHCT245A handbook