74AC245 OCTAL BUS TRANSCEIVER WITH 3 STATE OUTPUTS (NON INVERTED) ■ ■ ■ ■ ■ ■ ■ ■ ■ HIGH SPEED: tPD = 4.5ns (TYP.) at VCC = 5V LOW POWER DISSIPATION: ICC = 4µA(MAX.) at TA=25°C HIGH NOISE IMMUNITY: VNIH = V NIL = 28 % VCC (MIN.) 50Ω TRANSMISSION LINE DRIVING CAPABILITY SYMMETRICAL OUTPUT IMPEDANCE: |IOH| = IOL = 24mA (MIN) BALANCED PROPAGATION DELAYS: tPLH ≅ tPHL OPERATING VOLTAGE RANGE: VCC (OPR) = 2V to 6V PIN AND FUNCTION COMPATIBLE WITH 74 SERIES 244 IMPROVED LATCH-UP IMMUNITY DESCRIPTION The 74AC245 is an advanced high-speed CMOS OCTAL BUS TRANSCEIVER (3-STATE) fabricated with sub-micron silicon gate and double-layer metal wiring C2MOS tecnology. This IC is intended for two-way asynchronous communication between data buses and the direction of data transmission is determined by DIP SOP TSSOP ORDER CODES PACKAGE TUBE DIP SOP TSSOP 74AC245B 74AC245M T&R 74AC245MTR 74AC245TTR DIR input. The enable input G can be used to disable the device so that the buses are effectively isolated.. All floating bus terminals during HIGH-Z state must be held HIGH or LOW 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 2001 1/9 74AC245 INPUT AND OUTPUT EQUIVALENT CIRCUIT PIN DESCRIPTION PIN No SYMBOL 1 2, 3, 4, 5, 6, 7, 8, 9 18, 17, 16, 15, 14, 13, 12, 11 19 10 20 DIR A1 to A8 Directional Control Data Inputs/Outputs B1 to B8 Data Inputs/Outputs G GND VCC NAME AND FUNCTION Output Enable Input Ground (0V) Positive Supply Voltage TRUTH TABLE INPUTS FUNCTION OUTPUT G DIR A BUS B BUS Yn L L H L H X OUTPUT INPUT Z INPUT OUTPUT Z A=B B=A Z X : Don’t Care Z : High Impedance 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 ± 20 V mA ± 20 mA ± 50 mA ± 400 mA IIK DC Input Diode Current IOK DC Output Diode Current IO DC Output Current ICC or IGND DC VCC or Ground Current Tstg Storage Temperature TL Lead Temperature (10 sec) -65 to +150 °C 300 °C Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these conditions is not implied. RECOMMENDED OPERATING CONDITIONS Symbol VCC Parameter Supply Voltage VI Input Voltage VO Output Voltage Top Operating Temperature dt/dv Input Rise and Fall Time VCC = 3.0, 4.5 or 5.5V (note 1) 1) VIN from 30% to 70% of V CC 2/9 Value Unit 2 to 6 V 0 to VCC V 0 to VCC V -55 to 125 °C 8 ns/V 74AC245 DC SPECIFICATIONS Test Condition Symbol VIH VIL VOH VOL II Ioz ICC IOLD IOHD Parameter High Level Input Voltage Low Level Input Voltage High Level Output Voltage Low Level Output Voltage Input Leakage Current High Impedance Output Leakage Current Quiescent Supply Current Dynamic Output Current (note 1, 2) TA = 25°C VCC (V) 3.0 4.5 5.5 3.0 4.5 5.5 Value VO = 0.1 V or VCC-0.1V Min. Typ. 2.1 3.15 3.85 1.5 2.25 2.75 1.5 2.25 2.75 VO = 0.1 V or VCC-0.1V Max. -40 to 85°C -55 to 125°C Min. Min. Max. 2.1 3.15 3.85 0.9 1.35 1.65 Max. 2.1 3.15 3.85 0.9 1.35 1.65 V 0.9 1.35 1.65 3.0 IO=-50 µA 2.9 2.99 2.9 2.9 4.5 IO=-50 µA 4.4 4.49 4.4 4.4 5.5 IO=-50 µA 5.4 5.49 5.4 5.4 3.0 IO=-12 mA 2.56 2.46 2.4 4.5 IO=-24 mA 3.86 3.76 3.7 5.5 IO=-24 mA 4.86 4.76 4.7 Unit V V 3.0 IO=50 µA 0.002 0.1 0.1 0.1 4.5 IO=50 µA 0.001 0.1 0.1 0.1 5.5 IO=50 µA 0.001 0.1 0.1 0.1 3.0 IO=12 mA 0.36 0.44 0.5 4.5 IO=24 mA 0.36 0.44 0.5 5.5 IO=24 mA 0.36 0.44 0.5 5.5 VI = VCC or GND ± 0.1 ±1 ±1 µA 5.5 VI = VIH or VIL VO = VCC or GND ± 0.5 ±5 ± 10 µA 5.5 VI = VCC or GND 4 40 80 µA VOLD = 1.65 V max 75 50 mA VOHD = 3.85 V min -75 -50 mA 5.5 V 1) Maximum test duration 2ms, one output loaded at time 2) Incident wave switching is guaranteed on transmission lines with impedances as low as 50Ω 3/9 74AC245 AC ELECTRICAL CHARACTERISTICS (CL = 50 pF, RL = 500 Ω, Input tr = tf = 3ns) Test Condition Symbol Parameter tPLH tPHL Propagation Delay Time tPZL tPZH Output Enable Time tPLZ tPHZ Output Disable Time Value TA = 25°C VCC (V) -40 to 85°C -55 to 125°C Min. Typ. Max. Min. Max. Min. Max. (*) 1.5 5.5 8.5 1.5 9.0 1.5 11.5 (**) 5.0 1.5 4.5 6.5 1.5 7.0 1.5 8.5 3.3(*) 1.5 7.5 12.0 1.5 13.5 1.5 14.0 5.0(**) 1.5 5.5 9.0 1.5 9.5 1.5 10.5 3.3(*) 1.5 6.2 12.0 1.5 13.0 1.5 14.0 (**) 1.5 5.2 9.0 1.5 10.0 1.5 10.5 3.3 5.0 Unit ns ns ns (*) Voltage range is 3.3V ± 0.3V (**) Voltage range is 5.0V ± 0.5V CAPACITIVE CHARACTERISTICS Test Condition Symbol Parameter Value TA = 25°C VCC (V) Min. Typ. Max. -40 to 85°C -55 to 125°C Min. Min. Max. Unit Max. CIN Input Capacitance 5.0 5 pF CI/O I/O Capacitance 5.0 10 pF CPD Power Dissipation Capacitance (note 1) 5.0 21 pF fIN = 10MHz 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 x VCC x fIN + ICC/16 (per circuit) TEST CIRCUIT TEST SWITCH tPLH, tPHL Open tPZL, tPLZ 2VCC tPZH, tPHZ Open CL = 50pF or equivalent (includes jig and probe capacitance) RL = R1 = 500Ω or equivalent RT = ZOUT of pulse generator (typically 50Ω) 4/9 74AC245 WAVEFORM 1: PROPAGATION DELAYS (f=1MHz; 50% duty cycle) WAVEFORM 2: OUTPUT ENABLE AND DISABLE TIME (f=1MHz; 50% duty cycle) 5/9 74AC245 Plastic DIP-20 (0.25) MECHANICAL DATA mm DIM. MIN. a1 0.254 B 1.39 TYP. inch MAX. MIN. TYP. MAX. 0.010 1.65 0.055 0.065 b 0.45 0.018 b1 0.25 0.010 D 25.4 1.000 E 8.5 0.335 e 2.54 0.100 e3 22.86 0.900 F 7.1 0.280 I 3.93 0.155 L Z 3.3 0.130 1.34 0.053 P001J 6/9 74AC245 SO-20 MECHANICAL DATA mm DIM. MIN. TYP. A a1 inch MAX. MIN. TYP. 2.65 0.10 0.104 0.20 a2 MAX. 0.004 0.007 2.45 0.096 b 0.35 0.49 0.013 0.019 b1 0.23 0.32 0.009 0.012 C 0.50 0.020 c1 45 (typ.) D 12.60 13.00 0.496 0.512 E 10.00 10.65 0.393 0.419 e 1.27 0.050 e3 11.43 0.450 F 7.40 7.60 0.291 0.299 L 0.50 1.27 0.19 0.050 M S 0.75 0.029 8 (max.) P013L 7/9 74AC245 TSSOP20 MECHANICAL DATA mm DIM. MIN. inch TYP. MAX. A MIN. TYP. 1.1 0.433 A1 0.05 0.10 0.15 0.002 0.004 0.006 A2 0.85 0.9 0.95 0.335 0.354 0.374 b 0.19 0.30 0.0075 0.0118 c 0.09 0.2 0.0035 0.0079 D 6.4 6.5 6.6 0.252 0.256 0.260 E 6.25 6.4 6.5 0.246 0.252 0.256 E1 4.3 4.4 4.48 0.169 0.173 0.176 e 0.65 BSC 0.0256 BSC K 0o 4o 8o 0o 4o 8o L 0.50 0.60 0.70 0.020 0.024 0.028 A A2 A1 b K e E1 PIN 1 IDENTIFICATION 1 L E c D 8/9 MAX. 74AC245 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 © 2001 STMicroelectronics - Printed in Italy - All Rights Reserved STMicroelectronics GROUP OF COMPANIES Australia - Brazil - China - Finland - France - Germany - Hong Kong - India - Italy - Japan - Malaysia - Malta - Morocco Singapore - Spain - Sweden - Switzerland - United Kingdom © http://www.st.com 9/9