M74HCT245 OCTAL BUS TRANSCEIVER WITH 3 STATE OUTPUTS (NON INVERTED) ■ ■ ■ ■ ■ ■ HIGH SPEED: tPD = 13ns (TYP.) at VCC = 4.5V LOW POWER DISSIPATION: ICC = 4µA(MAX.) at TA=25°C COMPATIBLE WITH TTL OUTPUTS : VIH = 2V (MIN.) VIL = 0.8V (MAX) SYMMETRICAL OUTPUT IMPEDANCE: |IOH| = IOL = 6mA (MIN) BALANCED PROPAGATION DELAYS: tPLH ≅ tPHL PIN AND FUNCTION COMPATIBLE WITH 74 SERIES 245 DESCRIPTION The M74HCT245 is an advanced high-speed CMOS OCTAL BUS TRANSCEIVER (3-STATE) fabricated with silicon gate C2MOS technology. This IC is intended for two-way asynchronous communication between data buses, and the direction of data transmission is determined by DIR input. The enable input G can be used to disable the device so that the buses are effectively isolated. DIP SOP TSSOP ORDER CODES PACKAGE TUBE DIP SOP TSSOP M74HCT245B1R M74HCT245M1R T&R M74HCT245RM13TR M74HCT245TTR All inputs are equipped with protection circuits against static discharge and transient excess voltage. All floating bus terminals during High Z State must be held HIGH or LOW. PIN CONNECTION AND IEC LOGIC SYMBOLS August 2001 1/9 M74HCT245 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 -0.5 to VCC + 0.5 -0.5 to VCC + 0.5 V DC Input Diode Current ± 20 mA IOK DC Output Diode Current ± 20 mA IO DC Output Current ± 35 mA VI DC Input Voltage VO DC Output Voltage IIK ICC or IGND DC VCC or Ground Current PD Power Dissipation Tstg Storage Temperature TL Lead Temperature (10 sec) V ± 70 mA 500(*) mW -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 (*) 500mW at 65 °C; derate to 300mW by 10mW/ °C from 65°C to 85°C RECOMMENDED OPERATING CONDITIONS Symbol VCC 2/9 Parameter Value Unit Supply Voltage 4.5 to 5.5 V VI Input Voltage 0 to VCC V VO Output Voltage Top Operating Temperature tr, tf Input Rise and Fall Time (VCC = 4.5 to 5.5V) 0 to VCC V -55 to 125 °C 0 to 500 ns M74HCT245 DC SPECIFICATIONS Test Condition Symbol VIH VIL VOH VOL II IOZ ICC ∆ ICC Parameter High Level Input Voltage Low Level Input Voltage Min. 4.5 to 5.5 4.5 to 5.5 4.5 Low Level Output Voltage 4.5 Input Leakage Current High Impedance Output Leakage Current Quiescent Supply Current Additional Worst Case Supply Current TA = 25°C VCC (V) High Level Output Voltage Value Typ. Max. 2.0 -40 to 85°C -55 to 125°C Min. Min. Max. 2.0 0.8 Max. 2.0 0.8 V 0.8 IO=-20 µA 4.4 4.5 4.4 4.4 IO=-6.0 mA 4.18 4.31 4.13 4.10 Unit V V IO=20 µA 0.0 0.1 0.1 0.1 IO=6.0 mA 0.17 0.26 0.33 0.40 V 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 5.5 Per Input pin VI = 0.5V or VI = 2.4V Other Inputs at VCC or GND IO = 0 2.0 2.9 3.0 mA AC ELECTRICAL CHARACTERISTICS (CL = 50 pF, Input tr = tf = 6ns) Test Condition Symbol Parameter tTLH tTHL Output Transition Time tPLH tPHL Propagation Delay Time tPZL tPZH High Impedance Output Enable Time tPLZ tPHZ High Impedance Output Disable Time VCC (V) CL (pF) 4.5 4.5 4.5 4.5 Value TA = 25°C Min. -40 to 85°C -55 to 125°C Min. Min. Max. Unit Typ. Max. Max. 50 7 12 15 18 ns 50 150 13 18 22 30 28 38 33 45 ns 50 RL = 1 KΩ 19 30 38 45 150 RL = 1 KΩ 24 38 48 57 50 RL = 1 KΩ 17 30 38 45 ns ns 3/9 M74HCT245 CAPACITIVE CHARACTERISTICS Test Condition Symbol Parameter CIN Input Capacitance CI/OUT Output Capacitance Power Dissipation Capacitance (note 1) CPD Value TA = 25°C VCC (V) Min. -40 to 85°C -55 to 125°C Min. Min. Max. Unit Typ. Max. Max. DIR, G 5 10 An, Bn 13 pF 41 pF 10 10 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) = C PD x VCC x fIN + ICC/8 (per circuit) TEST CIRCUIT TEST SWITCH tPLH, tPHL Open tPZL, tPLZ VCC tPZH, tPHZ GND CL = 50pF/150pF or equivalent (includes jig and probe capacitance) R1 = 1KΩ or equivalent RT = ZOUT of pulse generator (typically 50Ω) 4/9 M74HCT245 WAVEFORM 1 : PROPAGATION DELAY TIME (f=1MHz; 50% duty cycle) WAVEFORM 2 : OUTPUT ENABLE AND DISABLE TIME (f=1MHz; 50% duty cycle) 5/9 M74HCT245 Plastic DIP-20 (0.25) MECHANICAL DATA mm. inch DIM. MIN. a1 0.254 B 1.39 TYP 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 M74HCT245 SO-20 MECHANICAL DATA mm. inch DIM. MIN. TYP A a1 MAX. MIN. TYP. 2.65 0.1 0.104 0.2 a2 MAX. 0.004 0.008 2.45 0.096 b 0.35 0.49 0.014 0.019 b1 0.23 0.32 0.009 0.012 C 0.5 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 0.300 L 0.50 1.27 0.020 0.050 M S 0.75 0.029 8° (max.) PO13L 7/9 M74HCT245 TSSOP20 MECHANICAL DATA mm. inch DIM. MIN. TYP MAX. A MIN. TYP. MAX. 1.2 A1 0.05 A2 0.8 b 0.047 0.15 0.002 0.004 0.006 1.05 0.031 0.039 0.041 0.19 0.30 0.007 0.012 c 0.09 0.20 0.004 0.0089 D 6.4 6.5 6.6 0.252 0.256 0.260 E 6.2 6.4 6.6 0.244 0.252 0.260 E1 4.3 4.4 4.48 0.169 0.173 0.176 1 e 0.65 BSC K 0° L 0.45 A 0.0256 BSC 0.60 8° 0° 0.75 0.018 8° 0.024 0.030 A2 A1 b K e L E c D E1 PIN 1 IDENTIFICATION 1 0087225C 8/9 M74HCT245 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