74VHC245 OCTAL BUS TRANSCEIVER (3-STATE) PRELIMINARY DATA ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ HIGH SPEED: tPD = 4.0 ns (TYP.) at VCC = 5V LOW POWER DISSIPATION: ICC = 4 µA (MAX.) at TA = 25 oC HIGH NOISE IMMUNITY: VNIH = VNIL = 28% VCC (MIN.) POWER DOWN PROTECTION ON CONTROL INPUTS SYMMETRICAL OUTPUT IMPEDANCE: |IOH| = IOL = 8 mA (MIN) BALANCED PROPAGATION DELAYS: tPLH ≅ tPHL OPERATING VOLTAGE RANGE: VCC (OPR) = 2V to 5.5V PIN AND FUNCTION COMPATIBLE WITH 74 SERIES 245 IMPROVED LATCH-UP IMMUNITY LOW NOISE VOLP = 0.9V (Max.) DESCRIPTION The 74VHC245 is an advanced high-speed CMOS OCTAL BUS TRANSCEIVER (3-STATE) fabricated with sub-micron silicon gate and double-layer metal wiring C2MOS technology. This IC is intended for two-way asynchronous communication between data busses; the direction of data trasmission is determined by the level of the DIR input. The enable input G can be M (Micro Package) T (TSSOP Package) ORDER CODES : 74VHC245M 74VHC245T 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. IT IS PROHIBITED TO APPLY A SIGNAL TO A TERMINAL WHEN IT IS IN OUTPUT MODE AND WHEN A BUS TERMINAL IS FLOATING (HIGH IMPEDANCE STATE) IT IS REQUESTED TO FIX THE INPUT LEVEL BY MEANS OF EXTERNAL PULL DOWN OR PULL UP RESISTOR. PIN CONNECTION AND IEC LOGIC SYMBOLS June 1999 1/8 74VHC245 INPUT EQUIVALENT CIRCUIT PIN DESCRIPTION PIN No SYMBOL 1 DIR NAME AND FUNCT ION 2, 3, 4, 5, 6, 7, 8, 9 A1 to A8 Data Inputs/Outputs 18, 17, 16, 15, 14, 13, 12, 11 B1 to B8 Data Inputs/Outputs 19 G Output Enable Input 10 GND Ground (0V) 20 VCC Positive Supply Voltage Directional Control TRUTH TABLE INPUT G F UNCTION OUT PUT DIR A BUS B BUS L L OUTPUT INPUT A=B L H INPUT OUTPUT B=A H X Z Z Z X:”H” or ”L” Z: High impedance ABSOLUTE MAXIMUM RATINGS Symbol VCC Parameter Supply Voltage Unit V -0.5 to +7.0 V VI/O Bus I/O 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 ± 25 mA ± 75 mA VI DC Input Voltage (DIR, G) Value -0.5 to +7.0 ICC or IGND DC VCC or Ground Current Tstg TL Storage Temperature Lead Temperature (10 sec) -65 to +150 o 300 o C 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 VI Parameter Supply Voltage Input Voltage (DIR, G) V V V Bus I/O Voltage 0 to VCC VO Output Voltage 0 to VCC Top Operating Temperature Input Rise and Fall Time (see note 1) (VCC = 3.3 ± 0.3V) (V CC = 5.0 ± 0.5V) 1) VIN from 30% to70%of VCC Unit 0 to 5.5 VI/O dt/dv 2/8 Valu e 2.0 to 5.5 -40 to +85 0 to 100 0 to 20 V o C ns/V ns/V 74VHC245 DC SPECIFICATIONS Symb ol VIH VIL VOH VOL Parameter T est Cond ition s Min. II ICC Typ . Un it -40 to 85 o C Max. Min . Max. High Level Input Voltage 2.0 1.5 1.5 3.0 to 5.5 0.7VCC 0.7VCC Low Level Input Voltage 2.0 0.5 0.5 3.0 to 5.5 0.3VCC 0.3VCC High Level Output Voltage Low Level Output Voltage High Impedance Output Leakage Current Input Leakage Current Quiescent Supply Current V 2.0 I O =-50 µA 1.9 2.0 1.9 3.0 IO=-50 µA IO=-50 µA 2.9 3.0 2.9 4.5 4.4 4.5 4.4 3.0 IO=-4 mA 2.58 2.48 4.5 IO=-8 mA 3.94 3.8 2.0 I O=50 µA 0.0 0.1 0.1 3.0 IO=50 µA IO=50 µA 0.0 0.1 0.1 0.0 0.1 0.1 0.44 4.5 IOZ Value T A = 25 o C V CC (V) V V V 3.0 IO=4 mA 0.36 4.5 IO=8 mA 0.36 0.44 ±0.25 ±2.5 µA 5.5 VI = VIH or VIL VO = VCC or GND 0 to 5.5 VI = 5.5V or GND ±0.1 ±1.0 µA 5.5 VI = VCC or GND 4 40 µA AC ELECTRICAL CHARACTERISTICS (Input t r = tf =3 ns) Symb ol Parameter V CC (V) tPLH tPHL Propagation Delay Time tPLZ tPHZ Output Disable Time tPZL tPZH Output Enable Time tOSLH tOSHL Output to Output Skew Time (note 1) Test Co ndition CL (pF ) 3.3(*) 3.3(*) 5.0(**) 15 50 15 5.0 3.3(*) (**) 50 15 3.3(*) 5.0(**) 5.0(**) 3.3(*) 5.0(**) 3.3(*) 5.0(**) 50 15 50 50 50 50 Value T A = 25 o C Typ . 5.8 8.3 4.0 Max. 8.4 11.9 5.5 Min . 1.0 1.0 1.0 Max. 10.0 13.5 6.5 RL = 1KΩ 5.5 8.5 7.5 13.2 1.0 1.0 8.5 15.5 RL = RL = RL = RL = RL = 11.0 5.8 7.3 11.5 7.0 16.7 8.5 10.6 15.8 9.7 1.5 1.0 1.0 1.0 1.0 1.0 1.0 19.0 10.0 12.0 18.0 11.0 1.5 1.0 50 Min. Un it -40 to 85 o C 1KΩ 1KΩ 1KΩ 1KΩ 1KΩ ns ns ns ns (*) Voltage range is 3.3V ± 0.3V (**) Voltage range is 5V ± 0.5V Note 1: Parameter guaranteed by design. tsoLH = |tpLHm- tpLHn|, tsoHL = |tpHLm - tpHLn| 3/8 74VHC245 CAPACITIVE CHARACTERISTICS Symb ol Parameter Test Co nditions Valu e T A = 25 oC Min. Un it -40 to 85 o C T yp. Max. C IN Input Capacitance 4 10 Min. Max. CI/O Bus Input Capacitance 8 pF CPD Power Dissipation Capacitance (note 1) 21 pF 10 pF 1) CPD isdefined as the value of the IC’sinternal equivalent capacitance which is calculated fromthe operating current consumption without load. (Referto Test Circuit).Average operting current can be obtained by the following equation. ICC(opr) = CPD • VCC • fIN + ICC/8(per circuit) DYNAMIC SWITCHING CHARACTERISTICS Symb ol Parameter T est Cond ition s Dynamic Low Voltage Quiet Output (note 1, 2) 5.0 VIHD Dynamic High Voltage Input (note 1, 3) 5.0 VILD Dynamic Low Voltage Input (note 1, 3) 5.0 VOLP VOLV Value T A = 25 o C V CC (V) Min. -0.9 C L = 50 pF Un it -40 to 85 o C Typ . Max. 0.6 0.9 Min . Max. -0.6 3.5 V 1.5 1) Worst case package. 2) Max number of outputs defined as (n). Data inputs are driven 0V to 5.0V, (n -1) outputs switching and one output at GND. 3) Max number of data inputs (n) switching. (n-1) switching 0V to5.0V. Inputs under test switching: 5.0V to threshold (VILD), 0V to threshold (VIHD), f=1MHz. TEST CIRCUIT T EST tPLH , tPHL SW IT CH Open tPZL , tPLZ VCC tPZH , tPHZ GND CL = 15/50 pF or equivalent (includes jig and probe capacitance) RL = R1 = 1KΩ orequivalent RT = ZOUT of pulse generator (typically 50Ω) 4/8 74VHC245 WAVEFORM 1: PROPAGATION DELAYS (f=1MHz; 50% duty cycle) WAVEFORM 2: OUTPUT ENABLE AND DISABLE TIME (f=1MHz; 50% duty cycle) 5/8 74VHC245 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 6/8 74VHC245 TSSOP20 MECHANICAL DATA mm DIM. MIN. inch TYP. MAX. A MIN. TYP. MAX. 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 L E c D E1 PIN 1 IDENTIFICATION 1 7/8 74VHC245 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. Specification 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 trademark of STMicroelectronics 1999 STMicroelectronics – Printed in Italy – All Rights Reserved STMicroelectronics GROUP OF COMPANIES Australia - Brazil - Canada - China - France - Germany - Italy - Japan - Korea - Malaysia - Malta - Mexico - Morocco - The Netherlands Singapore - Spain - Sweden - Switzerland - Taiwan - Thailand - United Kingdom - U.S.A. http://www.st.com . 8/8