74AC244 OCTAL BUS BUFFER WITH 3 STATE OUTPUTS (NON INVERTED) ■ ■ ■ ■ ■ ■ ■ ■ ■ HIGH SPEED: tPD = 3.8ns (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 74AC244 is an advanced high-speed CMOS OCTAL BUS BUFFER (3-STATE) fabricated with sub-micron silicon gate and double-layer metal wiring C2MOS tecnology. The G input controls four BUS BUFFERs. ) s ( ct DIP SOP TSSOP ORDER CODES PACKAGE TUBE DIP SOP TSSOP 74AC244B 74AC244M ) s t( T&R o r P c u d 74AC244MTR 74AC244TTR This device is designed to be used with 3 state memory address drivers, etc. All inputs and outputs are equipped with protection circuits against static discharge, giving them 2KV ESD immunity and transient excess voltage. e t le o s b O - u d o r P e PIN CONNECTION AND IEC LOGIC SYMBOLS t e l o s b O April 2001 1/9 74AC244 INPUT AND OUTPUT EQUIVALENT CIRCUIT PIN DESCRIPTION PIN No SYMBOL 1 2, 4, 6, 8 9, 7, 5, 3 11, 13, 15, 17 18, 16, 14, 12 19 10 20 1G 1A1 to 1A4 2Y1 to 2Y4 2A1 to 2A4 Output Enable Input Data Inputs Data Outputs Data Inputs 1Y1 to 1Y4 Data Outputs 2G GND VCC NAME AND FUNCTION Output Enable Input Ground (0V) Positive Supply Voltage TRUTH TABLE INPUTS OUTPUT G An L L H L H X Yn c u d X : Don’t Care Z : High Impedance e t le ABSOLUTE MAXIMUM RATINGS Symbol VCC so Parameter Supply Voltage VI DC Input Voltage VO DC Output Voltage IIK DC Input Diode Current IOK DC Output Diode Current IO DC Output Current ) s ( ct b O - u d o ICC or IGND DC VCC or Ground Current r P e Tstg Storage Temperature TL Lead Temperature (10 sec) o r P L H Z Value ) s t( Unit -0.5 to +7 V -0.5 to VCC + 0.5 V -0.5 to VCC + 0.5 ± 20 mA ± 20 mA ± 50 mA V ± 400 mA -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. t e l o RECOMMENDED OPERATING CONDITIONS s b O Symbol VCC Supply Voltage Value Unit 2 to 6 V VI Input Voltage 0 to VCC V VO Output Voltage 0 to VCC V Top Operating Temperqture 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 Parameter -55 to 125 °C 8 ns/V 74AC244 DC SPECIFICATIONS Test Condition Symbol VIH Parameter 3.0 4.5 5.5 3.0 4.5 5.5 Low Level Input Voltage High Level Output Voltage VOH VOL Low Level Output Voltage II Input Leakage Current High Impedance Output Leakage Current Quiescent Supply Current Ioz ICC IOLD IOHD TA = 25°C VCC (V) High Level Input Voltage VIL Value VO = 0.1 V or VCC-0.1V 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. -55 to 125°C Min. Min. Max. 2.1 3.15 3.85 0.9 1.35 1.65 0.9 1.35 1.65 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 3.0 IO=50 µA 0.002 0.1 0.1 4.5 IO=50 µA 0.001 0.1 0.1 5.5 IO=50 µA 0.001 3.0 IO=12 mA 4.5 IO=24 mA 5.5 IO=24 mA 5.5 VI = VCC or GND 5.5 V c u d V V ) s t( 0.1 0.1 0.36 o r P 0.44 0.5 0.36 0.44 0.5 ± 0.1 ±1 ±1 µA VI = VIH or VIL VO = VCC or GND ± 0.5 ± 2.5 ±5 µA VI = VCC or GND 4 40 80 µA VOLD = 1.65 V max 75 50 mA VOHD = 3.85 V min -75 -50 mA ) s ( ct u d o Max. 0.9 1.35 1.65 IO=-50 µA 5.5 Unit 2.1 3.15 3.85 3.0 5.5 Dynamic Output Current (note 1, 2) Min. -40 to 85°C 0.1 0.36 o s b O - e t le 0.1 0.1 0.44 0.5 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 r P e t e l o s b O 3/9 74AC244 AC ELECTRICAL CHARACTERISTICS (CL = 50 pF, RL = 500 Ω, Input tr = tf = 3ns) Test Condition Symbol Parameter Value TA = 25°C VCC (V) tPLH tPHL Propagation Delay Time tPZL tPZH Output Enable Time tPLZ tPHZ Output Disable Time -40 to 85°C -55 to 125°C Min. Typ. Max. Min. Max. Min. Max. (*) 1.5 5.2 9.0 1.5 10.0 1.5 12.5 (**) 5.0 1.5 3.8 7.0 1.5 7.5 1.5 9.5 3.3(*) 1.5 6.1 10.5 1.5 11.0 1.5 13.0 5.0(**) 1.5 4.2 8.0 1.5 8.5 1.5 10.5 3.3(*) 1.5 6.8 10.5 1.5 11.5 1.5 13.0 (**) 1.5 5.4 9.0 1.5 9.5 1.5 11.0 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 TA = 25°C VCC (V) CIN Input Capacitance COUT Output Capacitance Power Dissipation Capacitance (note 1) CPD Value Min. 5.0 Typ. Max. 4 5.0 8 fIN = 10MHz 5.0 21 e t le -40 to 85°C Min. -55 to 125°C od Max. Pr uc ) s t( Min. Unit Max. pF pF pF o s b O - 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 f IN + ICC/8 (per circuit) TEST CIRCUIT ) s ( ct u d o r P e t e l o s b O 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 74AC244 WAVEFORM 1: PROPAGATION DELAYS (f=1MHz; 50% duty cycle) c u d ) s t( WAVEFORM 2: OUTPUT ENABLE AND DISABLE TIME (f=1MHz; 50% duty cycle) e t le ) s ( ct o r P o s b O - u d o r P e t e l o s b O 5/9 74AC244 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 I 3.93 L c u d e t le 3.3 Z 1.34 ) s ( ct o s b O - o r P ) s t( 0.280 0.155 0.130 0.053 u d o r P e t e l o s b O P001J 6/9 74AC244 SO-20 MECHANICAL DATA mm DIM. MIN. TYP. A inch MAX. MIN. TYP. a1 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 E 10.00 10.65 0.393 0.419 c u d e 1.27 0.050 e3 11.43 0.450 F 7.40 7.60 0.291 L 0.50 1.27 0.19 M e t le 0.75 S 8 (max.) ) s ( ct ) s t( 0.512 o r P 0.299 0.050 0.029 o s b O - u d o r P e t e l o s b O P013L 7/9 74AC244 TSSOP20 MECHANICAL DATA mm DIM. MIN. inch TYP. MAX. A 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 E 6.25 6.4 6.5 0.246 0.252 E1 4.3 4.4 4.48 0.169 0.173 e r P e t le 0.65 BSC o K 0 L 0.50 A o r P e o 4 8 0.60 0.70 ) s ( ct du b e o s b O - o s b O 1 od 0.256 0.176 4o 8o 0.020 0.024 0.028 K L E c E1 PIN 1 IDENTIFICATION uc 0 D t e l o ) s t( 0.260 0.0256 BSC o A2 A1 8/9 MIN. 74AC244 c u d e t le ) s ( ct ) s t( o r P o s b O - u d o r P e t e l o s b O 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