M74HC148 8 TO 3 LINE PRIORITY ENCODER ■ ■ ■ ■ ■ ■ ■ HIGH SPEED: tPD = 16ns (TYP.) at VCC = 6V LOW POWER DISSIPATION: ICC = 4µA(MAX.) at TA=25°C HIGH NOISE IMMUNITY: VNIH = V NIL = 28 % VCC (MIN.) SYMMETRICAL OUTPUT IMPEDANCE: |IOH| = IOL = 4mA (MIN) BALANCED PROPAGATION DELAYS: tPLH ≅ tPHL WIDE OPERATING VOLTAGE RANGE: VCC (OPR) = 2V to 6V PIN AND FUNCTION COMPATIBLE WITH 74 SERIES 148 DESCRIPTION The M74HC148 is an high speed CMOS 8 TO 3 LINE PRIORITY ENCODER fabricated with silicon gate C2MOS technology. The M74HC148 encodes eight data lines to three-line (4-2-1) binary (octal). Cascading circuitry (enable input EI and enable output EO) DIP SOP TSSOP ORDER CODES PACKAGE TUBE DIP SOP TSSOP M74HC148B1R M74HC148M1R T&R M74HC148RM13TR M74HC148TTR has been provided to allow octal expansion without the need for external circuitry. Data inputs are active at the low logic level. All inputs are equipped with protection circuits against static discharge and transient excess voltage. PIN CONNECTION AND IEC LOGIC SYMBOLS July 2001 1/11 M74HC148 INPUT AND OUTPUT EQUIVALENT CIRCUIT PIN DESCRIPTION PIN No SYMBOL NAME AND FUNCTION 9, 7, 6 A0 to A2 10, 11, 12, 13, 1, 2, 3, 4 15 5 14 8 16 0 to 7 Data Inputs EO EI GS GND VCC Enable Output Enable Input Priority Flag Output Ground (0V) Positive Supply Voltage Data Outputs TRUTH TABLE INPUTS OUTPUTS E1 0 1 2 3 4 5 6 7 A2 A1 A0 GS E0 H L L L L L L L L L X H X X X X X X X L X H X X X X X X L H X H X X X X X L H H X H X X X X L H H H X H X X X L H H H H X H X X L H H H H H X H X L H H H H H H X H L H H H H H H H H H L L L L H H H H H H L L H H L L H H H H L H L H L H L H H H L L L L L L L L H L H H H H H H H H X : Don’t Care LOGIC DIAGRAM This logic diagram has not be used to estimate propagation delays 2/11 M74HC148 ABSOLUTE MAXIMUM RATINGS Symbol VCC Parameter Value Supply Voltage 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 ± 25 mA ± 50 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 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 Parameter Value Supply Voltage Unit 2 to 6 V VI Input Voltage 0 to VCC V VO Output Voltage 0 to VCC V Top Operating Temperature -55 to 125 °C Input Rise and Fall Time tr, tf VCC = 2.0V 0 to 1000 ns VCC = 4.5V 0 to 500 ns VCC = 6.0V 0 to 400 ns 3/11 M74HC148 DC SPECIFICATIONS Test Condition Symbol VIH VIL VOH VOL II ICC 4/11 Parameter High Level Input Voltage Low Level Input Voltage High Level Output Voltage Low Level Output Voltage Input Leakage Current Quiescent Supply Current Value TA = 25°C VCC (V) Min. 2.0 4.5 6.0 2.0 4.5 6.0 Typ. Max. 1.5 3.15 4.2 -40 to 85°C -55 to 125°C Min. Min. Max. 1.5 3.15 4.2 0.5 1.35 1.8 Max. 1.5 3.15 4.2 0.5 1.35 1.8 V 0.5 1.35 1.8 2.0 IO=-20 µA 1.9 2.0 1.9 1.9 4.5 IO=-20 µA 4.4 4.5 4.4 4.4 6.0 IO=-20 µA 5.9 6.0 5.9 5.9 4.5 IO=-4.0 mA 4.18 4.31 4.13 4.10 5.68 Unit V V 6.0 IO=-5.2 mA 2.0 IO=20 µA 0.0 0.1 0.1 0.1 4.5 IO=20 µA 0.0 0.1 0.1 0.1 6.0 IO=20 µA 0.0 0.1 0.1 0.1 4.5 IO=4.0 mA 0.17 0.26 0.33 0.40 6.0 IO=5.2 mA 0.18 0.26 0.33 0.40 6.0 VI = VCC or GND ± 0.1 ±1 ±1 µA 6.0 VI = VCC or GND 4 40 80 µA 5.8 5.63 5.60 V M74HC148 AC ELECTRICAL CHARACTERISTICS (CL = 50 pF, Input tr = tf = 6ns) Test Condition Symbol Parameter tTLH tTHL Output Transition Time tPLH tPHL Propagation Delay Time (In - A0, A1, A2) tPLH tPHL Propagation Delay Time (In - EO, GS) tPLH tPHL Propagation Delay Time ( EI -EO) tPLH tPHL Propagation Delay Time (EI -GS) tPLH tPHL Propagation Delay Time (EI - A0, A1, A2) Value TA = 25°C VCC (V) Min. 2.0 4.5 6.0 2.0 4.5 6.0 2.0 4.5 6.0 2.0 4.5 6.0 2.0 4.5 6.0 2.0 4.5 6.0 Typ. Max. 30 8 7 60 19 16 60 19 16 40 14 12 40 14 12 40 14 12 75 15 13 150 30 26 150 30 26 115 23 20 115 23 20 115 23 20 -40 to 85°C -55 to 125°C Min. Min. Max. 95 19 16 190 38 32 190 38 32 145 29 25 145 29 25 145 29 25 Unit Max. 110 22 19 225 45 38 225 45 38 175 35 30 175 35 30 175 35 30 ns ns ns ns ns ns CAPACITIVE CHARACTERISTICS Test Condition Symbol Parameter VCC (V) Value TA = 25°C Min. Typ. Max. 10 CIN Input Capacitance 5.0 5 CPD Power Dissipation Capacitance (note 1) 5.0 60 -40 to 85°C -55 to 125°C Min. Min. Max. 10 Unit Max. 10 pF 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) = CPD x VCC x fIN + ICC 5/11 M74HC148 TEST CIRCUIT CL = 50pF or equivalent (includes jig and probe capacitance) RT = ZOUT of pulse generator (typically 50Ω) WAVEFORM 1: PROPAGATION DELAY TIMES ,FOR INVERTING AND NON INVERTING OUTPUTS (f=1MHz; 50% duty cycle) 6/11 M74HC148 TYPICAL APPLICATION 7/11 M74HC148 Plastic DIP-16 (0.25) MECHANICAL DATA mm. inch DIM. MIN. a1 0.51 B 0.77 TYP MAX. MIN. TYP. MAX. 0.020 1.65 0.030 0.065 b 0.5 0.020 b1 0.25 0.010 D 20 0.787 E 8.5 0.335 e 2.54 0.100 e3 17.78 0.700 F 7.1 0.280 I 5.1 0.201 L Z 3.3 0.130 1.27 0.050 P001C 8/11 M74HC148 SO-16 MECHANICAL DATA DIM. mm. MIN. TYP A a1 inch MAX. MIN. TYP. 1.75 0.1 0.068 0.2 a2 MAX. 0.003 0.007 1.65 0.064 b 0.35 0.46 0.013 0.018 b1 0.19 0.25 0.007 0.010 C 0.5 0.019 c1 45° (typ.) D 9.8 10 0.385 0.393 E 5.8 6.2 0.228 0.244 e 1.27 0.050 e3 8.89 0.350 F 3.8 4.0 0.149 0.157 G 4.6 5.3 0.181 0.208 L 0.5 1.27 0.019 0.050 M S 0.62 0.024 8° (max.) PO13H 9/11 M74HC148 TSSOP16 MECHANICAL DATA mm. inch DIM. MIN. TYP A MAX. 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 4.9 5 5.1 0.193 0.197 0.201 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 0.60 0.0256 BSC 8° 0° 0.75 0.018 8° 0.024 0.030 A2 A1 b e K c L E D E1 PIN 1 IDENTIFICATION 1 0080338D 10/11 M74HC148 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. 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