MM54HC148/MM74HC148 8-3 Line Priority Encoder General Description All inputs are protected from damage due to static discharge by internal diode clamps to VCC and ground. This priority encoder utilizes advanced silicon-gate CMOS technology. It has the high noise immunity and low power consumption typical of CMOS circuits, as well as the speeds and output drive similar to LB-TTL. This priority encoder accepts 8 input request lines 0– 7 and outputs 3 lines A0–A2. The priority encoding ensures that only the highest order data line is encoded. Cascading circuitry (enable input EI and enable output EO) has been provided to allow octal expansion without the need for external circuitry. All data inputs and outputs are active at the low logic level. Features Y Y Typical propagation delay: 13 ns Wide supply voltage range: 2V – 6V Connection Diagram Dual-In-Line Package TL/F/9390 – 1 Order Number MM54HC148 or MM74HC148 Truth Table Inputs Outputs EI 0 1 2 3 4 5 6 7 A2 A1 A0 GS EO 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 H e High, L e Low, X e irrelevant C1995 National Semiconductor Corporation TL/F/9390 RRD-B30M105/Printed in U. S. A. MM54HC148/MM74HC148 8-3 Line Priority Encoder February 1988 Absolute Maximum Ratings (Notes 1 & 2) Operation Conditions Min Max Units Supply Voltage (VCC) 2 6 V DC Input or Output Voltage 0 VCC V (VIN, VOUT) Operating Temperature Range (TA) b 40 a 85 MM74HC §C b 55 a 125 MM54HC §C Input Rise or Fall Times (tr, tf) VCC e 2.0V 1000 ns VCC e 4.5V 500 ns VCC e 6.0V 400 ns If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/Distributors for availability and specifications. Supply Voltage (VCC) b 0.5 to a 7.0V DC Input Voltage (VIN) DC Output Voltage (VOUT) Clamp Diode Current (IIK, IOK) DC Output Current, per pin (IOUT) DC VCC or GND Current, per pin (ICC) Storage Temperature Range (TSTG) Power Dissipation (PD) (Note 3) S.O. Package only Lead Temperature (TL) (Soldering 10 sec.) b 1.5 to VCC a 1.5V b 0.5 to VCC a 0.5V g 20 mA g 25 mA g 50 mA b 65§ C to a 150§ C 600 mW 500 mW 260§ C DC Electrical Characteristics (Note 4) Symbol Parameter Conditions VCC TA e 25§ C 74HC TA e b40 to 85§ C Typ 54HC TA e b55 to 125§ C Units Guaranteed Limits VIH Minimum High Level Input Voltage 2.0V 4.5V 6.0V 1.5 3.15 4.2 1.5 3.15 4.2 1.5 3.15 4.2 V V V VIL Maximum Low Level Input Voltage** 2.0V 4.5V 6.0V 0.5 1.35 1.8 0.5 1.35 1.8 0.5 1.35 1.8 V V V VOH Minimum High Level Output Voltage VIN e VIH or VIL lIOUTl s 20 mA 2.0V 4.5V 6.0V 2.0 4.5 6.0 1.9 4.4 5.9 1.9 4.4 5.9 1.9 4.4 5.9 V V V 4.5V 6.0V 4.7 5.2 3.96 5.48 3.84 5.34 3.7 5.2 V V 2.0V 4.5V 6.0V 0 0 0 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 V V V VIN e VIH or VIL lIOUTl s 4.0 mA lIOUTl s 5.2 mA 4.5V 6.0V 0.2 0.2 0.26 0.26 0.33 0.33 0.4 0.4 V V VIN e VIH or VIL lIOUTl s 4.0 mA lIOUTl s 5.2 mA VOL Maximum Low Level Output Voltage VIN e VIH or VIL lIOUTl s 20 mA IIN Maximum Input Current VIN e VCC or GND 6.0V g 0.1 g 1.0 g 1.0 mA ICC Maximum Quiescent Supply Current VIN e VCC or GND IOUT e 0 mA 6.0V 8.0 80 160 mA Note 1: Absolute Maximum Ratings are those values beyond which damage to the device may occur. Note 2: Unless otherwise specified all voltages are referenced to ground. Note 3: Power Dissipation temperature deratingÐplastic ‘‘N’’ package: b 12 mW/§ C from 65§ C to 85§ C, ceramic ‘‘J’’ package: b 12 mW/§ C from 100§ C to 125§ C. Note 4: For a power supply of 5V g 10% the worst case output voltages (VOH, and VOL) occur for HC at 4.5V. Thus the 4.5V values should be used when designing with this supply. Worst case VIH and VIL occur at VCC e 5.5V and 4.5V respectively. (The VIH value at 5.5V is 3.85V.) The worst case leakage current (IIN, ICC, and IOZ) occur for CMOS at the higher voltage and so the 6.0V values should be used. **VIL limits are currently tested at 20% of VCC. The above VIL specification (30% of VCC) will be implemented no later than Q1, CY’89. 2 AC Electrical Characteristics VCC e 5V, TA e 25§ C, CL e 15 pF, tr e tf e 6 ns Symbol Parameter tPHL, tPLH Maximum Propagation Delay, Any Input to Any Output Conditions Typ Units 14 ns AC Electrical Characteristics VCC e 2.0V to 6.0V, CL e 50 pF, tr e tf e 6 ns (unless otherwise specified) Symbol Parameter VCC TA e 25§ C Typ tPHL, tPLH tPHL, tPLH tPHL, tPLH tPHL, tPLH tPHL, tPLH tPHL, tPLH tf, tr 74HC 54HC b 40§ C to a 85§ C b 55§ C to a 125§ C Units Guaranteed Limits Inputs 0–7 to Outputs A0, A1, A2 2.0V 4.5V 6.0V 14 140 28 24 175 35 30 210 42 36 ns ns ns Inputs 0–7 to Output EO 2.0V 4.5V 6.0V 15 140 28 24 175 35 30 210 42 36 ns ns ns Inputs 0–7 to Output GS 2.0V 4.5V 6.0V 17 160 32 27 200 40 34 240 48 41 ns ns ns Input EI to Outputs A0, A1, A2 2.0V 4.5V 6.0V 17 160 32 27 200 40 34 240 48 41 ns ns ns Input EI to Output GS 2.0V 4.5V 6.0V 12 100 20 17 125 25 21 150 30 26 ns ns ns Input EI to Output EO 2.0V 4.5V 6.0V 12 100 20 17 125 25 21 150 30 26 ns ns ns Maximum Output Rise and Fall Time 2.0V 4.5V 6.0V 7 75 15 13 95 19 16 110 22 19 ns ns ns Cpd Power Dissipation Capacitance (Note 5) 52 Cin Maximum Input Capacitance 5 pF 10 10 Note 5: Cpd determines the no load dynamic power consumption, and the no load dynamic current consumption. 3 10 pF 4 HC148 Schematic for Datasheet TL/F/9390 – 3 Logic Diagram TL/F/9390 – 2 Physical Dimensions inches (millimeters) Ceramic Dual-In-Line Package (J) Order Number MM54HC148 or MM74HC148 NS Package Number J16A 5 MM54HC148/MM74HC148 8-3 Line Priority Encoder Physical Dimensions inches (millimeters) (Continued) Molded Dual-In-Line Package (N) Order Number MM54HC148 or MM74HC148 NS Package Number N16E LIFE SUPPORT POLICY NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and whose failure to perform, when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the user. National Semiconductor Corporation 1111 West Bardin Road Arlington, TX 76017 Tel: 1(800) 272-9959 Fax: 1(800) 737-7018 2. A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. National Semiconductor Europe Fax: (a49) 0-180-530 85 86 Email: cnjwge @ tevm2.nsc.com Deutsch Tel: (a49) 0-180-530 85 85 English Tel: (a49) 0-180-532 78 32 Fran3ais Tel: (a49) 0-180-532 93 58 Italiano Tel: (a49) 0-180-534 16 80 National Semiconductor Hong Kong Ltd. 13th Floor, Straight Block, Ocean Centre, 5 Canton Rd. Tsimshatsui, Kowloon Hong Kong Tel: (852) 2737-1600 Fax: (852) 2736-9960 National Semiconductor Japan Ltd. Tel: 81-043-299-2309 Fax: 81-043-299-2408 National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications.