INTEGRATED CIRCUITS DATA SHEET For a complete data sheet, please also download: • The IC06 74HC/HCT/HCU/HCMOS Logic Family Specifications • The IC06 74HC/HCT/HCU/HCMOS Logic Package Information • The IC06 74HC/HCT/HCU/HCMOS Logic Package Outlines 74HC/HCT147 10-to-4 line priority encoder Product specification File under Integrated Circuits, IC06 December 1990 Philips Semiconductors Product specification 10-to-4 line priority encoder 74HC/HCT147 FEATURES GENERAL DESCRIPTION • Encodes 10-line decimal to 4-line BCD The 74HC/HCT147 are high-speed Si-gate CMOS devices and are pin compatible with low power Schottky TTL (LSTTL). They are specified in compliance with JEDEC standard no. 7A. • Useful for 10-position switch encoding • Used in code converters and generators • Output capability: standard The 74HC/HCT147 9-input priority encoders accept data from nine active LOW inputs (A0 to A8) and provide a binary representation on the four active LOW outputs (Y0 to Y3). A priority is assigned to each input so that when two or more inputs are simultaneously active, the input with the highest priority is represented on the output, with input line A8 having the highest priority. • ICC category: MSI The devices provide the 10-line to 4-line priority encoding function by use of the implied decimal “zero”. The “zero” is encoded when all nine data inputs are HIGH, forcing all four outputs HIGH. QUICK REFERENCE DATA GND = 0 V; Tamb = 25 °C; tr = tf = 6 ns TYPICAL SYMBOL PARAMETER CONDITIONS UNIT HC tPHL/ tPLH propagation delay An to Yn CL = 15 pF; VCC = 5 V CI input capacitance CPD power dissipation capacitance per package notes 1 and 2 Notes 1. CPD is used to determine the dynamic power dissipation (PD in µW): PD = CPD × VCC2 × fi + ∑ (CL × VCC2 × fo) where: fi = input frequency in MHz fo = output frequency in MHz ∑ (CL × VCC2 × fo) = sum of outputs CL = output load capacitance in pF VCC = supply voltage in V 2. For HC the condition is VI = GND to VCC For HCT the condition is VI = GND to VCC − 1.5 V ORDERING INFORMATION See “74HC/HCT/HCU/HCMOS Logic Package Information”. December 1990 2 HCT 15 17 ns 3.5 3.5 pF 30 33 pF Philips Semiconductors Product specification 10-to-4 line priority encoder 74HC/HCT147 PIN DESCRIPTION PIN NO. SYMBOL NAME AND FUNCTION 8 GND ground (0 V) 9, 7, 6, 14 Y0 to Y3 BCD address outputs (active LOW) 11, 12, 13, 1, 2, 3, 4, 5, 10 A0 to A8 decimal data inputs (active LOW) 15 n.c. not connected 16 VCC positive supply voltage Fig.1 Pin configuration. Fig.2 Logic symbol. Fig.3 IEC logic symbol. December 1990 3 Philips Semiconductors Product specification 10-to-4 line priority encoder 74HC/HCT147 Fig.4 Functional diagram. FUNCTION TABLE INPUTS A0 A1 A2 A3 OUTPUTS A4 A5 A6 A7 A8 Y3 Y2 Y1 Y0 H H H H H H H H H H H H H X X X X X X X X X X X X X X X X X X X X X X X L X X L H X L H H L H H H L L H H H H L L H H L L L H L H X X X X X X X L X X L H X L H H L H H H H H H H H H H H H H H H H H H H H H H H L L H H H H L L L H L H L H H H H H H H H H H H L Notes 1. H = HIGH voltage level L = LOW voltage level X = don’t care December 1990 4 Philips Semiconductors Product specification 10-to-4 line priority encoder 74HC/HCT147 Fig.5 Logic diagram. December 1990 5 Philips Semiconductors Product specification 10-to-4 line priority encoder 74HC/HCT147 DC CHARACTERISTICS FOR 74HC For the DC characteristics see “74HC/HCT/HCU/HCMOS Logic Family Specifications”. Output capability: standard ICC category: MSI AC CHARACTERISTICS FOR 74HC GND = 0 V; tr = tf = 6 ns; CL = 50 pF Tamb (°C) TEST CONDITIONS 74HC SYMBOL PARAMETER +25 min. typ. −40 to +85 max. min. max. −40 to +125 min. UNIT VCC WAVEFORMS (V) max. tPHL/ tPLH propagation delay An to Yn 50 18 14 160 32 27 200 40 34 240 48 41 ns 2.0 4.5 6.0 Fig.6 tTHL/ tTLH output transition time 19 7 6 75 15 6 95 19 16 110 22 19 ns 2.0 4.5 6.0 Fig.6 December 1990 6 Philips Semiconductors Product specification 10-to-4 line priority encoder 74HC/HCT147 DC CHARACTERISTICS FOR 74HCT For the DC characteristics see “74HC/HCT/HCU/HCMOS Logic Family Specifications”. Output capability: standard ICC category: MSI Note to HCT types The value of additional quiescent supply current (∆ICC) for a unit load of 1 is given in the family specifications. To determine ∆ICC per input, multiply this value by the unit load coefficient shown in the table below. INPUT UNIT LOAD COEFFICIENT A3, A4, A7, A8 1.50 A5, A6, A0, A1, A2 1.10 AC CHARACTERISTICS FOR 74HCT GND = 0 V; tr = tf = 6 ns; CL = 50 pF Tamb (°C) TEST CONDITIONS 74HCT SYMBOL PARAMETER +25 min. typ. −40 to +85 max. min. max. −40 to +125 min. UNIT VCC WAVEFORMS (V) max. tPHL/ tPLH propagation delay An to Yn 20 35 44 53 ns 4.5 Fig.6 tTHL/ tTLH output transition time 7 15 19 22 ns 4.5 Fig.6 AC WAVEFORMS (1) HC : VM = 50%; VI = GND to VCC. HCT: VM = 1.3 V; VI = GND to 3 V. Fig.6 Waveforms showing the decimal data inputs (An) to output (Yn) propagation delays and the output transition times. PACKAGE OUTLINES See “74HC/HCT/HCU/HCMOS Logic Package Outlines”. December 1990 7