74HCT147N

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 FEATURES • Encodes 10-line decimal to 4-line BCD • Useful for 10-position switch encoding • Used in code converters and generators • Output capability: standard • ICC category: MSI GENERAL DESCRIPTION 74HC/HCT147 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. 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. 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 tPHL/ tPLH CI CPD 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”. PARAMETER propagation delay An to Yn input capacitance power dissipation capacitance per package notes 1 and 2 CONDITIONS HC CL = 15 pF; VCC = 5 V 15 3.5 30 HCT 17 3.5 33 ns pF pF UNIT December 1990 2 Philips Semiconductors Product specification 10-to-4 line priority encoder PIN DESCRIPTION PIN NO. 8 9, 7, 6, 14 11, 12, 13, 1, 2, 3, 4, 5, 10 15 16 SYMBOL NAME AND FUNCTION GND Y0 to Y3 A0 to A8 n.c. VCC ground (0 V) BCD address outputs (active LOW) decimal data inputs (active LOW) not connected positive supply voltage 74HC/HCT147 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 H X X X X X X X X L Notes 1. H = HIGH voltage level L = LOW voltage level X = don’t care H X X X X X X X L H A1 H X X X X X X L H H A2 H X X X X X L H H H A3 H X X X X L H H H H A4 H X X X L H H H H H A5 H X X L H H H H H H A6 H X L H H H H H H H A7 H L H H H H H H H H A8 H L L H H H H H H H Y3 H H H L L L L H H H OUTPUTS Y2 H H H L L H H L L H Y1 H L H L H L H L H L Y0 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 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) 74HC SYMBOL PARAMETER min. tPHL/ tPLH propagation delay An to Yn output transition time +25 typ. 50 18 14 19 7 6 max. 160 32 27 75 15 6 −40 to +85 min. max. 200 40 34 95 19 16 −40 to +125 min. max. 240 48 41 110 22 19 ns UNIT 74HC/HCT147 TEST CONDITIONS VCC WAVEFORMS (V) 2.0 4.5 6.0 2.0 4.5 6.0 Fig.6 tTHL/ tTLH ns Fig.6 December 1990 6 Philips Semiconductors Product specification 10-to-4 line priority encoder 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 74HC/HCT147 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 A3, A4, A7, A8 A5, A6, A0, A1, A2 UNIT LOAD COEFFICIENT 1.50 1.10 AC CHARACTERISTICS FOR 74HCT GND = 0 V; tr = tf = 6 ns; CL = 50 pF Tamb (°C) 74HCT SYMBOL PARAMETER min. tPHL/ tPLH tTHL/ tTLH propagation delay An to Yn output transition time +25 typ. 20 7 max. 35 15 −40 to +85 min. max. 44 19 −40 to +125 min. max. 53 22 ns ns 4.5 4.5 Fig.6 Fig.6 UNIT VCC WAVEFORMS (V) TEST CONDITIONS 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