INTEGRATED CIRCUITS 74F148 8-input priority encoder Product specification IC15 Data Handbook 1990 Mar 01 Philips Semiconductors Product specification 8-input priority encoder 74F148 FEATURES PIN CONFIGURATION • Code conversions • Multi-channel D/A converter • Decimal-to-BCD converter • Cascading for priority encoding of “N” bits • Input enable capability • Priority encoding-automatic selection of highest priority input line • Output enable-active Low when all inputs are High • Group signal output-active when any input is Low I4 1 16 VCC I5 2 15 EO I6 3 14 GS I7 4 13 I3 EI 5 12 I2 A2 6 11 I1 A1 7 10 I0 GND 8 9 A0 SF00181 DESCRIPTION The 74F148 8-input priority encoder accepts data from eight active-Low inputs and provides a binary representation on the three active-Low outputs. 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 I7 having the highest priority. A High on the Enable Input (EI) will force all outputs to the inactive (High) state and allow new data to settle without producing erroneous information at the outputs. A Group Signal (GS) output and an Enable Output (EO) are provided with the three data outputs. The GS is active-Low when any input is Low: this indicates when any input is active. The EO is active-Low when all inputs are High. Using the Enable Output along with the Enable Input allows priority encoding of N input signals. Both EO and GS are active-High when the Enable Input is High. TYPE TYPICAL PROPAGATION DELAY TYPICAL SUPPLY CURRENT (TOTAL) 74F148 6.0ns 23mA ORDERING INFORMATION DESCRIPTION COMMERCIAL RANGE VCC = 5V ±10%, Tamb = 0°C to +70°C PKG DWG # 16-pin plastic DIP N74F148N SOT38-4 16-pin plastic SO N74F148D SOT109-1 INPUT AND OUTPUT LOADING AND FAN-OUT TABLE PINS DESCRIPTION 74F (U.L.) HIGH/LOW LOAD VALUE HIGH/LOW I1 – I7 Priority inputs (active Low) 1.0/2.0 20µA/1.2mA I0 Priority input (active Low) 1.0/1.0 20µA/0.6mA EI Enable input (active Low) 1.0/2.0 20µA/1.2mA EO Enable output (active Low) 50/33 1.0mA/20mA GS Group select output (active Low) 50/33 1.0mA/20mA Address outputs (active Low) 50/33 1.0mA/20mA A0 – A2 NOTE: One (1.0) FAST unit load is defined as: 20µA in the High state and 0.6mA in the Low state. March 1, 1990 2 853–0345 98994 Philips Semiconductors Product specification 8-input priority encoder 74F148 LOGIC SYMBOL 10 11 IEC/IEEE SYMBOL 12 13 1 2 3 4 10 10/Z10 11 I1 I2 I3 I4 I5 I6 13 5 EO 15 GS 14 4/Z14 2 A1 A2 6/Z16 4 7/Z17 5 VCC = Pin 16 GND = Pin 8 9 7 10 11 12 13 14 15 16 17 5/Z15 3 A0 EN = α/V18 6 SF00182 I6 I7 4 5 I5 3 I4 2 9 VCC = Pin 16 GND = Pin 8 A2 I3 1 I2 13 9 9 A1 I1 12 A0 I0 11 14 GS 10 15 EO SF00184 March 1, 1990 7 8 ≥1 18 α 15 14 SF00183 LOGIC DIAGRAM EI 9 3/Z13 1 EI 2α 2/Z12 I7 0α 1α 11/Z11 12 I0 HPRI/BIN 3 Philips Semiconductors Product specification 8-input priority encoder 74F148 FUNCTION TABLE INPUTS OUTPUTS EI I0 I1 I2 I3 I4 I5 I6 I7 GS A0 A1 A2 EO H X X X X X X X X H H H H H L H H H H H H H H H H H H L L X X X X X X X L L L L L H L X X X X X X L H L H L L H L X X X X X L H H L L H L H L X X X X L H H H L H H L H L X X X L H H H H L L L H H L X X L H H H H H L H L H H L X L H H H H H H L L H H H L L H H H H H H H L H H H H H = High voltage level L = Low voltage level X = Don’t care APPLICATION ENABLE LSB I0 MSB I1 I2 I3 I4 I5 I6 I7 I0 EI EI EO EO GS I2 I3 I4 I5 I6 I7 GS A0 A0 A1 A2 A1 A0 A2 A3 A1 A2 FLAG 16-Input Priority Encoder March 1, 1990 I1 4 SF00185 Philips Semiconductors Product specification 8-input priority encoder 74F148 ABSOLUTE MAXIMUM RATINGS (Operation beyond the limits set forth in this table may impair the useful life of the device. Unless otherwise noted these limits are over the operating free-air temperature range.) SYMBOL PARAMETER RATING UNIT VCC Supply voltage –0.5 to +7.0 V VIN Input voltage –0.5 to +7.0 V IIN Input current –30 to +5 mA VOUT Voltage applied to output in High output state –0.5 to VCC V IOUT Current applied to output in Low output state Tamb Operating free-air temperature range Tstg Storage temperature range 40 mA 0 to +70 °C –65 to +150 °C RECOMMENDED OPERATING CONDITIONS LIMITS SYMBOL PARAMETER UNIT MIN NOM MAX 5.0 5.5 VCC Supply voltage 4.5 V VIH High-level input voltage 2.0 VIL Low-level input voltage 0.8 V IIK Input clamp current –18 mA IOH High-level output current –1 mA IOL Low-level output current 20 mA Tamb Operating free-air temperature range +70 °C V 0 DC ELECTRICAL CHARACTERISTICS (Over recommended operating free-air temperature range unless otherwise noted.) SYMBOL TEST CONDITIONS1 PARAMETER LIMITS MIN TYP2 ±10%VCC 2.5 VIH = MIN, IOH = MAX ±5%VCC 2.7 VCC = MIN, VIL = MAX ±10%VCC 0.30 0.50 VIH = MIN, IOL = MAX ±5%VCC 0.30 0.50 –0.73 –1.2 V 100 µA High level output voltage High-level VOL O Low level output voltage Low-level VIK Input clamp voltage VCC = MIN, II = IIK II Input current at maximum input voltage VCC = MAX, VI = 7.0V IIH High-level input current VCC = MAX, VI = 2.7V V 3.4 V I0 IOS ICC Low level input current Low-level I1 – I7, EI Short-circuit output Supply current current3 (total)4 UNIT VCC = MIN, VIL = MAX VOH O IIL MAX VCC = MAX, MAX VI = 0 0.5V 5V VCC = MAX VCC = MAX –60 23 20 µA –0.6 mA –1.2 mA –150 mA 35 mA NOTES: 1. For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions for the applicable type. 2. All typical values are at VCC = 5V, Tamb = 25°C. 3. Not more than one output should be shorted at a time. For testing IOS, the use of high-speed test apparatus and/or sample-and-hold techniques are preferable in order to minimize internal heating and more accurately reflect operational values. Otherwise, prolonged shorting of a High output may raise the chip temperature well above normal and thereby cause invalid readings in other parameter tests. In any sequence of parameter tests, IOS tests should be performed last. 4. To measure ICC, outputs must be open, VIN on all inputs = 4.5V. March 1, 1990 5 Philips Semiconductors Product specification 8-input priority encoder 74F148 AC ELECTRICAL CHARACTERISTICS LIMITS SYMBOL VCC = +5.0V ± 10% Tamb = 0°C to +70°C CL = 50pF, RL = 500Ω VCC = +5.0V Tamb = +25°C CL = 50pF, RL = 500Ω TEST CONDITION PARAMETER MIN TYP MAX MIN MAX UNIT tPLH tPHL Propagation delay In to An Waveform 2 3.5 3.5 6.0 6.0 9.0 9.0 3.5 3.5 10.0 10.0 ns tPLH tPHL Propagation delay In to EO Waveform 1 1.5 1.5 3.0 2.5 6.5 6.5 1.5 1.5 7.5 7.5 ns tPLH tPHL Propagation delay In to GS Waveform 2 2.0 2.0 4.0 4.0 8.0 8.0 2.0 2.0 9.0 9.0 ns tPLH tPHL Propagation delay EI to An Waveform 2 3.5 3.0 6.0 5.5 8.5 8.0 3.5 3.0 9.5 9.0 ns tPLH tPHL Propagation delay EI to GS Waveform 2 2.5 3.0 4.5 5.5 7.0 7.5 2.5 3.0 8.0 8.5 ns tPLH tPHL Propagation delay EI to EO Waveform 2 3.0 3.5 5.0 5.0 7.0 7.5 3.0 3.5 8.0 9.0 ns AC WAVEFORMS For all waveforms, VM = 1.5V. In, EI VM tPHL tPLH VM An, EO, GS VM In, EI VM VM tPHL VM tPLH VM An, EO, GS VM SF00186 SF00187 Waveform 1. For Inverting Outputs Waveform 2. For Non-Inverting Outputs TEST CIRCUIT AND WAVEFORMS VCC NEGATIVE PULSE VIN tw 90% VM D.U.T. RT CL RL AMP (V) VM 10% VOUT PULSE GENERATOR 90% 10% tTHL (tf ) tTLH (tr ) tTLH (tr ) tTHL (tf ) 0V AMP (V) 90% 90% POSITIVE PULSE DEFINITIONS: RL = Load resistor; see AC ELECTRICAL CHARACTERISTICS for value. CL = Load capacitance includes jig and probe capacitance; see AC ELECTRICAL CHARACTERISTICS for value. RT = Termination resistance should be equal to ZOUT of pulse generators. VM VM 10% Test Circuit for Totem-Pole Outputs 10% tw 0V Input Pulse Definition INPUT PULSE REQUIREMENTS family amplitude VM 74F 3.0V 1.5V rep. rate 1MHz tw tTLH tTHL 500ns 2.5ns 2.5ns SF00006 March 1, 1990 6 Philips Semiconductors Product specification 8-input priority encoder 74F148 DIP16: plastic dual in-line package; 16 leads (300 mil) 1990 Mar 01 7 SOT38-4 Philips Semiconductors Product specification 8-input priority encoder 74F148 SO16: plastic small outline package; 16 leads; body width 3.9 mm 1990 Mar 01 8 SOT109-1 Philips Semiconductors Product specification 8-input priority encoder 74F148 NOTES 1990 Mar 01 9 Philips Semiconductors Product specification 8-input priority encoder 74F148 Data sheet status Data sheet status Product status Definition [1] Objective specification Development This data sheet contains the design target or goal specifications for product development. Specification may change in any manner without notice. Preliminary specification Qualification This data sheet contains preliminary data, and supplementary data will be published at a later date. Philips Semiconductors reserves the right to make chages at any time without notice in order to improve design and supply the best possible product. Product specification Production This data sheet contains final specifications. Philips Semiconductors reserves the right to make changes at any time without notice in order to improve design and supply the best possible product. [1] Please consult the most recently issued datasheet before initiating or completing a design. Definitions Short-form specification — The data in a short-form specification is extracted from a full data sheet with the same type number and title. For detailed information see the relevant data sheet or data handbook. Limiting values definition — Limiting values given are in accordance with the Absolute Maximum Rating System (IEC 134). Stress above one or more of the limiting values may cause permanent damage to the device. These are stress ratings only and operation of the device at these or at any other conditions above those given in the Characteristics sections of the specification is not implied. Exposure to limiting values for extended periods may affect device reliability. Application information — Applications that are described herein for any of these products are for illustrative purposes only. Philips Semiconductors make no representation or warranty that such applications will be suitable for the specified use without further testing or modification. Disclaimers Life support — These products are not designed for use in life support appliances, devices or systems where malfunction of these products can reasonably be expected to result in personal injury. Philips Semiconductors customers using or selling these products for use in such applications do so at their own risk and agree to fully indemnify Philips Semiconductors for any damages resulting from such application. Right to make changes — Philips Semiconductors reserves the right to make changes, without notice, in the products, including circuits, standard cells, and/or software, described or contained herein in order to improve design and/or performance. Philips Semiconductors assumes no responsibility or liability for the use of any of these products, conveys no license or title under any patent, copyright, or mask work right to these products, and makes no representations or warranties that these products are free from patent, copyright, or mask work right infringement, unless otherwise specified. Copyright Philips Electronics North America Corporation 1998 All rights reserved. Printed in U.S.A. Philips Semiconductors 811 East Arques Avenue P.O. Box 3409 Sunnyvale, California 94088–3409 Telephone 800-234-7381 print code Document order number: yyyy mmm dd 10 Date of release: 10-98 9397-750-05078