 |
|
| If you can't view the Datasheet, Please click here to try to view without PDF Reader . |
|
|
|
| If you can't view the Datasheet, Please click here to try to view without PDF Reader . |
|
|
| Datasheet File OCR Text: |
| INTEGRATED CIRCUITS 74F148 8-input priority encoder Product specification IC15 Data Handbook 1990 Mar 01 Philips Semiconductors Philips Semiconductors Product specification 8-input priority encoder 74F148 FEATURES * 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 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. PIN CONFIGURATION I4 I5 I6 I7 EI A2 A1 GND 1 2 3 4 5 6 7 8 16 15 14 13 12 11 10 9 VCC EO GS I3 I2 I1 I0 A0 SF00181 TYPE 74F148 TYPICAL PROPAGATION DELAY 6.0ns TYPICAL SUPPLY CURRENT (TOTAL) 23mA ORDERING INFORMATION DESCRIPTION 16-pin plastic DIP 16-pin plastic SO COMMERCIAL RANGE VCC = 5V 10%, Tamb = 0C to +70C N74F148N N74F148D PKG DWG # SOT38-4 SOT109-1 INPUT AND OUTPUT LOADING AND FAN-OUT TABLE PINS I1 - I7 I0 EI EO GS A0 - A2 DESCRIPTION Priority inputs (active Low) Priority input (active Low) Enable input (active Low) Enable output (active Low) Group select output (active Low) Address outputs (active Low) 74F (U.L.) HIGH/LOW 1.0/2.0 1.0/1.0 1.0/2.0 50/33 50/33 50/33 LOAD VALUE HIGH/LOW 20A/1.2mA 20A/0.6mA 20A/1.2mA 1.0mA/20mA 1.0mA/20mA 1.0mA/20mA NOTE: One (1.0) FAST unit load is defined as: 20A 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 12 13 1 2 3 4 IEC/IEEE SYMBOL 10 10/Z10 11 12 I0 I1 I2 I3 I4 I5 I6 I7 13 EO 5 EI GS A0 A1 A2 14 15 1 2 3 4 5 VCC = Pin 16 GND = Pin 8 9 7 6 11/Z11 2/Z12 3/Z13 4/Z14 5/Z15 6/Z16 7/Z17 HPRI/BIN 0 1 2 9 7 8 EN = /V18 10 11 12 13 14 15 16 17 1 18 15 14 SF00182 SF00183 LOGIC DIAGRAM EI 5 I7 4 I6 3 I5 2 I4 1 I3 13 I2 12 I1 11 I0 10 9 VCC = Pin 16 GND = Pin 8 A2 A1 9 A0 9 14 GS 15 EO SF00184 March 1, 1990 3 Philips Semiconductors Product specification 8-input priority encoder 74F148 FUNCTION TABLE INPUTS EI H L L L L L L L L L I0 X H X X X X X X X L I1 X H X X X X X X L H I2 X H X X X X X L H H I3 X H X X X X L H H H I4 X H X X X L H H H H I5 X H X X L H H H H H I6 X H X L H H H H H H I7 X H L H H H H H H H GS H H L L L L L L L L A0 H H L H L H L H L H OUTPUTS A1 H H L L H H L L H H A2 H H L L L L H H H H EO H L H H H H H H H H H = High voltage level L = Low voltage level X = Don't care APPLICATION ENABLE LSB MSB I0 EI EO GS I1 I2 I3 I4 I5 I6 I7 EI EO GS I0 I1 I2 I3 I4 I5 I6 I7 A0 A1 A2 A0 A1 A2 A0 A1 A2 A3 FLAG 16-Input Priority Encoder SF00185 March 1, 1990 4 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 VCC VIN IIN VOUT IOUT Tamb Tstg Supply voltage Input voltage Input current Voltage applied to output in High output state Current applied to output in Low output state Operating free-air temperature range Storage temperature range PARAMETER RATING -0.5 to +7.0 -0.5 to +7.0 -30 to +5 -0.5 to VCC 40 0 to +70 -65 to +150 UNIT V V mA V mA C C RECOMMENDED OPERATING CONDITIONS LIMITS SYMBOL VCC VIH VIL IIK IOH IOL Tamb Supply voltage High-level input voltage Low-level input voltage Input clamp current High-level output current Low-level output current Operating free-air temperature range 0 PARAMETER MIN 4.5 2.0 0.8 -18 -1 20 +70 NOM 5.0 MAX 5.5 V V V mA mA mA C UNIT DC ELECTRICAL CHARACTERISTICS (Over recommended operating free-air temperature range unless otherwise noted.) SYMBOL PARAMETER TEST CONDITIONS1 VCC = MIN, VIL = MAX VIH = MIN, IOH = MAX Low-level Low level output voltage Input clamp voltage Input current at maximum input voltage High-level input current I0 IIL IOS ICC Low-level Low level input current I1 - I7, EI Short-circuit output Supply current current3 VCC = MAX, VI = 0 5V MAX 0.5V VCC = MAX VCC = MAX -60 23 VCC = MIN, VIL = MAX VIH = MIN, IOL = MAX VCC = MIN, II = IIK VCC = MAX, VI = 7.0V VCC = MAX, VI = 2.7V 10%VCC 5%VCC 10%VCC 5%VCC LIMITS MIN 2.5 V 2.7 3.4 0.30 0.30 -0.73 0.50 V 0.50 -1.2 100 20 -0.6 -1.2 -150 35 V A A mA mA mA mA TYP2 MAX UNIT VO OH High-level High level output voltage VO OL VIK II IIH (total)4 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 = 25C. 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 PARAMETER TEST CONDITION VCC = +5.0V Tamb = +25C CL = 50pF, RL = 500 MIN tPLH tPHL tPLH tPHL tPLH tPHL tPLH tPHL tPLH tPHL tPLH tPHL Propagation delay In to An Propagation delay In to EO Propagation delay In to GS Propagation delay EI to An Propagation delay EI to GS Propagation delay EI to EO Waveform 2 Waveform 1 Waveform 2 Waveform 2 Waveform 2 Waveform 2 3.5 3.5 1.5 1.5 2.0 2.0 3.5 3.0 2.5 3.0 3.0 3.5 TYP 6.0 6.0 3.0 2.5 4.0 4.0 6.0 5.5 4.5 5.5 5.0 5.0 MAX 9.0 9.0 6.5 6.5 8.0 8.0 8.5 8.0 7.0 7.5 7.0 7.5 VCC = +5.0V 10% Tamb = 0C to +70C CL = 50pF, RL = 500 MIN 3.5 3.5 1.5 1.5 2.0 2.0 3.5 3.0 2.5 3.0 3.0 3.5 MAX 10.0 10.0 7.5 7.5 9.0 9.0 9.5 9.0 8.0 8.5 8.0 9.0 ns ns ns ns ns ns UNIT AC WAVEFORMS For all waveforms, VM = 1.5V. In, EI VM tPHL VM tPLH In, EI VM tPHL VM tPLH An, EO, GS VM VM An, EO, GS VM VM SF00186 SF00187 Waveform 1. For Inverting Outputs Waveform 2. For Non-Inverting Outputs TEST CIRCUIT AND WAVEFORMS VCC NEGATIVE PULSE VIN PULSE GENERATOR RT D.U.T. VOUT 90% VM 10% tTHL (tf ) CL RL tw VM 10% tTLH (tr ) 0V 90% AMP (V) tTLH (tr ) 90% POSITIVE PULSE VM 10% tw tTHL (tf ) AMP (V) 90% VM 10% 0V Test Circuit for Totem-Pole Outputs 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. Input Pulse Definition INPUT PULSE REQUIREMENTS family amplitude VM 74F 3.0V 1.5V rep. rate 1MHz tw 500ns tTLH 2.5ns tTHL 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) SOT38-4 1990 Mar 01 7 Philips Semiconductors Product specification 8-input priority encoder 74F148 SO16: plastic small outline package; 16 leads; body width 3.9 mm SOT109-1 1990 Mar 01 8 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 Objective specification Preliminary specification Product specification Product status Development Qualification Definition [1] This data sheet contains the design target or goal specifications for product development. Specification may change in any manner without notice. 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. 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. Production [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. Philips Semiconductors 811 East Arques Avenue P.O. Box 3409 Sunnyvale, California 94088-3409 Telephone 800-234-7381 (c) Copyright Philips Electronics North America Corporation 1998 All rights reserved. Printed in U.S.A. print code Document order number: Date of release: 10-98 9397-750-05078 Philips Semiconductors yyyy mmm dd 10 |
Price & Availability of 74F148
 |
|
|
|
|
All Rights Reserved © IC-ON-LINE 2003 - 2022 |
| [Add Bookmark] [Contact Us] [Link exchange] [Privacy policy] |
|
Mirror Sites : [www.datasheet.hk]
[www.maxim4u.com] [www.ic-on-line.cn]
[www.ic-on-line.com] [www.ic-on-line.net]
[www.alldatasheet.com.cn]
[www.gdcy.com]
[www.gdcy.net] |