SN74AS280NSR


 

  

 SDAS038C − DECEMBER 1982 − REVISED DECEMBER 1994 • • • • D OR N PACKAGE (TOP VIEW) Generate Either Odd or Even Parity for Nine Data Lines Cascadable for n-Bit Parity Can Be Used to Upgrade Existing Systems Using MSI Parity Circuits Package Options Include Plastic Small-Outline (D) Packages and Standard Plastic (N) 300-mil DIPs G H NC I Σ EVEN Σ ODD GND description 1 14 2 13 3 12 4 11 5 10 6 9 7 8 VCC F E D C B A NC − No internal connection These universal 9-bit parity generators/checkers utilize advanced Schottky high-performance circuitry and feature odd (Σ ODD) and even (Σ EVEN) outputs to facilitate operation of either odd- or even-parity applications. The word-length capability is easily expanded by cascading. These devices can be used to upgrade the performance of most systems utilizing the SN74ALS180 and SN74AS180 parity generators/checkers. Although the SN74ALS280 and SN74AS280 are implemented without expander inputs, the corresponding function is provided by the availability of an input (I) at terminal 4 and the absence of any internal connection at terminal 3. This permits the SN74ALS280 and SN74AS280 to be substituted for the SN74ALS180 and SN74AS180 in existing designs to produce an identical function even if the devices are mixed with existing SN74ALS180 and SN74AS180 devices. All SN74AS280 inputs are buffered to lower the drive requirements. The SN74ALS280 and SN74AS280 are characterized for operation from 0°C to 70°C. FUNCTION TABLE NO. OF INPUTS A −I THAT ARE HIGH Σ EVEN 0, 2, 4, 6, 8 H L 1, 3, 5, 7, 9 L H OUTPUTS Σ ODD logic symbol† A B C D E F G H I 2k 8 9 10 5 11 Σ EVEN 12 13 6 1 Σ ODD 2 4 † This symbol is in accordance with ANSI/IEEE Std 91-1984 and IEC Publication 617-12. Copyright  1994, Texas Instruments Incorporated   !"#$%&" ' ()##*& %' "! +),-(%&" .%&*/ #".)(&' ("!"#$ &" '+*(!(%&"' +*# &0* &*#$' "! *1%' '&#)$*&' '&%.%#. 2%##%&3/ #".)(&" +#"(*''4 ."*' "& *(*''%#-3 (-).* &*'&4 "! %-- +%#%$*&*#'/ • DALLAS, TEXAS 75265 • HOUSTON, TEXAS 77251−1443 POST OFFICE BOX 655303 POST OFFICE BOX 1443 1 

 

  

 SDAS038C − DECEMBER 1982 − REVISED DECEMBER 1994 logic diagram (positive logic) A B C 8 9 10 5 D E F 11 12 13 6 G H I Σ EVEN Σ ODD 1 2 4 absolute maximum ratings over operating free-air temperature range (unless otherwise noted)† Supply voltage, VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 V Input voltage, VI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 V Operating free-air temperature range, TA: SN74ALS280 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0°C to 70°C Storage temperature range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −65°C to 150°C † Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. 2 • POST OFFICE BOX 655303 DALLAS, TEXAS 75265 POST OFFICE BOX 1443 HOUSTON, TEXAS 77251−1443 • 

 

  

 SDAS038C − DECEMBER 1982 − REVISED DECEMBER 1994 recommended operating conditions SN74ALS280 MIN NOM MAX 4.5 5 5.5 UNIT VCC VIH Supply voltage VIL IOH Low-level input voltage 0.8 V High-level output current −2.6 mA IOL TA Low-level output current 24 mA 70 °C High-level input voltage 2 Operating free-air temperature V V 0 electrical characteristics over recommended operating free-air temperature range (unless otherwise noted) PARAMETER VIK VOH SN74ALS280 TYP† MAX TEST CONDITIONS MIN VCC = 4.5 V, VCC = 4.5 V to 5.5 V, II = − 18 mA IOH = − 0.4 mA VCC = 4.5 V, IOH = − 2.6 mA IOL = 12 mA VOL VCC = 4.5 V II IIH VCC = 5.5 V, VCC = 5.5 V, IIL IO‡ VCC = 5.5 V, VCC = 5.5 V, −1.5 VCC − 2 2.4 IOL = 24 mA VI = 7 V VO = 2.25 V −30 V V 3.3 0.25 0.4 0.35 0.5 0.1 VI = 2.7 V VI = 0.4 V UNIT V mA 20 µA −0.1 mA −112 mA ICC VCC = 5.5 V 10 16 mA † All typical values are at VCC = 5 V, TA = 25°C. ‡ The output conditions have been chosen to produce a current that closely approximates one half of the true short-circuit output current, IOS. switching characteristics (see Figure 1) PARAMETER FROM (INPUT) TO (OUTPUT) tPLH tPHL Any Σ EVEN tPLH tPHL Any Σ ODD VCC = 4.5 V to 5.5 V, CL = 50 pF, RL = 500 Ω, TA = MIN to MAX§ SN74ALS280 MIN MAX 3 20 3 20 3 20 4 22 UNIT ns ns § For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions. • POST OFFICE BOX 655303 DALLAS, TEXAS 75265 POST OFFICE BOX 1443 HOUSTON, TEXAS 77251−1443 • 3 

 

  

 SDAS038C − DECEMBER 1982 − REVISED DECEMBER 1994 absolute maximum ratings over operating free-air temperature range (unless otherwise noted)† Supply voltage, VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 V Input voltage, VI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 V Operating free-air temperature range, TA: SN74AS280 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0°C to 70°C Storage temperature range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −65°C to 150°C † Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. recommended operating conditions SN74AS280 MIN NOM MAX 4.5 5 5.5 UNIT VCC VIH Supply voltage VIL IOH Low-level input voltage 0.8 V High-level output current −2 mA IOL TA Low-level output current 20 mA 70 °C High-level input voltage 2 Operating free-air temperature V V 0 electrical characteristics over recommended operating free-air temperature range (unless otherwise noted) PARAMETER SN74AS280 TYP‡ MAX TEST CONDITIONS MIN VIK VOH VCC = 4.5 V, VCC = 4.5 V to 5.5 V, II = − 18 mA IOH = − 2 mA VOL II VCC = 4.5 V, VCC = 5.5 V, IOL = 20 mA VI = 7 V IIH IIL IO§ VCC = 5.5 V, VCC = 5.5 V, VI = 2.7 V VI = 0.4 V VCC = 5.5 V, VCC = 5.5 V VO = 2.25 V −1.5 VCC − 2 UNIT V V 0.35 −30 0.5 V 0.1 mA 20 µA −0.5 mA −112 mA ICC 25 35 mA ‡ All typical values are at VCC = 5 V, TA = 25°C. § The output conditions have been chosen to produce a current that closely approximates one half of the true short-circuit output current, IOS. switching characteristics (see Figure 1) PARAMETER FROM (INPUT) TO (OUTPUT) VCC = 4.5 V to 5.5 V, CL = 50 pF, RL = 500 Ω, TA = MIN to MAX¶ UNIT SN74AS280 tPLH tPHL Any Σ EVEN tPLH tPHL Any Σ ODD MIN MAX 3 12 3 11 3 12 3 11.5 ¶ For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions. 4 • POST OFFICE BOX 655303 DALLAS, TEXAS 75265 POST OFFICE BOX 1443 HOUSTON, TEXAS 77251−1443 • ns ns 

 

  

 SDAS038C − DECEMBER 1982 − REVISED DECEMBER 1994 APPLICATION INFORMATION 25-LINE PARITY GENERATOR/CHECKER 81-LINE PARITY GENERATOR/CHECKER A B C A B C Σ EVEN D D E F E F G Σ ODD G H I H I A A B C B C Σ EVEN D H - Even L = Odd E F G Σ ODD H I H - Odd L = Even A B C A Σ ODD B C D D E F E F G G H I H I Σ EVEN H - Even L = Odd Σ ODD H - Odd L = Even A B C Σ EVEN D D E F E F G Σ ODD Σ ODD Σ ODD To Other SN74AS280s G H I H I Three SN74ALS280/SN74AS280 devices can be used to implement a 25-line parity generator/ checker. Longer word lengths can be implemented by cascading SN74ALS280/SN74AS280 devices. Parity can be generated for word lengths up to 81 bits. As an alternative, the Σ ODD outputs of two or three parity generators/checkers can be decoded with a 2-input (′AS86A or ′ALS86) exclusive-OR gate for 18- or 27-line parity applications. • POST OFFICE BOX 655303 DALLAS, TEXAS 75265 POST OFFICE BOX 1443 HOUSTON, TEXAS 77251−1443 • 5 

 

  

 SDAS038C − DECEMBER 1982 − REVISED DECEMBER 1994 PARAMETER MEASUREMENT INFORMATION SERIES 54ALS/74ALS AND 54AS/74AS DEVICES 7V RL = R1 = R2 VCC S1 RL R1 Test Point From Output Under Test CL (see Note A) From Output Under Test RL Test Point CL (see Note A) CL (see Note A) LOAD CIRCUIT FOR BI-STATE TOTEM-POLE OUTPUTS LOAD CIRCUIT FOR OPEN-COLLECTOR OUTPUTS 3.5 V Timing Input Test Point From Output Under Test LOAD CIRCUIT FOR 3-STATE OUTPUTS 3.5 V High-Level Pulse 1.3 V R2 1.3 V 1.3 V 0.3 V 0.3 V tsu Data Input tw th 3.5 V 1.3 V 3.5 V Low-Level Pulse 1.3 V 0.3 V 1.3 V 0.3 V VOLTAGE WAVEFORMS PULSE DURATIONS VOLTAGE WAVEFORMS SETUP AND HOLD TIMES 3.5 V Output Control (low-level enabling) 1.3 V 1.3 V 0.3 V tPZL Waveform 1 S1 Closed (see Note B) tPLZ 3.5 V Input tPZH 1.3 V 0.3 V tPHL tPLH VOH In-Phase Output VOL 0.3 V 1.3 V 1.3 V VOL tPLH tPHL VOH 1.3 V 1.3 V [3.5 V 1.3 V tPHZ Waveform 2 S1 Open (see Note B) 1.3 V VOH Out-of-Phase Output (see Note C) 0.3 V [0 V 1.3 V 1.3 V VOL VOLTAGE WAVEFORMS PROPAGATION DELAY TIMES VOLTAGE WAVEFORMS ENABLE AND DISABLE TIMES, 3-STATE OUTPUTS NOTES: A. CL includes probe and jig capacitance. B. Waveform 1 is for an output with internal conditions such that the output is low except when disabled by the output control. Waveform 2 is for an output with internal conditions such that the output is high except when disabled by the output control. C. When measuring propagation delay items of 3-state outputs, switch S1 is open. D. All input pulses have the following characteristics: PRR ≤ 1 MHz, tr = tf = 2 ns, duty cycle = 50%. E. The outputs are measured one at a time with one transition per measurement. Figure 1. Load Circuits and Voltage Waveforms 6 • POST OFFICE BOX 655303 DALLAS, TEXAS 75265 POST OFFICE BOX 1443 HOUSTON, TEXAS 77251−1443 • PACKAGE OPTION ADDENDUM www.ti.com 10-Dec-2020 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Pins Package Drawing Qty Eco Plan (2) Lead finish/ Ball material MSL Peak Temp Op Temp (°C) Device Marking (3) (4/5) (6) SN74AS280N ACTIVE PDIP N 14 25 RoHS & Green NIPDAU N / A for Pkg Type 0 to 70 SN74AS280N SN74AS280NSR ACTIVE SO NS 14 2000 RoHS & Green NIPDAU Level-1-260C-UNLIM 0 to 70 74AS280 (1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device. (2) RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may reference these types of products as "Pb-Free". RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption. Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of