SN74ALS990 8-BIT D-TYPE TRANSPARENT READ-BACK LATCH SDAS027B - APRIL 1984 - REVISED JANUARY 1995 * * * * DW OR N PACKAGE (TOP VIEW) 3-State I/O-Type Read-Back Inputs Bus-Structured Pinout True Logic Outputs Package Options Include Plastic Small-Outline (DW) Packages and Standard Plastic (N) 300-mil DIPs OERB 1D 2D 3D 4D 5D 6D 7D 8D GND description This 8-bit latch is designed specifically for storing the contents of the input data bus and providing the capability of reading back the stored data onto the input data bus. 1 20 2 19 3 18 4 17 5 16 6 15 7 14 8 13 9 12 10 11 VCC 1Q 2Q 3Q 4Q 5Q 6Q 7Q 8Q LE The eight latches are transparent D-type latches. While the latch-enable (LE) input is high, the Q outputs follow the data (D) inputs. Read back is provided through the output-enable (OERB) input. When OERB is taken low, the data present at the output of the data latches is allowed to pass back onto the input data bus. When OERB is taken high, the output of the data latches is isolated from the D inputs. OERB does not affect the internal operation of the latches; however, precautions should be taken not to create a bus conflict. The SN74ALS990 is characterized for operation from 0C to 70C. logic symbol 1 OERB LE 1D 11 2 EN2 C1 1D 19 2 2D 3D 4D 5D 6D 7D 8D 3 18 4 17 5 16 6 15 7 14 8 13 9 12 1Q 2Q 3Q 4Q 5Q 6Q 7Q 8Q This symbol is in accordance with ANSI/IEEE Std 91-1984 and IEC Publication 617-12. Copyright 1995, Texas Instruments Incorporated PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. POST OFFICE BOX 655303 * DALLAS, TEXAS 75265 1 SN74ALS990 8-BIT D-TYPE TRANSPARENT READ-BACK LATCH SDAS027B - APRIL 1984 - REVISED JANUARY 1995 logic diagram (positive logic) OERB LE 1D 1 11 2 1D 19 1Q C1 To Seven Other Channels timing diagram Data Bus Input Data tsu Read Back Input Data th LE tsu ten tdis OERB tpd tpd Q This setup time ensures that the read-back circuit will not create a conflict on the input data bus. absolute maximum ratings over operating free-air temperature range (unless otherwise noted) Supply voltage, VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 V Input voltage, VI (OERB and LE) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 V Voltage applied to D inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.5 V Operating free-air temperature range, TA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0C to 70C Storage temperature range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - 65C to 150C 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 SN74ALS990 8-BIT D-TYPE TRANSPARENT READ-BACK LATCH SDAS027B - APRIL 1984 - REVISED JANUARY 1995 recommended operating conditions VCC VIH Supply voltage VIL Low-level input voltage IOH High level output current High-level IOL Low level output current Low-level tw Pulse duration, LE high High-level input voltage MIN NOM MAX 4.5 5 5.5 2 Q - 2.6 D - 0.4 Q 24 D 8 10 10 Data before OERB 10 tsu Setup time th TA Hold time, data after LE 5 Operating free-air temperature 0 V V 0.8 Data before LE UNIT V mA mA ns ns ns 70 C electrical characteristics over recommended operating free-air temperature range (unless otherwise noted) PARAMETER VIK VOH TEST CONDITIONS All outputs VCC = 4.5 V, VCC = 4.5 V to 5.5 V, II = - 18 mA IOH = - 0.4 mA Q VCC = 4.5 V, D VCC = 4 4.5 5V IOH = - 2.6 mA IOL = 4 mA VOL Q II OERB, LE D inputs VCC = 4 4.5 5V VCC = 5 5.5 5V UNIT - 1.2 V VCC - 2 2.4 V 3.2 IOL = 8 mA IOL = 12 mA 0.35 0.5 0.25 0.4 IOL = 24 mA VI = 5.5 V 0.35 0.5 0.1 VI = 7 V VCC = 5 5.5 5V V, VI = 2 2.7 7V IIL OERB, LE D inputs 5V VCC = 5 5.5 V, 4V VI = 0 0.4 VCC = 5.5 V, VO = 2.25 V Outputs high VCC = 5.5 V, OERB high MAX 0.4 OERB, LE D inputs ICC TYP 0.25 IIH IO MIN Outputs low 0.1 20 20 - 0.1 - 0.1 - 30 -112 27 50 40 70 V mA A mA mA mA All typical values are at VCC = 5 V, TA = 25C. For I/O ports (QA thru QH), the parameters IIH and IIL include the off-state output current. The output conditions have been chosen to produce a current that closely approximates one half of the true short-circuit output current, IOS. POST OFFICE BOX 655303 * DALLAS, TEXAS 75265 3 SN74ALS990 8-BIT D-TYPE TRANSPARENT READ-BACK LATCH SDAS027B - APRIL 1984 - REVISED JANUARY 1995 switching characteristics (see Figure 1) PARAMETER FROM ((INPUT)) TO (OUTPUT) ( ) tPLH tPHL D Q tPLH tPHL LE Q OERB D ten tdis VCC = 4.5 V to 5.5 V, CL = 50 pF, TA = MIN to MAX MIN MAX 4 17 5 24 6 26 8 26 4 21 ns 19 ns 4 OERB D For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions. ten = tPZH or tPZL tdis = tPHZ or tPLZ 4 POST OFFICE BOX 655303 * DALLAS, TEXAS 75265 UNIT ns ns SN74ALS990 8-BIT D-TYPE TRANSPARENT READ-BACK LATCH SDAS027B - APRIL 1984 - REVISED JANUARY 1995 PARAMETER MEASUREMENT INFORMATION 7V S1 1 k Test Point From Output Under Test CL (see Note A) CL (see Note A) 500 LOAD CIRCUIT FOR Q OUTPUTS 1 k LOAD CIRCUIT FOR D OUTPUTS 3.5 V Timing Input Test Point From Output Under Test 1.3 V 3.5 V High-Level Pulse 1.3 V 1.3 V 0.3 V 0.3 V tw th tsu 3.5 V Data Input 1.3 V 1.3 V 0.3 V VOLTAGE WAVEFORMS SETUP AND HOLD TIMES 1.3 V 0.3 V 3.5 V Output Control (low-level enabling) 1.3 V tPHL tPLH VOH 1.3 V 1.3 V tPHL Out-of-Phase Output (see Note B) Waveform 1 S1 Closed (see Note C) VOL tPLH VOH 1.3 V 1.3 V VOL VOLTAGE WAVEFORMS PROPAGATION DELAY TIMES 1.3 V 0.3 V tPZL 1.3 V tPLZ 0.3 V In-Phase Output 1.3 V VOLTAGE WAVEFORMS PULSE DURATIONS 3.5 V 1.3 V Input 3.5 V Low-Level Pulse [3.5 V 1.3 V tPHZ tPZH Waveform 2 S1 Open (see Note C) VOL 0.3 V VOH 1.3 V 0.3 V [0 V VOLTAGE WAVEFORMS ENABLE AND DISABLE TIMES, 3-STATE OUTPUTS NOTES: A. CL includes probe and jig capacitance. B. When measuring propagation delay times of 3-state outputs, switch S1 is open. C. 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. D. All input pulses have the following characteristics: PRR 1 MHz, tr = tf = 2 ns, duty cycle = 50%. Figure 1. Load Circuits and Voltage Waveforms POST OFFICE BOX 655303 * DALLAS, TEXAS 75265 5 PACKAGE OPTION ADDENDUM www.ti.com 10-May-2007 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Drawing Pins Package Eco Plan (2) Qty SN74ALS990DW ACTIVE SOIC DW 20 25 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM SN74ALS990DWE4 ACTIVE SOIC DW 20 25 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM SN74ALS990DWG4 ACTIVE SOIC DW 20 25 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM SN74ALS990DWR ACTIVE SOIC DW 20 2000 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM SN74ALS990DWRE4 ACTIVE SOIC DW 20 2000 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM SN74ALS990DWRG4 ACTIVE SOIC DW 20 2000 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM SN74ALS990N ACTIVE PDIP N 20 CU NIPDAU N / A for Pkg Type SN74ALS990N3 OBSOLETE PDIP N 20 SN74ALS990NE4 ACTIVE PDIP N 20 Lead/Ball Finish 20 Pb-Free (RoHS) TBD Call TI 20 Pb-Free (RoHS) CU NIPDAU MSL Peak Temp (3) Call TI N / A for Pkg Type (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) Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability information and additional product content details. TBD: The Pb-Free/Green conversion plan has not been defined. Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes. Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used between the die and leadframe. The component is otherwise considered Pb-Free (RoHS compatible) as defined above. Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material) (3) MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature. Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release. In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis. Addendum-Page 1 PACKAGE MATERIALS INFORMATION www.ti.com 11-Mar-2008 TAPE AND REEL INFORMATION *All dimensions are nominal Device SN74ALS990DWR Package Package Pins Type Drawing SOIC DW 20 SPQ Reel Reel Diameter Width (mm) W1 (mm) 2000 330.0 24.4 Pack Materials-Page 1 A0 (mm) B0 (mm) K0 (mm) P1 (mm) W Pin1 (mm) Quadrant 10.8 13.0 2.7 12.0 24.0 Q1 PACKAGE MATERIALS INFORMATION www.ti.com 11-Mar-2008 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) SN74ALS990DWR SOIC DW 20 2000 346.0 346.0 41.0 Pack Materials-Page 2 IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications, enhancements, improvements, and other changes to its products and services at any time and to discontinue any product or service without notice. Customers should obtain the latest relevant information before placing orders and should verify that such information is current and complete. All products are sold subject to TI's terms and conditions of sale supplied at the time of order acknowledgment. TI warrants performance of its hardware products to the specifications applicable at the time of sale in accordance with TI's standard warranty. Testing and other quality control techniques are used to the extent TI deems necessary to support this warranty. Except where mandated by government requirements, testing of all parameters of each product is not necessarily performed. TI assumes no liability for applications assistance or customer product design. Customers are responsible for their products and applications using TI components. To minimize the risks associated with customer products and applications, customers should provide adequate design and operating safeguards. TI does not warrant or represent that any license, either express or implied, is granted under any TI patent right, copyright, mask work right, or other TI intellectual property right relating to any combination, machine, or process in which TI products or services are used. Information published by TI regarding third-party products or services does not constitute a license from TI to use such products or services or a warranty or endorsement thereof. Use of such information may require a license from a third party under the patents or other intellectual property of the third party, or a license from TI under the patents or other intellectual property of TI. Reproduction of TI information in TI data books or data sheets is permissible only if reproduction is without alteration and is accompanied by all associated warranties, conditions, limitations, and notices. Reproduction of this information with alteration is an unfair and deceptive business practice. TI is not responsible or liable for such altered documentation. Information of third parties may be subject to additional restrictions. Resale of TI products or services with statements different from or beyond the parameters stated by TI for that product or service voids all express and any implied warranties for the associated TI product or service and is an unfair and deceptive business practice. TI is not responsible or liable for any such statements. TI products are not authorized for use in safety-critical applications (such as life support) where a failure of the TI product would reasonably be expected to cause severe personal injury or death, unless officers of the parties have executed an agreement specifically governing such use. Buyers represent that they have all necessary expertise in the safety and regulatory ramifications of their applications, and acknowledge and agree that they are solely responsible for all legal, regulatory and safety-related requirements concerning their products and any use of TI products in such safety-critical applications, notwithstanding any applications-related information or support that may be provided by TI. Further, Buyers must fully indemnify TI and its representatives against any damages arising out of the use of TI products in such safety-critical applications. TI products are neither designed nor intended for use in military/aerospace applications or environments unless the TI products are specifically designated by TI as military-grade or "enhanced plastic." Only products designated by TI as military-grade meet military specifications. Buyers acknowledge and agree that any such use of TI products which TI has not designated as military-grade is solely at the Buyer's risk, and that they are solely responsible for compliance with all legal and regulatory requirements in connection with such use. TI products are neither designed nor intended for use in automotive applications or environments unless the specific TI products are designated by TI as compliant with ISO/TS 16949 requirements. Buyers acknowledge and agree that, if they use any non-designated products in automotive applications, TI will not be responsible for any failure to meet such requirements. Following are URLs where you can obtain information on other Texas Instruments products and application solutions: Products Applications Audio www.ti.com/audio Communications and Telecom www.ti.com/communications Amplifiers amplifier.ti.com Computers and Peripherals www.ti.com/computers Data Converters dataconverter.ti.com Consumer Electronics www.ti.com/consumer-apps DLP(R) Products www.dlp.com Energy and Lighting www.ti.com/energy DSP dsp.ti.com Industrial www.ti.com/industrial Clocks and Timers www.ti.com/clocks Medical www.ti.com/medical Interface interface.ti.com Security www.ti.com/security Logic logic.ti.com Space, Avionics and Defense www.ti.com/space-avionics-defense Power Mgmt power.ti.com Transportation and Automotive www.ti.com/automotive Microcontrollers microcontroller.ti.com Video and Imaging www.ti.com/video RFID www.ti-rfid.com Wireless www.ti.com/wireless-apps RF/IF and ZigBee(R) Solutions www.ti.com/lprf TI E2E Community Home Page e2e.ti.com Mailing Address: Texas Instruments, Post Office Box 655303, Dallas, Texas 75265 Copyright (c) 2011, Texas Instruments Incorporated