SN74BCT2414DWG4

     
  SCBS059B − MARCH 1989 − REVISED NOVEMBER 1993 • • • • • • • DW OR N PACKAGE (TOP VIEW) BiCMOS Design Substantially Reduces Standby Current Two Independent 2-Line to 4-Line Decoders or One 3-Line to 8-Line Decoder Separate Enable Inputs for Easy Cascading Two Supply Voltage Terminals (VCC and Vbat ) Built-In Supply-Voltage Monitor for VCC Automatic Cut Off of Outputs During VCC Fail Package Options Include Plastic Small-Outline (DW) Packages and Standard Plastic 300-mil DIPs (N) VS SD 1A 2A 1B 2B 1G 2G G GND 1 20 2 19 3 18 4 17 5 16 6 15 7 14 8 13 9 12 10 11 VCC Vbat 1Y0 1Y1 1Y2 1Y3 2Y0 2Y1 2Y2 2Y3 description The SN74BCT2414 is a decoder specially designed to be used in memory systems with battery backup during power failure. The two independent 2-line to 4-line decoders with separate and common control inputs may be externally cascaded to implement a 3-line to 8-line decoder. The circuit has two supply voltage inputs: the voltage monitor (bandgap) is powered via the VCC terminal; the internal logic of the circuit is powered via the Vbat terminal. In case VCC drops below 3.65 V (nominal), the voltage monitor forces the voltage-control (VS) and decoder outputs (Y) to the high level. VS may be used to disconnect the supply voltage of the memories (Vbat) from the system supply. This output is switched off when the on-chip supply voltage monitor detects a power failure. The SN74BCT2414 is characterized for operation from 0°C to 70°C. Copyright  1993, Texas Instruments Incorporated    !"# $ %&'# "$  (&)*%"# +"#', +&%#$ %! # $('%%"#$ (' #-' #'!$  '."$ $#&!'#$ $#"+"+ /""#0, +&%# (%'$$1 +'$ # '%'$$"*0 %*&+' #'$#1  "** (""!'#'$, • DALLAS, TEXAS 75265 • HOUSTON, TEXAS 77251−1443 POST OFFICE BOX 655303 POST OFFICE BOX 1443 2−1 
     
  SCBS059B − MARCH 1989 − REVISED NOVEMBER 1993 logic symbol† VCC SD G 1A 1B 1G VCOMP 20 2 5 7 EN X/Y 0 1 1 2 2 EN 3 2A 2B 2G 4 6 8 X/Y 0 1 1 2 2 EN 3 † This symbol is in accordance with ANSI/IEEE Std 91-1984 and IEC Publication 617-12. 2−2 VS & 9 3 1 X > 3.65 V • POST OFFICE BOX 655303 DALLAS, TEXAS 75265 POST OFFICE BOX 1443 HOUSTON, TEXAS 77251−1443 • 18 17 16 15 14 13 12 11 1Y0 1Y1 1Y2 1Y3 2Y0 2Y1 2Y2 2Y3 
     
  SCBS059B − MARCH 1989 − REVISED NOVEMBER 1993 logic diagram (positive logic) VCC 20 VCOMP Vbat SD 1A 1 19 18 2 1G 2G G 17 5 15 2B 1Y1 1Y2 1Y3 7 8 9 14 2A 1Y0 3 16 1B VS 4 13 12 6 2Y0 2Y1 2Y2 11 2Y3 • POST OFFICE BOX 655303 DALLAS, TEXAS 75265 POST OFFICE BOX 1443 HOUSTON, TEXAS 77251−1443 • 2−3 
     
  SCBS059B − MARCH 1989 − REVISED NOVEMBER 1993 FUNCTION TABLES INPUTS CONTROL OUTPUTS SELECT G 1G SD 1B 1A 1Y0 1Y1 1Y2 1Y3 H X X X X H H H H X H X X X H H H H X X L X X H H H H L L H L L L H H H L L H L H H L H H L L H H L H H L H L L H H H H H H L INPUTS CONTROL G OUTPUTS SELECT 2G SD 2B 2A 2Y0 2Y1 2Y2 2Y3 H X X X X H H H H X H X X X H H H H H X X L X X H H H L H H L L L H H H L H H L H H L H H L H H H L H H L H L H H H H H H H L NOTE: For a 3-line to 8-line decoder, the following pins must be shorted: 1G to 2G, 1A to 2A and 1B to 2B. absolute maximum ratings over operating free-air temperature range (unless otherwise noted)† Supply voltage range, Vbat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −0.5 V to 7 V Supply voltage range, VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −0.5 V to 7 V Supply voltage VCC with respect to Vbat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −1.5 V Input voltage range, VI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −0.5 V to VCC + 0.5 V Off-state output voltage range at VS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −0.5 V to 7 V Voltage range applied to any Y output in the power-off state . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −0.5 V to 7 V Voltage applied to any Y output in the power-off state with respect to Vbat . . . . . . . . . . . . . . . . . . . . . . . . 0.5 V Operating free-air temperature range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 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 2−4 • POST OFFICE BOX 655303 DALLAS, TEXAS 75265 POST OFFICE BOX 1443 HOUSTON, TEXAS 77251−1443 • 
     
  SCBS059B − MARCH 1989 − REVISED NOVEMBER 1993 recommended operating conditions MIN NOM MAX UNIT VCC Vbat Supply voltage 4.5 5 5.5 V Supply voltage 4.5 5 5.5 V VIH VIL High-level input voltage Low-level input voltage 0.8 V IIK IOH Input clamp current −18 mA −400 µA 2 V High-level output current Y outputs 8 IOL Low-level output current tt TA Input transition time 0 10 ns / V Operating free-air temperature 0 70 °C VS outputs 20 mA electrical characteristics over recommended operating free-air temperature range (unless otherwise noted) PARAMETER VIK TEST CONDITIONS VCC = 4.5 V, II = −18 mA IOH = − 20 µA Vbat = VCC = 4.5 V VOH IOH = − 400 µA IOH = − 50 µA Vbat = 2 V, VCC = 0, VOL All except VS Vbat = VCC = 4.5 V IOL = 4 mA IOL = 8 mA VS Vbat = VCC = 4.5 V, IOL = 20 mA Vbat = VCC = 5.5 V, Vbat = VCC = 5.5 V, VI = 5.5 V VI = 2.7 V Vbat = VCC = 5.5 V, Vbat = 4.5 V, VI = 0.5 V VCC = 0 Vbat = VCC = 5.5 V, VO = 2.25 V Outputs high VT‡ II VS ICC Vbat = VCC = 5.5 V MAX UNIT −1.2 V 4.4 3.5 V 1.8 0.4 0.5 Ci Any Y VS VCC = 0 Outputs high Vbat = VCC = 5.5 V Outputs low Vbat = VCC = 5 V, VI = 0 or 3 V −30 V 100 µA ± 20 µA ± 20 µA 1 µA −200 mA 3 3 1 10 20 3 4 6.5 Vbat = VCC = 0 V 1 Outputs low Vbat = 2.5 V, Ibat Co TYP† 3.65 IIH IIL IOH IO§ MIN 5 mA µA A mA pF pF † All typical values are at VCC = 5 V, TA = 25°C. ‡ This value represents the VCC monitor threshold voltage. Typical range is from 3.5 V to 3.8 V. § This output condition has been chosen to produce a current that closely approximates one half of the short-circuit output current, IOS. Not more than one output should be tested at a time, and the duration of the test should not exceed one second. • POST OFFICE BOX 655303 DALLAS, TEXAS 75265 POST OFFICE BOX 1443 HOUSTON, TEXAS 77251−1443 • 2−5 
     
  SCBS059B − MARCH 1989 − REVISED NOVEMBER 1993 switching characteristics (see Note 1) PARAMETER FROM (INPUT) TO (OUTPUT) tPLH tPHL A or B Any Y tPLH tPHL Any G Any Y tPLH tPHL SD Any Y VCC = 4.5 V to 5.5 V, CL = 50 pF, R1 = 500 Ω, R2 = 500 Ω, TA = MIN to MAX† VCC = 5 V, CL = 50 pF, R1 = 500 Ω, R2 = 500 Ω, TA = 25°C MIN TYP MAX MIN MAX 1 5 10 1 12 2 5.8 10 2 12 1 4.5 9 1 10 2 5.5 9 2 11 2 6.5 11 2 12 2 6.5 11 2 12 UNIT ns ns ns switching characteristics (see Note 1) PARAMETER FROM (INPUT) TO (OUTPUT) tPLH tPHL VCC Any Y tPLH tPHL VCC VS VCC = 4.5 V to 5.5 V, CL = 50 pF, R1 = 500 Ω, R2 = 500 Ω, TA = MIN to MAX† VCC = 5 V, CL = 50 pF, R1 = 500 Ω, R2 = 500 Ω, TA = 25°C MIN TYP MAX MIN MAX 10 15 25 50 10 250 45 100 15 250 10 28 50 10 250 20 50 100 20 250 † For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions. NOTE 1: Load circuits and voltage waveforms are shown in Section 1. 2−6 • POST OFFICE BOX 655303 DALLAS, TEXAS 75265 POST OFFICE BOX 1443 HOUSTON, TEXAS 77251−1443 • UNIT ns ns 
     
  SCBS059B − MARCH 1989 − REVISED NOVEMBER 1993 APPLICATION INFORMATION A typical application circuit for a battery-buffered memory in a microcomputer system is shown in Figure 1 which uses the SN74BCT2414. When power fails, the supply-voltage supervisor (TL7705) resets the microcomputer and disables the memory by switching the shutdown input SD of the memory decoder to a logic zero. All memory decoder outputs are forced to a logic one. Abnormal write commands from the microprocessor, which may be issued during further voltage breakdown, no longer affect the contents of the memory. When the system supply voltage becomes lower than approximately 3.65 V, the voltage monitor inside the SN74BCT2414 memory decoder disconnects the input buffers of this circuit from the decoding logic internally and keeps all outputs at a logic one. The VS output is also switched off, disconnecting the system supply voltage from the memory circuits. During this low-voltage condition, the memory decoder and the memory circuits are supplied by the battery. Microprocessor 8 D0 − D7 D3 VCC A0 − A15 16 DBIN R3 R1 Q1 WE R2 D1 1N4148 1 kΩ RESET SN74BCT2414 VS VCC Vbat 1G 1Y0 2G 1Y1 1B 1Y2 2B 1Y3 1A 2Y0 2A 2Y1 SD 2Y2 G 2Y3 A15 5V A14 TL7705A 10 kΩ A13 VCC RES SENSE RESIN VCC CE VREF Ct GND 0.1 µF A0 − A12 OE 0.1 µF WR 8- × 8K-Byte CMOS RAM For further information on this device, please contact factory. Figure 1. Memory System With Battery Backup • POST OFFICE BOX 655303 DALLAS, TEXAS 75265 POST OFFICE BOX 1443 HOUSTON, TEXAS 77251−1443 • 2−7 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) SN74BCT2414DW ACTIVE SOIC DW 20 25 RoHS & Green NIPDAU Level-1-260C-UNLIM 0 to 70 BCT2414 SN74BCT2414N ACTIVE PDIP N 20 20 RoHS & Non-Green NIPDAU N / A for Pkg Type 0 to 70 SN74BCT2414N (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