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ManualsBrandsTEXAS INSTRUMENTS ManualsLogic ICsLogic IC - Custom logic Address decoder SOIC 20

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SCBS059B − MARCH 1989 − REVISED NOVEMBER 1993

2−1

POST OFFICE BOX 655303 • DALLAS, TEXAS 75265

POST OFFICE BOX 1443 • HOUSTON, TEXAS 77251−1443

• 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 (V

and

bat

)

• Built-In Supply-Voltage Monitor for V

• Automatic Cut Off of Outputs During

Fail

• Package Options Include Plastic

Small-Outline (DW) Packages and Standard

Plastic 300-mil DIPs (N)

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 V

terminal; the

internal logic of the circuit is powered via the V

bat

terminal. In case V

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 (V

bat

) 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.

GND

bat

1Y0

1Y1

1Y2

1Y3

2Y0

2Y1

2Y2

2Y3

DW OR N PACKAGE

(TOP VIEW)

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Summary of content (14 pages)

PAGE 1
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 Standa
PAGE 2
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.
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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
PAGE 4
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
PAGE 5
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.
PAGE 6
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.
PAGE 7
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.
PAGE 8
PACKAGE OPTION ADDENDUM www.ti.
PAGE 9
PACKAGE MATERIALS INFORMATION www.ti.com 14-Jul-2012 TAPE AND REEL INFORMATION *All dimensions are nominal Device SN74BCT2414DWR Package Package Pins Type Drawing SOIC DW 20 SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) 2000 330.0 24.4 Pack Materials-Page 1 10.8 B0 (mm) K0 (mm) P1 (mm) W Pin1 (mm) Quadrant 13.0 2.7 12.0 24.
PAGE 10
PACKAGE MATERIALS INFORMATION www.ti.com 14-Jul-2012 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) SN74BCT2414DWR SOIC DW 20 2000 367.0 367.0 45.
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