Biboritas geniales

DM74LS244 Octal 3-STATE Buffer/Line Driver/Line Receiver

August 1986 Revised March 2000

DM74LS244 Octal 3-STATE Buffer/Line Driver/Line Receiver
General Description
These buffers/line drivers are designed to improve both the performance and PC board density of 3-STATE buffers/ drivers employed as memory-address drivers, clock drivers, and bus-oriented transmitters/receivers. Featuring 400mV of hysteresis at each low current PNP data line input, they provide improved noise rejection and high fanout outputs and can be used to drive terminated lines down to 133Ω.

Features
s 3-STATE outputs drive bus lines directly s PNP inputs reduce DC loading on bus lines s Hysteresis at data inputs improves noise margins s Typical IOL (sink current) 24 mA s Typical IOH (source current) −15 mAs Typical propagation delay times Inverting Noninverting 10.5 ns 12 ns 18 ns

s Typical enable/disable time Inverting Noninverting 130 mW 135 mW

s Typical power dissipation (enabled)

Ordering Code:
Order Number DM74LS244WM DM74LS244SJ DM74LS244N Package Number M20B M20D N20A Package Description 20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300 Wide 20-Lead SmallOutline Package (SOP), EIAJ TYPE II, 5.3mm Wide 20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide

Devices also available in Tape and Reel. Specify by appending the suffix letter “X” to the ordering code.

Connection Diagram

Function Table
Inputs G L L H
L = LOW Logic Level H = HIGH Logic Level X = Either LOW or HIGH Logic Level Z = High Impedance

Output A L H X Y L H Z© 2000 Fairchild Semiconductor Corporation

DS008442

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Absolute Maximum Ratings(Note 1)
Supply Voltage Input Voltage Operating Free Air Temperature Range Storage Temperature Range 7V 7V 0°C to +70°C −65°C to +150°C
Note 1: The “Absolute Maximum Ratings” are those values beyond which the safety of the device cannot be guaranteed. The device should notbe operated at these limits. The parametric values defined in the Electrical Characteristics tables are not guaranteed at the absolute maximum ratings. The “Recommended Operating Conditions” table will define the conditions for actual device operation.

Recommended Operating Conditions
Symbol VCC VIH VIL IOH IOL TA Supply Voltage HIGH Level Input Voltage LOW Level Input Voltage HIGH Level OutputCurrent LOW Level Output Current Free Air Operating Temperature 0 Parameter Min 4.75 2 0.8 −15 24 70 Nom 5 Max 5.25 Units V V V mA mA °C

Electrical Characteristics
over recommended operating free air temperature range (unless otherwise noted) Symbol VI HYS VOH Parameter Input Clamp Voltage Hysteresis (VT+ − VT−) Data Inputs Only HIGH Level Output Voltage VCC = Min, VIH = Min VIL = Max, IOH =−1 mA VCC = Min, VIH = Min VIL = Max, IOH = −3 mA VCC = Min, VIH = Min VIL = 0.5V, IOH = Max VOL LOW Level Output Voltage VCC = Min VIL = Max VIH = Min IOZH IOZL II IIH IIL IOS ICC Off-State Output Current, HIGH Level Voltage Applied Off-State Output Current, LOW Level Voltage Applied Input Current at Maximum Input Voltage HIGH Level Input Current LOW Level Input Current Short Circuit Output CurrentSupply Current VCC = Max VCC = Max VCC = Max (Note 3) VCC = Max, Outputs Open
Note 2: All typicals are at VCC = 5V, TA = 25°C. Note 3: Not more than one output should be shorted at a time, and the duration should not exceed one second.

Conditions VCC = Min, II = −18 mA VCC = Min

Min

Typ (Note 2)

Max −1.5

Units V V

0.2

0.4

2.7 2.4 2 IOL = 12 mA IOL = Max VO = 2.7V VO =0.4V VI = 7V VI = 2.7V V I = 0.4V Outputs HIGH Outputs LOW Outputs Disabled −0.5 −40 13 27 32 0.4 0.5 20 −20 0.1 20 −200 −225 23 46 54 mA V µA µA mA µA µA mA 3.4 V

VCC = Max VIL = Max VIH = Min VCC = Max

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Switching Characteristics
at VCC = 5V, TA = 25°C Symbol tPLH tPHL tPZL tPZH tPLZ tPHZ tPLH tPHL tPZL tPZH Parameter Propagation Delay Time...