|
Details, datasheet, quote on part number:SN74ALS638ADW
| |
Datasheet text preview:
SN74ALS638A, SN74ALS639A, SN74AS638A, SN74AS639 OCTAL BUS TRANSCEIVERS
SDAS123A DECEMBER 1983 REVISED JANUARY 1995
· · · ·
Bidirectional Bus Transceivers in High-Density 20-Pin Packages Choice of True or Inverting Logic A-Bus Outputs Are Open Collector; B-Bus Outputs Are 3 State Package Options Include Plastic Small-Outline (DW) Packages and Standard Plastic (N) 300-mil DIPs
DEVICE A OUTPUT Open collector Open collector B OUTPUT 3 state 3 state LOGIC Inverting True
DW OR N PACKAGE (TOP VIEW)
SN74ALS638A, SN74AS638A SN74ALS639A, SN74AS639
DIR A1 A2 A3 A4 A5 A6 A7 A8 GND
1 2 3 4 5 6 7 8 9 10
20 19 18 17 16 15 14 13 12 11
VC C OE B1 B2 B3 B4 B5 B6 B7 B8
description
These octal bus transceivers are designed for asynchronous two-way communication between open-collector and 3-state buses. The devices transmit data from the A bus (open-collector) to the B bus (3 state) or from the B bus to the A bus, depending on the logic level at the direction-control (DIR) input. The output-enable (OE) input can be used to disable the device so the buses are isolated. The -1 version of SN74ALS638A is identical to the standard version, except that the recommended maximum IOL is increased to 48 mA. The SN74ALS638A, SN74ALS639A, SN74AS638A, and SN74AS639 are characterized for operation from 0°C to 70°C.
FUNCTION TABLE INPUTS OE L L H DIR L H X OPERATION SN74ALS638A SN74AS638A B data to A bus A data to B bus Isolation SN74ALS639A SN74AS639 B data to A bus A data to B bus Isolation
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.
Copyright © 1995, Texas Instruments Incorporated
POST OFFICE BOX 655303
· DALLAS, TEXAS 75265
1
SN74ALS638A, SN74ALS639A, SN74AS638A, SN74AS639 OCTAL BUS TRANSCEIVERS
SDAS123A DECEMBER 1983 REVISED JANUARY 1995
logic symbols
SN74ALS638A, SN74AS638A OE DIR 19 1 G3 3 EN1 [BA] 3 EN2 [AB] 1 2 A2 A3 A4 A5 A6 A7 A8 3 4 5 6 7 8 9 17 16 15 14 13 12 11 B2 B3 B4 B5 B6 B7 B8 A2 A3 A4 A5 A6 A7 A8 3 4 5 6 7 8 9 18 B1 OE DIR 19 1 SN74ALS639A, SN74AS639 G3 3 EN1 [BA] 3 EN2 [AB] 1 2 17 16 15 14 13 12 11 B2 B3 B4 B5 B6 B7 B8 18 B1
A1
2
A1
2
These symbols are in accordance with ANSI/IEEE Std 91-1984 and IEC Publication 617-12.
logic diagrams (positive logic)
SN74ALS638A, SN74AS638A OE 19 OE 19 SN74ALS639A, SN74AS639
DIR
1
DIR
1
A1
2
18
B1
A1
2
18
B1
To Seven Other Transceivers
To Seven Other Transceivers
absolute maximum ratings over operating free-air temperature range (unless otherwise noted)
Supply voltage, VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 V Input voltage, VI: All inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 V A-bus I/O ports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 V B-bus I/O ports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.5 V Operating free-air temperature range, TA: SN74ALS638A, SN74ALS639A . . . . . . . . . . . . . . . . . 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
SN74ALS638A, SN74ALS639A, SN74AS638A, SN74AS639 OCTAL BUS TRANSCEIVERS
SDAS123A DECEMBER 1983 REVISED JANUARY 1995
recommended operating conditions
SN74ALS638A SN74ALS639A MIN VCC VIH VIL VOH IOH IOL Supply voltage High-level input voltage Low-level input voltage High-level output voltage High-level output current Low-level output current output current A ports B ports A or B ports or ports 0 4.5 2 0.8 5.5 15 24 48 70 NOM 5 MAX 5.5 V V V V mA mA °C UNIT
TA Operating free-air temperature Applies only to the SN74ALS638A-1 version and only if VCC is between 4.75 V and 5.25 V
electrical characteristics over recommended operating free-air temperature range (unless otherwise noted)
PARAMETER VIK IOH VOH TEST CONDITIONS VCC = 4.5 V, VCC = 4.5 V, VCC = 4.5 V to 5.5 V, B ports VCC = 4 5 V 4.5 II = 18 mA VOH = 5.5 V IOH = 0.4 mA IOH = 3 mA IOH = 15 mA IOL = 12 mA IOL = 24 mA IOL = 48 mA VI = 7 V VI = 5.5 V VI = 2 7 V 2.7 VI = 0 4 V 0.4 VO = 2.25 V Outputs high Outputs low Outputs disabled Outputs high SN74ALS639A VCC = 5.5 V Outputs low Outputs disabled 30 18 26 16 25 30 33 VCC 2 2.4 2 0.25 0.35 0.35 0.4 0.5 0.5 0.1 0.1 20 20 0.1 0.1 112 30 41 30 40 50 mA mA µA mA mA V 3.2 SN74ALS638A SN74ALS639A MIN A ports TYP MAX 1.5 0.1 V mA V UNIT
VOL
A or B ports Control inputs A or B ports Control inputs A or B ports§ Control inputs A or B ports§ B ports SN74ALS638A
VCC = 4.5 V
II IIH IIL IO¶
VCC = 5 5 V 5.5 VCC = 5 5 V 5.5 V, VCC = 5 5 V 5.5 V, VCC = 5.5 V, VCC = 5.5 V
ICC
54 Applies only to the SN74ALS638A-1 version and only if VCC is between 4.75 V and 5.25 V All typical values are at VCC = 5 V, TA = 25°C. § For I/O ports, 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
|
|
