PDF《SN54AC245, SN74AC245》

SN54AC245, SN74AC245 OCTAL BUS TRANSCEIVERS WITH 3-STATE OUTPUTS SCAS461F ? FEBRUARY

1995 ? REVISED OCTOBER

2003 1 POST OFFICE BOX

655303 ? DALLAS, TEXAS

75265 D 2-V to 6-V VCC Operation D Inputs Accept Voltages to

6 V D Max tpd of

7 ns at

5 V description/ordering information The '

AC245 octal bus transceivers are designed for asynchronous two-way communication between data buses.

The control-function implementation minimizes external timing requirements. When the output-enable (OE) is low, the device passes noninverted data from the A bus to the B bus or from the B bus to the A bus, depending on the logic level at the direction control (DIR) input. A high on OE disables the device so that the buses are effectively isolated. To ensure the high-impedance state during power up or power down, OE should be tied to VCC through a pullup resistor;

the minimum value of the resistor is determined by the current-sinking capability of the driver. ORDERING INFORMATION TA PACKAGE? ORDERABLE PART NUMBER TOP-SIDE MARKING PDIP ? N Tube SN74AC245N SN74AC245N SOIC DW Tube SN74AC245DW AC245 SOIC ? DW Tape and reel SN74AC245DWR AC245 ?40°C to 85°C SOP ? NS Tape and reel SN74AC245NSR AC245

40 C to

85 C SSOP ? DB Tape and reel SN74AC245DBR AC245 TSSOP PW Tube SN74AC245PW AC245 TSSOP ? PW Tape and reel SN74AC245PWR AC245 CDIP ? J Tube SNJ54AC245J SNJ54AC245J ?55°C to 125°C CFP ? W Tube SNJ54AC245W SNJ54AC245W

55 C to

125 C LCCC ? FK Tube SNJ54AC245FK SNJ54AC245FK ? Package drawings, standard packing quantities, thermal data, symbolization, and PCB design guidelines are available at www.ti.com/sc/package. Copyright ? 2003, 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. SN54AC245 . . . J OR W PACKAGE SN74AC245 . . . DB, DW, N, NS, OR PW PACKAGE (TOP VIEW)

3 2

1 20

19 9

10 11

12 13

4 5

6 7

8 18

17 16

15 14 B1 B2 B3 B4 B5 A3 A4 A5 A6 A7 SN54AC245 . . . FK PACKAGE (TOP VIEW) A2 A1 DIR B7 B6 OE A8 GND B8 V CC

1 2

3 4

5 6

7 8

9 10

20 19

18 17

16 15

14 13

12 11 DIR A1 A2 A3 A4 A5 A6 A7 A8 GND VCC OE B1 B2 B3 B4 B5 B6 B7 B8 Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. On products compliant to MIL-PRF-38535, all parameters are tested unless otherwise noted. On all other products, production processing does not necessarily include testing of all parameters. SN54AC245, SN74AC245 OCTAL BUS TRANSCEIVERS WITH 3-STATE OUTPUTS SCAS461F ? FEBRUARY

1995 ? REVISED OCTOBER

2003 2 POST OFFICE BOX

655303 ? DALLAS, TEXAS

75265 FUNCTION TABLE INPUTS OPERATION OE DIR OPERATION L L H L H X B data to A bus A data to B bus Isolation logic diagram (positive logic) DIR OE A1 B1

1 2

18 19 To Seven Other Channels absolute maximum ratings over operating free-air temperature range (unless otherwise noted)? Supply voltage range, VCC ?0.5 V to

7 V Input voltage range, VI (see Note 1) ?0.5 V to VCC + 0.5 V Output voltage range, VO (see Note 1) ?0.5 V to VCC + 0.5 V Input clamp current, IIK (VI <

0 or VI >

VCC) ±20 mA Output clamp current, IOK (VO <

0 or VO >

VCC) ±20 mA Continuous output current, IO (VO =

0 to VCC) ±50 mA Continuous current through VCC or GND ±200 mA Package thermal impedance, θJA (see Note 2): DB package 70°C/W DW package 58°C/W N package 69°C/W NS package 60°C/W PW package 83°C/W Storage temperature range, Tstg ?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. NOTES: 1. The input and output voltage ratings may be exceeded if the input and output current ratings are observed. 2. The package thermal impedance is calculated in accordance with JESD 51-7. SN54AC245, SN74AC245 OCTAL BUS TRANSCEIVERS WITH 3-STATE OUTPUTS SCAS461F ? FEBRUARY