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Details, datasheet, quote on part number:74AC646
 
 
Part:74AC646
Category:Logic => Bus Interface => Bus Oriented Circuits
Description:Octal Bus Transceiver/register With 3-STATE Outputs
Company:Fairchild Semiconductor
Datasheet:Download 74AC646 datasheet   File size : 82 kB
Request For quote:  Find where to buy 74AC646
 



Datasheet text preview:
74AC646 · 74ACT646 Octal Transceiver/Register with 3-STATE Outputs

November 1988 Revised October 2000

74AC646 · 74ACT646 Octal Transceiver/Register with 3-STATE Outputs
General Description
The AC/ACT646 consist of registered bus transceiver circuits, with outputs, D-type flip-flops and control circuitry providing multiplexed transmission of data directly from the input bus or from the internal storage registers. Data on the A or B bus will be loaded into the respective registers on the LOW-to-HIGH transition of the appropriate clock pin (CPAB or CPBA). The four fundamental data handling functions available are illustrated in Figures 1, 2, 3, and Figure 4.

Features
s Independent registers for A and B buses s Multiplexed real-time and stored data transfers s 3-STATE outputs s 300 mil dual-in-line package s Outputs source/sink 24 mA s ACT646 has TTL compatible inputs

Ordering Code:
Order Number 74AC646SC 74AC646SPC 74ACT646SC 74ACT646SPC Package Number M24B N24C M24B N24C Package Description 24-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300 Wide 24-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide 24-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300 Wide 24-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide

Device also available in Tape and Reel. Specify by appending suffix letter "X" to the ordering code.

Logic Symbols

Connection Diagram

IEEE/IEC

Pin Descriptions
Pin Names A0­A7 B0­B7 CPAB, CPBA SAB, SBA G DIR
FACT is a trademark of Fairchild Semiconductor Corporation.

Description Data Register A Inputs Data Register A Outputs Data Register B Inputs Data Register B Outputs Clock Pulse Inputs Transmit/Receive Inputs Output Enable Input Direction Control Input

© 2000 Fairchild Semiconductor Corporation

DS010132

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74AC646 · 74ACT646

Function Table
Inputs G H H H L L L L L L L L DI R X X X H H H H L L L L CPAB CPBA H or L H or L S AB X X X L L H H X X X X SBA X X X X X X X L L H H Output Input Input Input Input Data I/O (Note 1) Function A0­A7 B0 ­ B7 Isolation Clock An Data into A Register Clock Bn Data into B Register An to Bn--Real Time (Transparent Mode) Output Clock An Data into A Register A Register to Bn (Stored Mode) Clock An Data into A Register and Output to Bn Bn to An --Real Time (Transparent Mode) Clock Bn Data into B Register B Register to An (Stored Mode) Clock Bn Data into B Register and Output to An


X


X X X X

X

H or L


X X X X

X

H or L

H = HIGH Voltage Level L = LOW Voltage Level X = Immaterial = LOW-to-HIGH Transition



X



Note 1: The data output functions may be enabled or disabled by various signals at the G and DIR inputs. Data input functions are always enabled; i.e., data at the bus pins will be stored on every LOW-to-HIGH transition of the appropriate clock inputs.

Real Time Transfer A-Bus to B-Bus

Real Time Transfer B-Bus to A-Bus

FIGURE 1. Storage from Bus to Register

FIGURE 2. Transfer from Register to Bus

FIGURE 3.

FIGURE 4.

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74AC646 · 74ACT646

Logic Diagram

Please note that this diagram is provided only for the understanding of logic operations and should not be used to estimate propagation delays.

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74AC646 · 74ACT646

Absolute Maximum Ratings(Note 2)
Supply Voltage (VCC) DC Input Diode Current (IIK) VI = -0.5V VI = VCC + 0.5V DC Input Voltage (VI) DC Output Diode Current (IOK) VO = -0.5V VO = VCC + 0.5V DC Output Voltage (VO) DC Output Source or Sink Current (IO) DC VCC or Ground Current per Output Pin (ICC or IGND) Storage Temperature (TSTG) Junction Temperature (TJ) PDIP 140°C

-0.5V to +7.0V -20 mA +20 mA -0.5V to VCC + 0.5V -20 mA +20 mA -0.5V to VCC + 0.5V ±50 mA ±50 mA -65°C to +150°C

Recommended Operating Conditions
Supply Voltage (VCC) AC ACT Input Voltage (VI) Output Voltage (VO) Operating Temperature (TA) Minimum Input Edge Rate (V/t) AC Devices VIN from 30% to 70% of VCC VCC @ 3.3V, 4.5V, 5.5V Minimum Input Edge Rate (V/t) ACT Devices VIN from 0.8V to 2.0V VCC @ 4.5V, 5.5V 125 mV/ns
Note 2: Absolute maximum ratings are those values beyond which damage to the device may occur. The databook specifications should be met, without exception, to ensure that the system design is reliable over its power supply, temperature, and output/input loading variables. Fairchild does not recommend operation of FACT circuits outside databook specifications.

2.0V to 6.0V 4.5V to 5.5V 0V to VCC 0V to VCC

-40°C to +85°C

125 mV/ns

DC Electrical Characteristics for AC
Symbol VIH Parameter Minimum HIGH Level Input Voltage VIL Maximum LOW Level Input Voltage VOH Minimum HIGH Level Output Voltage VCC (V) 3.0 4.5 5.5 3.0 4.5 5.5 3.0 4.5 5.5 3.0 4.5 5.5 VOL Maximum LOW Level Output Voltage 3.0 4.5 5.5 3.0 4.5 5.5 IIN (Note 5) IOLD IOHD ICC (Note 5) IOZT Maximum Input Leakage Current Minimum Dynamic Output Current (Note 4) Maximum Quiescent Supply Current Maximum I/O Leakage Current 5.5 ±0.6 ±6.0 µA 5.5 5.5 5.5 5.5 8.0 0.002 0.001 0.001 TA = +25°C Typ 1.5 2.25 2.75 1.5 2.25 2.75 2.99 4.49 5.49 2.1 3.15 3.85 0.9 1.35 1.65 2.9 4 .4 5 .4 2.56 3.86 4.86 0.1 0.1 0.1 0.36 0.36 0.36 ± 0.1 TA = -40°C to +85°C Guaranteed Limits 2.1 3.15 3.85 0.9 1.35 1.65 2.9 4.4 5.4 VIN = VIL or VIH 2.46 3.76 4.76 0.1 0.1 0.1 VIN = VIL or VIH 0.44 0.44 0.44 ± 1.0 75 -75 80.0 µA mA mA µA V IOH = 12 mA IOL = 24 mA IOH = 24 mA (Note 3) VI = VCC, GND VOLD = 1.65V Max VOHD = 3.85V Min VIN = VCC or GND VI (OE) = VIL, VIH VI = VCC, GND VO = VCC, GND
Note 3: All outputs loaded; thresholds on input associated with output under test. Note 4: Maximum test duration 2.0 ms, one output loaded at a time. Note 5: IIN and ICC @ 3.0V are guaranteed to be less than or equal to the respective limit @ 5.5V VCC.

Units

Conditions VOUT = 0.1V

V

or VCC - 0.1V VOUT = 0.1V

V

or VCC - 0.1V

V

IOUT = -50 µA

IOH = -12 mA V IOH = -24 mA IOH = -24 mA (Note 3) V IOUT = 50 µA

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74AC646 · 74ACT646

DC Electrical Characteristics for ACT
Symbol VIH VIL VOH Parameter Minimum HIGH Level Input Voltage Maximum LOW Level Input Voltage Minimum HIGH Level Output Voltage VCC (V) 4.5 5.5 4.5 5.5 4.5 5.5 4.5 5.5 VOL Maximum LOW Level Output Voltage 4.5 5.5 4.5 5.5 IIN ICCT IOLD IOHD ICC IOZT Maximum Input Leakage Current Maximum ICC/Input Minimum Dynamic Output Current (Note 7) Maximum Quiescent Supply Current Maximum I/O Leakage Current 5.5 ±0.6 ±6.0 µA 5.5 5.5 5.5 5.5 5.5 8 .0 0.6 0 .001 0 .001 TA = +25°C Typ 1 .5 1 .5 1 .5 1.5 4 .49 5 .49 2.0 2.0 0.8 0.8 4 .4 5 .4 3.86 4.86 0.1 0.1 0.36 0.36 ± 0.1 TA = -40°C to +85°C Guaranteed Limits 2 .0 2 .0 0 .8 0.8 4.4 5.4 3.76 4.76 0 .1 0 .1 0.44 0.44 ± 1.0 1.5 75 -75 80.0 µA mA mA mA µA V Units V V V Conditions VOUT = 0.1V or VCC - 0.1V VOUT = 0.1V or VCC - 0.1V IOUT = -50 µA VIN = VIL or VIH V IOH= -24 mA IOH= -24 mA (Note 6) IOUT = 50 µA VIN = VIL or VIH V IOL= 24 mA IOL = 24 mA (Note 6) VI = VCC, GND VI = VCC - 2.1V VOLD = 1.65V Max VOHD = 3.85V Min VIN = VCC or GND VI (OE) = VIL, VIH VI = VCC, GND VO = VCC, GND
Note 6: All outputs loaded; thresholds on input associated with output under test. Note 7: Maximum test duration 2.0 ms, one output loaded at a time.

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