TI SN74LVC646DW

SN74LVC646
OCTAL BUS TRANSCEIVER AND REGISTER
WITH 3-STATE OUTPUTS
SCAS302A – JANUARY 1993 – REVISED JULY 1995
D
D
D
D
D
EPIC  (Enhanced-Performance Implanted
CMOS) Submicron Process
Typical VOLP (Output Ground Bounce)
< 0.8 V at VCC = 3.3 V, TA = 25°C
Typical VOHV (Output VOH Undershoot)
> 2 V at VCC = 3.3 V, TA = 25°C
Latch-Up Performance Exceeds 250 mA
Per JEDEC Standard JESD-17
Package Options Include Plastic
Small-Outline (DW), Shrink Small-Outline
(DB), and Thin Shrink Small-Outline (PW)
Packages
DB, DW, OR PW PACKAGE
(TOP VIEW)
CLKAB
SAB
DIR
A1
A2
A3
A4
A5
A6
A7
A8
GND
description
1
24
2
23
3
22
4
21
5
20
6
19
7
18
8
17
9
16
10
15
11
14
12
13
VCC
CLKBA
SBA
OE
B1
B2
B3
B4
B5
B6
B7
B8
This octal bus transceiver and register is designed for 2.7-V to 3.6-V VCC operation.
The SN74LVC646 consists of bus-transceiver circuits, D-type flip-flops, and control circuitry arranged for
multiplexed transmission of data directly from the input bus or from the internal registers. Data on the A or B bus
is clocked into the registers on the low-to-high transition of the appropriate clock (CLKAB or CLKBA) input.
Figure 1 illustrates the four fundamental bus-management functions that can be performed with the
SN74LVC646.
Output-enable (OE) and direction-control (DIR) inputs control the transceiver functions. In the transceiver
mode, data present at the high-impedance port can be stored in either register or in both.
The select-control (SAB and SBA) inputs can multiplex stored and real-time (transparent mode) data. DIR
determines which bus receives data when OE is low. In the isolation mode (OE high), A data can be stored in
one register and B data can be stored in the other register.
When an output function is disabled, the input function is still enabled and can be used to store and transmit
data. Only one of the two buses, A or B, may be driven at a time.
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.
The SN74LVC646 is characterized for operation from – 40°C to 85°C.
FUNCTION TABLE
INPUTS
DATA I/Os
OPERATION OR FUNCTION
OE
DIR
CLKAB
CLKBA
SAB
SBA
A1 – A8
B1 – B8
X
X
↑
X
X
X
Input
Unspecified†
X
X
X
↑
X
X
Unspecified†
Input
Store A, B unspecified†
Store B, A unspecified†
H
X
↑
↑
X
X
Input
Input
Store A and B data
H
X
H or L
H or L
X
X
Input disabled
Input disabled
Isolation, hold storage
L
L
X
X
X
L
Output
Input
Real-time B data to A bus
L
L
X
H or L
X
H
Output
Input
Stored B data to A bus
L
H
X
X
L
X
Input
Output
Real-time A data to B bus
L
H
H or L
X
H
X
Input
Output
Stored A data to B bus
† The data output functions may be enabled or disabled by various signals at the OE and DIR inputs. Data input functions are always enabled;
i.e., data at the bus pins is stored on every low-to-high transition of the clock inputs.
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.
EPIC is a trademark of Texas Instruments Incorporated.
Copyright  1995, 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.
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
1
SN74LVC646
OCTAL BUS TRANSCEIVER AND REGISTER
WITH 3-STATE OUTPUTS
21
OE
L
3
DIR
L
1
23
CLKAB CLKBA
X
X
2
SAB
X
BUS B
BUS A
BUS A
BUS B
SCAS302A – JANUARY 1993 – REVISED JULY 1995
22
SBA
L
21
OE
L
3
DIR
H
3
DIR
X
X
X
1
23
CLKAB CLKBA
X
↑
X
↑
↑
↑
2
SAB
X
X
X
22
SBA
X
X
X
21
OE
L
L
22
SBA
X
BUS B
3
DIR
L
H
STORAGE FROM
A, B, OR A AND B
1
CLKAB
X
H or L
23
CLKBA
H or L
X
2
SAB
X
H
TRANSFER STORED DATA
TO A AND/OR B
Figure 1. Bus-Management Functions
2
2
SAB
L
BUS A
BUS A
21
OE
X
X
H
23
CLKBA
X
REAL-TIME TRANSFER
BUS A TO BUS B
BUS B
REAL-TIME TRANSFER
BUS B TO BUS A
1
CLKAB
X
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• DALLAS, TEXAS 75265
22
SBA
H
X
SN74LVC646
OCTAL BUS TRANSCEIVER AND REGISTER
WITH 3-STATE OUTPUTS
SCAS302A – JANUARY 1993 – REVISED JULY 1995
logic symbol†
21
OE
DIR
CLKBA
SBA
CLKAB
SAB
A1
3
23
22
1
2
G3
3 EN1 [BA]
3 EN2 [AB]
C4
G5
C6
G7
≥1
4
1
5
6D
7
1
A2
A3
A4
A5
A6
A7
A8
4D
5
20
B1
1
≥1
2
7
5
19
6
18
7
17
8
16
9
15
10
14
11
13
B2
B3
B4
B5
B6
B7
B8
† This symbol is in accordance with ANSI/IEEE Std 91-1984 and IEC Publication 617-12.
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
3
SN74LVC646
OCTAL BUS TRANSCEIVER AND REGISTER
WITH 3-STATE OUTPUTS
SCAS302A – JANUARY 1993 – REVISED JULY 1995
logic diagram (positive logic)
OE
DIR
CLKBA
SBA
CLKAB
SAB
21
3
23
22
1
2
One of Eight
Channels
1D
C1
A1
4
20
1D
C1
To Seven Other Channels
4
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
B1
SN74LVC646
OCTAL BUS TRANSCEIVER AND REGISTER
WITH 3-STATE OUTPUTS
SCAS302A – JANUARY 1993 – REVISED JULY 1995
absolute maximum ratings over operating free-air temperature range (unless otherwise noted)†
Supply voltage range, VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 0.5 V to 4.6 V
Input voltage range, VI: Except I/O ports (see Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 0.5 V to 6.5 V
I/O ports (see Notes 1 and 2) . . . . . . . . . . . . . . . . . . . . . . . . . . – 0.5 V to VCC + 0.5 V
Output voltage range, VO (see Notes 1 and 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 0.5 V to VCC + 0.5 V
Input clamp current, IIK (VI < 0) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 50 mA
Output clamp current, IOK (VO < 0 or VO > VCC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ± 50 mA
Continuous output current, IO (VO = 0 to VCC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ± 50 mA
Continuous current through VCC or GND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ± 100 mA
Maximum power dissipation at TA = 55°C (in still air) (see Note 3): DB package . . . . . . . . . . . . . . . . . 0.65 W
DW package . . . . . . . . . . . . . . . . . 1.7 W
PW package . . . . . . . . . . . . . . . . . . 0.7 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 negative-voltage ratings may be exceeded if the input and output clamp-current ratings are observed.
2. This value is limited to 4.6 V maximum.
3. The maximum package power dissipation is calculated using a junction temperature of 150°C and a board trace length of 750 mils.
For more information, refer to the Package Thermal Considerations application note in the 1994 ABT Advanced BiCMOS Technology
Data Book, literature number SCBD002B.
recommended operating conditions (see Note 3)
VCC
VIH
Supply voltage
VIL
Low-level input voltage
High-level input voltage
VI
Input voltage
VO
Output voltage
MIN
MAX
2.7
3.6
VCC = 2.7 V to 3.6 V
VCC = 2.7 V to 3.6 V
2
Control inputs
0
5.5
Data inputs
0
VCC
VCC
IOH
High level output current
High-level
IOL
Low level output current
Low-level
VCC = 2.7 V
VCC = 3 V
∆t /∆v
Input transition rise or fall rate
TA
Operating free-air temperature
NOTE 4: Unused inputs must be held high or low to prevent them from floating.
POST OFFICE BOX 655303
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V
V
0.8
0
VCC = 2.7 V
VCC = 3 V
UNIT
– 12
12
– 24
24
V
V
V
mA
mA
0
10
ns / V
– 40
85
°C
5
SN74LVC646
OCTAL BUS TRANSCEIVER AND REGISTER
WITH 3-STATE OUTPUTS
SCAS302A – JANUARY 1993 – REVISED JULY 1995
electrical characteristics over recommended operating free-air temperature range (unless
otherwise noted)
PARAMETER
VCC†
MIN to MAX
TEST CONDITIONS
IOH = – 100 µA
IOH = – 24 mA
IOL = 100 µA
TYP‡
MAX
VCC – 0.2
2.2
2.7 V
IOH = – 12 mA
VOH
MIN
3V
2.4
3V
2
UNIT
V
MIN to MAX
0.2
VOL
IOL = 12 mA
IOL = 24 mA
2.7 V
0.4
3V
0.55
II
IOZ§
VI = 5.5 V or GND
VO = VCC or GND
3.6 V
±5
µA
3.6 V
± 10
µA
ICC
nICC
VI = VCC or GND,
One input at VCC – 0.6 V,
3.6 V
20
µA
3 V to 3.6 V
500
µA
IO = 0
Other inputs at VCC or GND
V
Ci
Control
inputs
VI = VCC or GND
3.3 V
4.6
pF
Cio
A or B
ports
VO = VCC or GND
3.3 V
7.2
pF
† For conditions shown as MIN or MAX, use the appropriate values under recommended operating conditions.
‡ All typical values are measured at VCC = 3.3 V, TA = 25°C.
§ For I/O ports, the parameter IOZ includes the input leakage current.
timing characteristics over recommended operating free-air temperature range (unless otherwise
noted) (see Figure 2)
VCC = 3.3 V
± 0.3 V
MIN
MAX
VCC = 2.7 V
MIN
UNIT
MAX
tw
tsu
Pulse duration
5
5
ns
Setup time, data before CLK↑
5
5
ns
th
Hold time, data after CLK↑
1
1
ns
switching characteristics over recommended operating free-air temperature range, CL = 50 pF
(unless otherwise noted) (see Figure 2)
PARAMETER
6
VCC = 2.7 V
TO
(OUTPUT)
A or B
B or A
1.5
8
9.2
fmax
tpd
VCC = 3.3 V
± 0.3 V
FROM
(INPUT)
MIN
MAX
100
MIN
UNIT
MAX
80
MHz
ns
CLK
A or B
1.5
9
11
SBA or SAB
A or B
1.5
9
11
ten
tdis
OE
A or B
1.5
8.5
9.5
ns
OE
A or B
1.5
8.5
9.5
ns
ten
tdis
DIR
A or B
1.5
9
10
ns
DIR
A or B
1.5
9
10
ns
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
SN74LVC646
OCTAL BUS TRANSCEIVER AND REGISTER
WITH 3-STATE OUTPUTS
SCAS302A – JANUARY 1993 – REVISED JULY 1995
operating characteristics, VCC = 3.3 V, TA = 25°C
PARAMETER
Cpd
d
TEST CONDITIONS
Outputs enabled
Power dissipation capacitance per transceiver
pF
CL = 50 pF,
Outputs disabled
TYP
38
f = 10 MHz
4.2
UNIT
pF
PARAMETER MEASUREMENT INFORMATION
6V
S1
500 Ω
From Output
Under Test
Open
GND
CL = 50 pF
(see Note A)
500 Ω
TEST
S1
tpd
tPLZ/tPZL
tPHZ/tPZH
Open
6V
GND
2.7 V
LOAD CIRCUIT FOR OUTPUTS
1.5 V
Timing Input
0V
tw
tsu
2.7 V
1.5 V
Input
th
2.7 V
1.5 V
1.5 V
Data Input
1.5 V
0V
0V
VOLTAGE WAVEFORMS
PULSE DURATION
VOLTAGE WAVEFORMS
SETUP AND HOLD TIMES
2.7 V
1.5 V
Input
0V
tPLH
1.5 V
tPLH
VOH
Output
1.5 V
1.5 V
VOL
1.5 V
0V
tPLZ
Output
Waveform 1
S1 at 6 V
(see Note B)
VOH
VOL
tPHL
1.5 V
tPZL
tPHL
1.5 V
Output
2.7 V
Output
Control
1.5 V
Output
Waveform 2
S1 at GND
(see Note B)
VOLTAGE WAVEFORMS
PROPAGATION DELAY TIMES
INVERTING AND NONINVERTING OUTPUTS
1.5 V
tPZH
3V
VOL + 0.3 V
VOL
tPHZ
1.5 V
VOH – 0.3 V
VOH
[0V
VOLTAGE WAVEFORMS
ENABLE AND DISABLE TIMES
LOW- AND HIGH-LEVEL ENABLING
NOTES: A. CL includes probe and jig capacitance.
B. Waveform 1 is for an output with internal conditions such that the output is low except when disabled by the output control.
Waveform 2 is for an output with internal conditions such that the output is high except when disabled by the output control.
C. All input pulses are supplied by generators having the following characteristics: PRR ≤ 10 MHz, ZO = 50 Ω, tr ≤ 2.5 ns, tf ≤ 2.5 ns.
D. The outputs are measured one at a time with one transition per measurement.
E. tPLZ and tPHZ are the same as tdis.
F. tPZL and tPZH are the same as ten.
G. tPLH and tPHL are the same as tpd.
Figure 2. Load Circuit and Voltage Waveforms
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
7
SN74LVC646
OCTAL BUS TRANSCEIVER AND REGISTER
WITH 3-STATE OUTPUTS
SCAS302A – JANUARY 1993 – REVISED JULY 1995
8
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
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Copyright  1999, Texas Instruments Incorporated