SN74ALVCH16821
3.3-V 20-BIT BUS-INTERFACE FLIP-FLOP
WITH 3-STATE OUTPUTS
SCES037C – JULY 1995 – REVISED FEBRUARY 1999
D
Member of the Texas Instruments
D
Widebus
EPIC
Family
(Enhanced-Performance Implanted
CMOS) Submicron Process
D
ESD Protection Exceeds 2000 V Per
MIL-STD-883, Method 3015; Exceeds 200 V
Using Machine Model (C = 200 pF, R = 0)
D
Latch-Up Performance Exceeds 250 mA Per
JESD 17
D
Bus Hold on Data Inputs Eliminates the
Need for External Pullup/Pulldown
Resistors
D
Package Options Include Plastic 300-mil
Shrink Small-Outline (DL) and Thin Shrink
Small-Outline (DGG) Packages
description
This 20-bit bus-interface flip-flop is designed for
1.65-V to 3.6-V V
The SN74AL VCH16821 can be used as two 10-bit
flip-flops or one 20-bit flip-flop. The 20 flip-flops
are edge-triggered D-type flip-flops. On the
positive transition of the clock (CLK) input, the
device provides true data at the Q outputs.
A buffered output-enable (OE
to place the ten outputs in either a normal logic
state (high or low logic levels) or the
high-impedance state. In the high-impedance
state, the outputs neither load nor drive the bus
lines significantly. The high-impedance state and
increased drive provide the capability to drive bus
lines without need for interface or pullup
components.
operation.
CC
) input can be used
DGG OR DL PACKAGE
(TOP VIEW)
1OE
1
56
1Q1
2
55
1Q2
3
54
GND
GND
1Q10
GND
GND
2Q10
1Q3
1Q4
V
CC
1Q5
1Q6
1Q7
1Q8
1Q9
2Q1
2Q2
2Q3
2Q4
2Q5
2Q6
V
CC
2Q7
2Q8
2Q9
2OE
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
53
52
51
50
49
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
1CLK
1D1
1D2
GND
1D3
1D4
V
CC
1D5
1D6
1D7
GND
1D8
1D9
1D10
2D1
2D2
2D3
GND
2D4
2D5
2D6
V
CC
2D7
2D8
GND
2D9
2D10
2CLK
OE
does not affect the internal operation of the flip-flops. Old data can be retained or new data can be entered
while the outputs are in the high-impedance state.
T o 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.
Active bus-hold circuitry is provided to hold unused or floating data inputs at a valid logic level.
The SN74ALVCH16821 is characterized for operation from –40°C to 85°C.
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 and Widebus are trademarks of 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
Copyright 1999, Texas Instruments Incorporated
1
SN74ALVCH16821
3.3-V 20-BIT BUS-INTERFACE FLIP-FLOP
WITH 3-STATE OUTPUTS
SCES037C – JULY 1995 – REVISED FEBRUARY 1999
FUNCTION TABLE
(each 10-bit flip-flop)
INPUTS
OE CLK D
L ↑ H H
L ↑ LL
LH or L X Q
H X X Z
OUTPUT
Q
0
logic symbol
†
1OE
1CLK
2OE
2CLK
1D1
1D2
1D3
1D4
1D5
1D6
1D7
1D8
1D9
1D10
2D1
2D2
2D3
2D4
2D5
2D6
2D7
2D8
2D9
2D10
1
56
28
29
55
54
52
51
49
48
47
45
44
43
42
41
40
38
37
36
34
33
31
30
EN2
EN4
1D
3D
C1
C3
2
10
12
13
14
15
16
17
19
20
21
23
24
26
27
1Q1
3
1Q2
5
1Q3
6
1Q4
8
1Q5
9
1Q6
1Q7
1Q8
1Q9
1Q10
2Q1
2Q2
2Q3
2Q4
2Q5
2Q6
2Q7
2Q8
2Q9
2Q10
2
4
†
This symbol is in accordance with ANSI/IEEE Std 91-1984 and IEC Publication 617-12.
2
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
logic diagram (positive logic)
1
1OE
SN74ALVCH16821
3.3-V 20-BIT BUS-INTERFACE FLIP-FLOP
WITH 3-STATE OUTPUTS
SCES037C – JULY 1995 – REVISED FEBRUARY 1999
1CLK
1D1
2OE
2CLK
2D1
56
55
28
29
42
One of Ten
Channels
One of Ten
Channels
C1
1D
To Nine Other Channels
C1
1D
15
2
1Q1
2Q1
To Nine Other Channels
absolute maximum ratings over operating free-air temperature range (unless otherwise noted)
Supply voltage range, V
Input voltage range, V
Output voltage range, V
Input clamp current, I
Output clamp current, I
Continuous output current, I
Continuous current through each V
Package thermal impedance, θ
Storage temperature range, T
†
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 negative-voltage and output voltage ratings may be exceeded if the input and output current ratings are observed.
2. This value is limited to 4.6 V maximum.
3. The package thermal impedance is calculated in accordance with JESD 51.
–0.5 V to 4.6 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CC
(see Note 1) –0.5 V to 4.6 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
I
(see Notes 1 and 2) –0.5 V to VCC + 0.5 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
O
(VI < 0) –50 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
IK
(VO < 0) –50 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
OK
±50 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
O
JA
or GND ±100 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CC
(see Note 3): DGG package 81°C/W. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DL package 74°C/W. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
–65°C to 150°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
stg
†
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
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