Texas Instruments SN74ALS29821DW, SN74ALS29821DWR, SN74ALS29821NT Datasheet
SN54ALS29821 . . . JT PACKAGE
SN74ALS29821 . . . DW OR NT PACKAGE
(TOP VIEW)
1
2
3
4
5
6
7
8
9
10
11
12
24
23
22
21
20
19
18
17
16
15
14
13
OE
1D
2D
3D
4D
5D
6D
7D
8D
9D
10D
GND
V
CC
1Q
2Q
3Q
4Q
5Q
6Q
7Q
8Q
9Q
10Q
CLK
SN54ALS29821, SN74ALS29821
10-BIT BUS-INTERFACE FLIP-FLOPS
WITH 3-STATE OUTPUTS
SDAS145B – JANUARY 1986 – REVISED JANUARY 1995
Copyright 1995, Texas Instruments Incorporated
1
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
• Functionally Equivalent to AMD’s AM29821
• Provide Extra Data Width Necessary for
Wider Address/Data Paths or Buses With
Parity
• Outputs Have Undershoot-Protection
Circuitry
• Power-Up High-Impedance State
• Buffered Control Inputs Reduce
dc Loading Effects
• Package Options Include Plastic
Small-Outline (DW) Packages and Standard
Plastic (NT) and Ceramic (JT) 300-mil DIPs
description
These 10-bit edge-triggered D-type flip-flops
feature 3-state outputs designed specifically for
driving highly capacitive or relatively low-impedance loads. These devices are particularly suitable for
implementing wider buffer registers, I/O ports, bidirectional bus drivers with parity, and working registers.
On the positive transition of the clock (CLK) input, the Q outputs are true to the data (D) input.
A buffered output-enable (OE
) input can place the ten outputs in either a normal logic state (high or low logic
levels) or a high-impedance state. The outputs also are in the high-impedance state during power-up and
power-down conditions. The outputs remain in the high-impedance state while the device is powered down. 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 interface or pullup components.
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.
The SN54ALS29821 is characterized for operation over the full military temperature range of –55°C to 125°C.
The SN74ALS29821 is characterized for operation from 0°C to 70°C.
FUNCTION TABLE
(each flip-flop)
INPUTS
OUTPUT
OE CLK D
Q
L ↑ H H
L ↑ LL
LLX Q
0
HXX Z
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.
SN54ALS29821, SN74ALS29821
10-BIT BUS-INTERFACE FLIP-FLOPS
WITH 3-STATE OUTPUTS
SDAS145B – JANUARY 1986 – REVISED JANUARY 1995
2
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
logic symbol
†
6Q
18
7Q
17
8Q
16
9Q
15
10Q
14
7
6D
8
7D
9
8D
10
9D
EN
1
1Q
23
3
2D
4
3D
5
4D
6
5D
2Q
22
3Q
21
4Q
20
5Q
19
13
CLK
OE
11
10D
C1
1D
2
1D
†
This symbol is in accordance with ANSI/IEEE Std 91-1984 and IEC Publication 617-12.
logic diagram (positive logic)
1D
OE
2
1
13
1Q
23
CLK
1D
To Nine Other Channels
C1
absolute maximum ratings over operating free-air temperature range (unless otherwise noted)
‡
Supply voltage, V
CC
7 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Input voltage, V
I
5.5 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Voltage applied to a disabled 3-state output 5.5 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating free-air temperature range, T
A
: SN54ALS29821 –55°C to 125°C. . . . . . . . . . . . . . . . . . . . . . . . . . .
SN74ALS29821 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.
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