English
Language : 

SN74ALVCH16821_08 Datasheet, PDF (1/12 Pages) Texas Instruments – 3.3-V 20-BIT BUS-INTERFACE FLIP-FLOP WITH 3-STATE OUTPUTS
www.ti.com
FEATURES
• Member of the Texas Instruments Widebus™
Family
• Bus Hold on Data Inputs Eliminates the Need
for External Pullup/Pulldown Resistors
• Latch-Up Performance Exceeds 250 mA Per
JESD 17
• ESD Protection Exceeds JESD 22
– 2000-V Human-Body Model (A114-A)
– 200-V Machine Model (A115-A)
DESCRIPTION/ORDERING INFORMATION
This 20-bit bus-interface flip-flop is designed for
1.65-V to 3.6-V VCC operation.
The SN74ALVCH16821 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) input can be used 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.
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.
SN74ALVCH16821
3.3-V 20-BIT BUS-INTERFACE FLIP-FLOP
WITH 3-STATE OUTPUTS
SCES037F – JULY 1995 – REVISED SEPTEMBER 2004
DGG OR DL PACKAGE
(TOP VIEW)
1OE 1
1Q1 2
1Q2 3
GND 4
1Q3 5
1Q4 6
VCC 7
1Q5 8
1Q6 9
1Q7 10
GND 11
1Q8 12
1Q9 13
1Q10 14
2Q1 15
2Q2 16
2Q3 17
GND 18
2Q4 19
2Q5 20
2Q6 21
VCC 22
2Q7 23
2Q8 24
GND 25
2Q9 26
2Q10 27
2OE 28
56 1CLK
55 1D1
54 1D2
53 GND
52 1D3
51 1D4
50 VCC
49 1D5
48 1D6
47 1D7
46 GND
45 1D8
44 1D9
43 1D10
42 2D1
41 2D2
40 2D3
39 GND
38 2D4
37 2D5
36 2D6
35 VCC
34 2D7
33 2D8
32 GND
31 2D9
30 2D10
29 2CLK
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.
Active bus-hold circuitry holds unused or undriven inputs at a valid logic state. Use of pullup or pulldown resistors
with the bus-hold circuitry is not recommended.
TA
-40°C to 85°C
ORDERING INFORMATION
PACKAGE (1)
ORDERABLE PART NUMBER
TOP-SIDE MARKING
SSOP - DL
Tube
Tape and reel
SN74ALVCH16821DL
SN74ALVCH16821DLR
ALVCH16821
TSSOP - DGG Tape and reel SN74ALVCH16821DGGR
ALVCH16821
(1) Package drawings, standard packing quantities, thermal data, symbolization, and PCB design guidelines are available at
www.ti.com/sc/package.
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.
Widebus is a trademark of Texas Instruments.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 1995–2004, Texas Instruments Incorporated