SN74ALVCH16821
3.3-V 20-BIT BUS-INTERFACE FLIP-FLOP
WITH 3-STATE OUTPUTS
SCES037C – JULY 1995 – REVISED FEBRUARY 1999
DGG OR DL PACKAGE
(TOP VIEW)
Member of the Texas Instruments
Widebus Family
EPIC (Enhanced-Performance Implanted
CMOS) Submicron Process
1OE
1Q1
1Q2
GND
1Q3
1Q4
1CLK
1D1
1D2
GND
1D3
1D4
1
56
55
54
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
2
ESD Protection Exceeds 2000 V Per
MIL-STD-883, Method 3015; Exceeds 200 V
Using Machine Model (C = 200 pF, R = 0)
3
4
5
Latch-Up Performance Exceeds 250 mA Per
JESD 17
6
V
V
7
CC
CC
1Q5
1Q6
1Q7
GND
1Q8
1Q9
1Q10
2Q1
2Q2
2Q3
GND
2Q4
2Q5
2Q6
1D5
1D6
1D7
GND
1D8
1D9
1D10
2D1
2D2
2D3
GND
2D4
2D5
2D6
8
Bus Hold on Data Inputs Eliminates the
Need for External Pullup/Pulldown
Resistors
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
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 operation.
CC
TheSN74ALVCH16821 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.
V
V
CC
CC
2Q7
2Q8
GND
2Q9
2Q10
2OE
2D7
2D8
GND
2D9
2D10
2CLK
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.
To ensure the high-impedance state during power up or power down, OE should be tied to V through a pullup
CC
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.
Copyright 1999, 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.
1
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265