16
CORPORATE HEADQUARTERS for SALES: for Tech Support:
6024 Silver Creek Valley Road 800-345-7015 or 408-284-8200 408-360-1753
San Jose, CA 95138 fax: 408-284-2775 email: FIFOhelp@idt.com
www.idt.com
DEPTH EXPANSION — IDT72801/72811/72821/72831/72841/72851
can be adapted to applications that require greater than 256/512/1,024/
2,048/4,096/8,192 words. The existence of double enable pins on the read
and write ports allow depth expansion. The Write Enable 2/Load (WENA2,
WENB2) pins are used as a second write enables in a depth expansion
configuration, thus the Programmable flags are set to the default values.
Depth expansion is possible by using one enable input for system control
while the other enable input is controlled by expansion logic to direct the flow
of data. A typical application would have the expansion logic alternate data
access from one device to the next in a sequential manner. These FIFOs operate
in the Depth Expansion configuration when the following conditions are met:
1. WENA2/LDA and WENB2/LDB pins are held HIGH during Reset so
that these pins operate as second Write Enables.
2. External logic is used to control the flow of data.
Please see the Application Note" DEPTH EXPANSION OF IDT'S SYN-
CHRONOUS FIFOs USING THE RING COUNTER APPROACH" for details
of this configuration.
NOTES:
1. Industrial temperature range product for 15ns and 25ns speed grade are available as a standard device.
2. Green parts are available. For specific speeds and packages contact your sales office.
ORDERING INFORMATION
BLANK
3034 drw 19
XXXXX
Device Type
XX
Power Speed Package
Process/
Temperature
Range
Clock Cycle Time
(t
CLK
), Speed in
Nanoseconds
Commercial (0°C to +70°C)
X
256 x 9 Dual SyncFIFO
Thin Quad Flatpack (TQFP, PN64-1)
10
72801
Commercial Only
PF
Low Power
XX
X
L
I
(1)
Industrial (-40°C to +85°C)
TF
Slim Thin Quad Flatpack(STQFP, PP64-1)
15
25
Commercial and Industrial
Commercial and Industrial
72811
72821
72831
72841
72851
512 x 9 Dual SyncFIFO
1,024 x 9 Dual SyncFIFO
2,048 x 9 Dual SyncFIFO
4,096 x 9 Dual SyncFIFO
8,192 x 9 Dual SyncFIFO
X
G
(2)
Green
BLANK
8
Tube or Tray
Tape and Reel
X
DATASHEET DOCUMENT HISTORY
04/24/2001 pgs. 4, 5 and 16.
02/10/2006 pgs. 1 and 16.
01/13/2009 pg. 16.
03/20/2013 pg. 1, 3, 7 and 16.
