TI SN74ACT7807PAG

SN74ACT7807
2048 × 9
CLOCKED FIRST-IN, FIRST-OUT MEMORY
SCAS200D – JANUARY 1991 – REVISED APRIL 1998
D
D
D
D
D
D
D
Free-Running Read and Write Clocks Can
Be Asynchronous or Coincident
Read and Write Operations Synchronized
to Independent System Clocks
Input-Ready Flag Synchronized to Write
Clock
Output-Ready Flag Synchronized to Read
Clock
2048 Words by 9 Bits
Low-Power Advanced CMOS Technology
Programmable Almost-Full/Almost-Empty
Flag
D
D
D
D
D
D
Input-Ready, Output-Ready, and Half-Full
Flags
Cascadable in Word Width and/or Word
Depth
Fast Access Times of 12 ns With a 50-pF
Load
Data Rates up to 67 MHz
3-State Outputs
Package Options Include 44-Pin Plastic
Leaded Chip Carrier (FN) and 64-Pin Thin
Quad Flat (PAG, PM) Packages
description
The SN74ACT7807 is a 2048-word by 9-bit FIFO with high speed and fast access times. It processes data at
rates up to 67 MHz and access times of 12 ns in a bit-parallel format. Data outputs are noninverting with respect
to the data inputs. Expansion is easily accomplished in both word width and word depth.
The write-clock (WRTCLK) and read-clock (RDCLK) inputs should be free running and can be asynchronous
or coincident. Data is written to memory on the rising edge of WRTCLK when the write-enable (WRTEN1/DP9,
WRTEN2) inputs are high and the input-ready (IR) flag output is high. Data is read from memory on the rising
edge of RDCLK when the read-enable (RDEN1, RDEN2) and output-enable (OE) inputs are high and the
output-ready (OR) flag output is high. The first word written to memory is clocked through to the output buffer
regardless of the levels on RDEN1, RDEN2, and OE. The OR flag indicates that valid data is present on the
output buffer.
The FIFO can be reset asynchronous to WRTCLK and RDCLK. RESET must be asserted while at least four
WRTCLK and four RDCLK cycles occur to clear the synchronizing registers. Resetting the FIFO initializes the
IR, OR, and half-full (HF) flags low and the almost-full/almost-empty (AF/AE) flag high. The FIFO must be reset
upon power up.
The SN74ACT7807 is characterized for operation from 0°C to 70°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.
Copyright  1998, 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
1
SN74ACT7807
2048 × 9
CLOCKED FIRST-IN, FIRST-OUT MEMORY
SCAS200D – JANUARY 1991 – REVISED APRIL 1998
VCC
HF
AF/AE
GND
PEN
RESET
VCC
NC
OE
GND
Q0
FN PACKAGE
(TOP VIEW)
6 5
7
4 3
2 1 44 43 42 41 40
39
8
38
9
37
10
36
11
35
12
34
13
33
14
32
15
31
16
30
Q1
VCC
Q2
Q3
GND
Q4
VCC
Q5
Q6
GND
Q7
Q8
29
17
18 19 20 21 22 23 24 25 26 27 28
GND
WRTCLK
WRTEN1/DP9
WRTEN2
IR
OR
RDEN2
RDEN1
RDCLK
VCC
D0
D1
D2
GND
D3
D4
D5
VCC
D6
D7
D8
Q7
NC
Q5
Q6
GND
GND
GND
Q4
VCC
VCC
Q2
Q3
GND
Q1
VCC
VCC
PAG OR PM PACKAGE
(TOP VIEW)
64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49
NC
Q0
GND
GND
OE
NC
VCC
VCC
RESET
PEN
GND
GND
AF/AE
HF
VCC
VCC
1
48
2
47
3
46
4
45
5
44
6
43
7
42
8
41
9
40
10
39
11
38
12
37
13
36
14
35
15
34
16
33
NC
D0
D1
D2
GND
GND
D3
D4
NC
D5
VCC
VCC
D6
D7
D8
NC
17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32
NC – No internal connection
2
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• DALLAS, TEXAS 75265
NC
Q8
VCC
VCC
RDCLK
RDEN1
NC
RDEN2
OR
IR
WRTEN2
WRTEN1/DP9
WRTCLK
GND
GND
NC
SN74ACT7807
2048 × 9
CLOCKED FIRST-IN, FIRST-OUT MEMORY
SCAS200D – JANUARY 1991 – REVISED APRIL 1998
logic symbol†
RESET
WRTCLK
WRTEN1/DP9
WRTEN2
RDCLK
OE
RDEN1
1
Φ
FIFO 2048 × 9
SN74ACT7807
RESET
19
WRTCLK
20
&
IN RDY
WRTEN
21
HALF FULL
26
42
RDCLK
ALMOST FULL/EMPTY
OUT RDY
EN1
25
22
5
4
23
IR
HF
AF/AE
OR
&
RDEN
RDEN2
PEN
D0
D1
D2
D3
D4
D5
D6
D7
D8
24
2
7
PROGRAM ENABLE
0
0
40
8
39
9
37
11
36
12
Data
Data
34
1
13
32
15
31
16
29
17
28
8
8
Q0
Q1
Q2
Q3
Q4
Q5
Q6
Q7
Q8
† This symbol is in accordance with ANSI/IEEE Std 91-1984 and IEC Publication 617-12.
Pin numbers shown are for the FN package.
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
3
SN74ACT7807
2048 × 9
CLOCKED FIRST-IN, FIRST-OUT MEMORY
SCAS200D – JANUARY 1991 – REVISED APRIL 1998
functional block diagram
OE
D0–D8
Location 1
RDCLK
RDEN1
RDEN2
Synchronous
Read
Control
Location 2
Read
Pointer
2048 × 9 RAM
WRTCLK
WRTEN1/DP9
WRTEN2
Synchronous
Write
Control
Write
Pointer
Location 2047
Location 2048
Register
RESET
StatusFlag
Logic
Reset
Logic
Q0 – Q8
OR
IR
HF
PEN
AF/AE
4
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• DALLAS, TEXAS 75265
SN74ACT7807
2048 × 9
CLOCKED FIRST-IN, FIRST-OUT MEMORY
SCAS200D – JANUARY 1991 – REVISED APRIL 1998
Terminal Functions
TERMINAL
NAME
I/O
DESCRIPTION
O
Almost-full/almost-empty flag. Depth offset values can be programmed for AF/AE or the default value of 256 can
be used for both the almost-empty offset (X) and the almost-full offset (Y). AF/AE is high when memory contains
X or fewer words or (2048 – Y) or more words. AF/AE is high after reset.
D0–D8
I
Nine-bit data input port
HF
O
Half-full flag. HF is high when the FIFO memory contains 1024 or more words. HF is low after reset.
IR
O
Input-ready flag. IR is synchronized to the low-to-high transition of WRTCLK. When IR is low, the FIFO is full and
writes are disabled. IR is low during reset and goes high on the second low-to-high transition of WRTCLK after
reset.
OE
I
Output enable. When OE, RDEN1, RDEN2 and OR are high, data is read from the FIFO on a low-to-high transition
of RDCLK. When OE is low, reads are disabled and the data outputs are in the high-impedance state.
OR
O
Output-ready flag. OR is synchronized to the low-to-high transition of RDCLK. When OR is low, the FIFO is empty
and reads are disabled. Ready data is present on Q0–Q17 when OR is high. OR is low during reset and goes high
on the third low-to-high transition of RDCLK after the first word is loaded to empty memory.
PEN
I
Program enable. After reset and before the first word is written to the FIFO, the binary value on D0–D8 and DP9
is latched as an AF/AE offset value when PEN is low and WRTCLK is high.
Q0–Q8
O
Nine-bit data output port. After the first valid write to empty memory, the first word is output on Q0–Q8 on the third
rising edge of RDCLK. OR also is asserted high at this time to indicate ready data. When OR is low, the last word
read from the FIFO is present on Q0–Q8.
RDCLK
I
Read clock. RDCLK is a continuous clock and can be asynchronous or coincident to WRTCLK. A low-to-high
transition of RDCLK reads data from memory when RDEN1, RDEN2, OE, and OR are high. OR is synchronous
to the low-to-high transition of RDCLK.
RDEN1
RDEN2
I
Read enables. When RDEN1, RDEN2, OE, and OR are high, data is read from the FIFO on the low-to-high
transition of RDCLK.
RESET
I
Reset. To reset the FIFO, four low-to-high transitions of RDCLK and four low-to-high transitions of WRTCLK must
occur while RESET is low. This sets HF, IR, and OR low and AF/AE high.
WRTCLK
I
Write clock. WRTCLK is a continuous clock and can be asynchronous or coincident to RDCLK. A low-to-high
transition of WRTCLK writes data to memory when WRTEN1/DP9, WRTEN2, and IR are high. IR is synchronous
to the low-to-high transition of WRTCLK.
WRTEN1/DP9
I
Write enable/data pin 9. When WRTEN1/DP9, WRTEN2, and IR are high, data is written to the FIFO on a
low-to-high transition of WRTCLK. When programming an AF/AE offset value, WRTEN1/DP9 is used as the
most-significant data bit.
WRTEN2
I
Write enable. When WRTEN1/DP9, WRTEN2, and IR are high, data is written to the FIFO on a low-to-high
transition of WRTCLK.
AF/AE
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5
SN74ACT7807
2048 × 9
CLOCKED FIRST-IN, FIRST-OUT MEMORY
SCAS200D – JANUARY 1991 – REVISED APRIL 1998
offset values for AF/AE
The AF/AE flag has two programmable limits: the almost-empty offset value (X) and the almost-full offset
value (Y). They can be programmed after the FIFO is reset and before the first word is written to memory. If the
offsets are not programmed, the default values of X = Y = 256 are used. The AF/AE flag is high when the FIFO
contains X or fewer words or (2048 – Y) or more words.
Program enable (PEN) should be held high throughout the reset cycle. PEN can be brought low only when IR
is high and WRTCLK is low. On the following low-to-high transition of WRTCLK, the binary value on D0–D8 and
WRTEN1/DP9 is stored as the almost-empty offset value (X) and the almost-full offset value (Y). Holding PEN
low for another low-to-high transition of WRTCLK reprograms Y to the binary value on D0–D8 and
WRTEN1/DP9 at the time of the second WRTCLK low-to-high transition. While the offsets are programmed,
data is not written to the FIFO memory, regardless of the state of the write enables (WRTEN1/DP9, WRTEN2).
A maximum value of 1023 can be programmed for either X or Y (see Figure 1). To use the default values of
X = Y = 256, PEN must be held high.
RESET
WRTCLK
3
4
PEN
D0–D8
ÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎ
X and Y
Y
ÏÏÏÏÏÏÏÏ
ÏÏÏÏÏÏÏÏ
ÎÎÎÎÎ
ÎÎÎÎÎ
Word 1
IR
ÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎ
ÏÏÏÏÏÏÏÏÏÏÏÏÏÏÏÏÏÏ
ÏÏÏÏÏÏÏÏÏÏÏÏÏÏÏÏÏÏ
ÏÏÏÏÏÏÏÏÏÏÏÏÏÏÏÏÏÏ
X and Y
MSB
WRTEN1/DP9
YMSB
WRTEN2
Figure 1. Programming X and Y Separately
6
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• DALLAS, TEXAS 75265
SN74ACT7807
2048 × 9
CLOCKED FIRST-IN, FIRST-OUT MEMORY
SCAS200D – JANUARY 1991 – REVISED APRIL 1998
RESET
1
0
PEN
1
WRTCLK
2
3
4
1
2
ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ
WRTEN1/DP9
Don’t Care
WRTEN2
Don’t Care
Don’t Care
D0–D8
1
RDCLK
2
3
4
ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉ
ÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎ
ÎÎÎÎÎÎ
ÎÎÎÎÎÎ
ÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎ
RDEN1
Don’t Care
RDEN2
Don’t Care
1
0
OE
Q0–Q8
Invalid
OR
Don’t Care
AF/AE
Don’t Care
HF
Don’t Care
IR
Don’t Care
Define the AF/AE Flag Using the
Default Value of X = Y = 256
Figure 2. Reset Cycle
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7
SN74ACT7807
2048 × 9
CLOCKED FIRST-IN, FIRST-OUT MEMORY
SCAS200D – JANUARY 1991 – REVISED APRIL 1998
1
RESET
0
1
PEN
0
WRTCLK
1
0
WRTEN1/DP9
WRTEN2
ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ
D0–D8
RDCLK
W1
W2
W3
W4
1
2
3
W(X+2)
W1025
W(2049–Y)
W2049
1
0
RDEN1
RDEN2
1
0
OE
ÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉ
Q0–Q8
Invalid
W1
OR
AF/AE
HF
IR
Figure 3. Write Cycle
8
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• DALLAS, TEXAS 75265
SN74ACT7807
2048 × 9
CLOCKED FIRST-IN, FIRST-OUT MEMORY
SCAS200D – JANUARY 1991 – REVISED APRIL 1998
1
0
RESET
1
PEN
0
WRTCLK
1
2
WRTEN1/
DP9
WRTEN2
ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ
D0–D8
W2049
RDCLK
RDEN1
RDEN2
1
OE
ÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉ
Q0–Q8
W1
W2
W3
W(Y+1)
W(Y+2)
W1025
W1026 W(2048–X)
W(2049–X) W2048
0
W2049
OR
AF/AE
HF
IR
Figure 4. Read Cycle
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9
SN74ACT7807
2048 × 9
CLOCKED FIRST-IN, FIRST-OUT MEMORY
SCAS200D – JANUARY 1991 – REVISED APRIL 1998
absolute maximum ratings over operating free-air temperature range (unless otherwise noted)†
Supply voltage range, VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.5 V to 7 V
Input voltage range, VI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.5 V to 7 V
Voltage range applied to a disabled 3-state output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.5 V to 5.5 V
Package thermal impedance, θJA (see Note 1): FN package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46°C/W
PAG package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58°C/W
PM package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67°C/W
Storage temperature range, Tstg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –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.
NOTE 1: The package thermal impedance is calculated in accordance with JESD 51.
recommended operating conditions
’ACT7807-15
VCC
VIH
Supply voltage
VIL
IOH
Low-level input voltage
IOL
Low level output current
Low-level
TA
Operating free-air temperature
’ACT7807-25
’ACT7807-40
MAX
MIN
MAX
MIN
MAX
MIN
MAX
4.5
5.5
4.5
5.5
4.5
5.5
4.5
5.5
High-level input voltage
High-level output current
’ACT7807-20
MIN
2
2
2
2
UNIT
V
V
0.8
0.8
0.8
0.8
V
Q outputs, flags
–8
–8
–8
–8
mA
Q outputs
16
16
16
16
8
8
8
8
Flags
0
70
0
70
0
70
0
70
mA
°C
electrical characteristics over recommended operating free-air temperature range (unless
otherwise noted)
PARAMETER
VOH
VOL
Flags
Q outputs
II
IOZ
ICC
∆ICC§
Ci
Co
WRTEN1/DP9
Other inputs
TEST CONDITIONS
TYP‡
MAX
2.4
UNIT
VCC = 4.5 V,
VCC = 4.5 V,
IOH = –8 mA
IOL = 8 mA
V
VCC = 4.5 V,
VCC = 5.5 V,
IOL = 16 mA
VI = VCC or 0
0.5
±5
µA
VCC = 5.5 V,
VCC = 5.5 V,
VO = VCC or 0
VI = VCC – 0.2 V or 0
±5
µA
400
µA
0.5
2
Other inputs at VCC or GND
V
5V
VCC = 5
5.5
V,
4V
One input at 3
3.4
V,
VI = 0,
VO = 0,
f = 1 MHz
4
pF
f = 1 MHz
8
pF
‡ All typical values are at VCC = 5 V, TA = 25°C.
§ This is the supply current for each input that is at one of the specified TTL voltage levels rather 0 V or VCC.
10
MIN
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
1
mA
SN74ACT7807
2048 × 9
CLOCKED FIRST-IN, FIRST-OUT MEMORY
SCAS200D – JANUARY 1991 – REVISED APRIL 1998
timing requirements over recommended operating free-air temperature range (unless otherwise
noted) (see Figures 1 through 5)
’ACT7807-15
MIN
fclock
tw
Clock frequency
Pulse duration
tsu
Setup time
th
Hold time
MAX
’ACT7807-20
MIN
MAX
67
’ACT7807-25
MIN
50
MAX
’ACT7807-40
MIN
40
MAX
25
WRTCLK high or low
6
8
9
13
RDCLK high or low
6
8
9
13
PEN low
6
9
9
13
D0–D8 before WRTCLK↑
4
5
5
5
WRTEN1, WRTEN2
before WRTCLK↑
4
5
5
5
OE, RDEN1, RDEN2
before RDCLK↑
5
6
6
6.5
Reset: RESET low before
first WRTCLK↑ and RDCLK↑†
7
8
8
8
PEN before WRTCLK↑
4
5
5
5
D0–D8 after WRTCLK↑
0
0
0
0
WRTEN1, WRTEN2
after WRTCLK↑
0
0
0
0
OE, RDEN1, RDEN2
after RDCLK↑
0
0
0
0
Reset: RESET low after
fourth WRTCLK↑ and RDCLK↑†
5
5
5
5
PEN high after WRTCLK↓
0
0
0
0
PEN low after WRTCLK↑
3
3
3
3
UNIT
MHz
ns
ns
ns
† To permit the clock pulse to be utilized for reset purposes
switching characteristics over recommended ranges of supply voltage and operating free-air
temperature, CL = 50 pF (unless otherwise noted) (see Figure 5)
PARAMETER
FROM
(INPUT)
fmax
WRTCLK or
RDCLK
tpd
tpd§
tpd
d
TO
(OUTPUT)
RDCLK↑
Any Q
’ACT7807-15
TYP‡
MAX
’ACT7807-20
MIN
MIN
67
50
3
9
MAX
’ACT7807-25
MIN
MAX
40
’ACT7807-40
MIN
MAX
25
MHz
12
3
13
3
18
3
25
9
1
12
1
14
1
16
RDCLK↑
Any Q
WRTCLK↑
IR
1
RDCLK↑
OR
1
9
2
12
2
14
2
16
2
16
2
20
2
25
2
30
2
17
2
20
2
25
2
30
WRTCLK↑
RDCLK↑
8
AF/AE
UNIT
ns
ns
ns
tPLH
tPHL
WRTCLK↑
HF
2
19
2
21
2
23
2
25
ns
RDCLK↑
HF
2
16
2
18
2
20
2
22
ns
tPLH
RESET low
AF/AE
1
12
1
18
1
22
1
24
ns
tPHL
RESET low
HF
2
12
2
18
2
22
2
24
ns
OE
Any Q
2
10
2
13
2
15
2
18
ns
OE
Any Q
1
11
1
13
1
15
1
18
ns
ten
tdis
‡ All typical values are at VCC = 5 V, TA = 25°C.
§ This parameter is measured with CL = 30 pF (see Figure 6).
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
11
SN74ACT7807
2048 × 9
CLOCKED FIRST-IN, FIRST-OUT MEMORY
SCAS200D – JANUARY 1991 – REVISED APRIL 1998
operating characteristics, VCC = 5 V, TA = 25°C
PARAMETER
Cpd
TEST CONDITIONS
Power dissipation capacitance per FIFO channel
Outputs enabled
CL = 50 pF,
TYP
f = 5 MHz
91
UNIT
pF
PARAMETER MEASUREMENT INFORMATION
7V
PARAMETER
S1
500 Ω
ten
From Output
Under Test
Test
Point
CL = 50 pF
(see Note A)
tdis
500 Ω
tpd
S1
tPZH
tPZL
tPHZ
tPLZ
tPLH
tPHL
Open
Closed
Open
Closed
Open
Open
tw
LOAD CIRCUIT
3V
Input
0V
1.5 V
0V
tsu
VOLTAGE WAVEFORMS
PULSE DURATION
th
3V
Data
Input
1.5 V
1.5 V
0V
3V
Output
Control
tPZL
3V
1.5 V
1.5 V
1.5 V
0V
tPLH
1.5 V
1.5 V
tPZH
1.5 V
VOL
Output
Waveform 2
S1 at Open
VOLTAGE WAVEFORMS
PROPAGATION DELAY TIMES
VOL + 0.3 V
VOL
tPHZ
1.5 V
VOH
VOH – 0.3 V
≈0V
VOLTAGE WAVEFORMS
ENABLE AND DISABLE TIMES
NOTE A: CL includes probe and jig capacitance.
Figure 5. Load Circuit and Voltage Waveforms
POST OFFICE BOX 655303
tPLZ
≈ 3.5 V
Output
Waveform 1
S1 at 7 V
tPHL
VOH
12
1.5 V
0V
VOLTAGE WAVEFORMS
SETUP AND HOLD TIMES
Output
1.5 V
3V
Timing
Input
Input
1.5 V
• DALLAS, TEXAS 75265
SN74ACT7807
2048 × 9
CLOCKED FIRST-IN, FIRST-OUT MEMORY
SCAS200D – JANUARY 1991 – REVISED APRIL 1998
TYPICAL CHARACTERISTICS
PROPAGATION DELAY TIME
vs
LOAD CAPACITANCE
ACTIVE ICC
vs
FREQUENCY
200
VCC = 5 V
RL = 500 Ω
TA = 25°C
TA = 25°C
180
VCC = 5.5 V
160
I CC(f) – Active I CC – mA
typ + 6
typ + 4
typ + 2
140
VCC = 5 V
120
100
80
VCC = 4.5 V
60
typ
40
20
typ – 2
0
0
50
100
150
200
250
0
300
10
20
CL – Load Capacitance – pF
30
40
50
60
70
f – Frequency – MHz
Figure 7
Figure 6
6
VCC = 4.5 V
VCC = 5 V
VCC = 5.5 V
5
TA = 25°
I CC(I) – Idle ICC – mA
t pd – Propagation Delay Time – ns
typ + 8
4
3
Slope = 0.07
2
1
0
0
10
20
30
40
50
60
70
f – Frequency – MHz
Figure 8. SN74ACT7807 Idle ICC With WRTCLK Switching,
Other Inputs at 0 or VCC – 0.2 V and Outputs Disconnected
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
13
SN74ACT7807
2048 × 9
CLOCKED FIRST-IN, FIRST-OUT MEMORY
SCAS200D – JANUARY 1991 – REVISED APRIL 1998
APPLICATION INFORMATION
CLOCK
SN74ACT7807
RDCLK
SN74ACT7807
RDCLK
WRTCLK
WRTCLK
OR
WRTEN1
WRTEN1/DP9
WRTEN2
WRTEN2
RDEN1
IR
RDEN2
IR
OE
D0–D8
D0–D8
WRTCLK
RDEN1
RDEN1
WRTEN2
RDEN2
RDEN2
IR
5V
Q0–Q8
RDCLK
WRTEN1/DP9
D0–D8
OR
OR
OE
OE
Q0–Q8
Q0–Q8
Figure 9. Word-Depth Expansion: 4096 × 9 Bits
WRTCLK
WRTEN
SN74ACT7807
RDCLK
WRTCLK
WRTEN1/DP9
RDEN1
WRTEN2
RDEN2
IR
RDEN
OR
OE
D9–D17
RDCLK
Q0–Q8
D0–D8
OE
Q9–Q17
OR
IR
SN74ACT7807
RDCLK
WRTCLK
WRTEN1/DP9
RDEN1
WRTEN2
RDEN2
IR
OR
OE
D0–D8
D0–D8
Q0–Q8
Figure 10. Word-Width Expansion: 2048 × 18 Bits
14
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
Q0–Q8
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