Cypress CY7C144 Computer Hardware User Manual


 
CY7C145, CY7C144
Document #: 38-06034 Rev. *D Page 6 of 21
Figure 4. AC Test Loads and Waveforms
3.0V
GND
90%
90%
10%
3ns
3 ns
10%
ALL INPUT PULSES
(a) Normal Load (Load1)
5V
OUTPUT
C= 30
pF
V
TH
= 1.4V
OUTPUT
C = 30pF
(b) Th évenin Equivalent (Load 1)
(c) Three-State Delay (Load 3)
C= 30pF
OUTPUT
Load (Load 2)
5V
OUTPUT
C= 5pF
R1 = 893Ω
R2 = 347Ω
R
TH
= 250Ω
R1 = 893Ω
R = 347Ω
Switching Characteristics Over the Operating Range
[9]
Parameter Description
7C144-15
7C145-15
7C144-25
7C145-25
7C144-35
7C145-35
7C144-55
7C145-55
Unit
Min Max Min Max Min Max Min Max
READ CYCLE
t
RC
Read Cycle Time 15 25 35 55 ns
t
AA
Address to Data Valid 15 25 35 55 ns
t
OHA
Output Hold From Address
Change
3333ns
t
ACE
CE LOW to Data Valid 15 25 35 55 ns
t
DOE
OE LOW to Data Valid 10 15 20 25 ns
t
LZOE
[10, 11,12]
OE Low to Low Z 3 3 3 3 ns
t
HZOE
[10, 11,12]
OE HIGH to High Z 10 15 20 25 ns
t
LZCE
[10, 11,12]
CE LOW to Low Z 3 3 3 3 ns
t
HZCE
[10, 11,12]
CE HIGH to High Z 10 15 20 25 ns
t
PU
[12]
CE LOW to Power-Up 0 0 0 0 ns
t
PD
[12]
CE HIGH to Power-Down 15 25 35 55 ns
WRITE CYCLE
t
WC
Write Cycle Time 15 25 35 55 ns
t
SCE
CE LOW to Write End 12 20 30 45 ns
t
AW
Address Set-Up to Write End 12 20 30 45 ns
t
HA
Address Hold From Write End 2 2 2 2 ns
t
SA
Address Set-Up to Write Start 0 0 0 0 ns
t
PWE
Write Pulse Width 12 20 25 40 ns
Notes
9. Test conditions assume signal transition time of 3 ns or less, timing reference levels of 1.5V, input pulse levels of 0 to 3.0V, and output loading of the specified
I
OI
/I
OH
and 30-pF load capacitance.
10.At any given temperature and voltage condition for any given device, t
HZCE
is less than t
LZCE
and t
HZOE
is less than t
LZOE
.
11. Test conditions used are Load 3.
12.This parameter is guaranteed but not tested.
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