on the CS input is required to keep the device deselected during VCC power-up, otherwise ISB will exceed values given.
CC
2
AC Test Loads and Waveforms
CYM1831
Ω
5V
OUTPUT
INCLUDING
JIG AND
SCOPE
Equivalent to:THÉ VENIN EQUIVALENT
OUTPUT
Switching Characteristics
R1 481
OUTPUT
R2
Ω
30 pF
255
(a)(b)
Ω
167
Over the Operating Range
5V
INCLUDING
JIG AND
SCOPE
1.73V
5 pF
R1 481
Ω
R2
255
1831–3
[3]
3.0V
GND
Ω
<5ns<5ns
ALL INPUT PULSES
90%
10%
90%
10%
1831–4
1831–151831–201831–251831–301831–351831–45
ParameterDescription
READ CYCLE
t
RC
t
AA
t
OHA
t
ACS
t
DOE
t
LZOE
t
HZOE
t
LZCS
t
HZCS
WRITE CYCLE
t
WC
t
SCS
t
AW
t
HA
t
SA
t
PWE
t
SD
t
HD
t
LZWE
t
HZWE
Note:
3. Test conditions assume signal transition times of 5 ns or less, timing reference levels of 1.5V, input pulse levels of 0 to 3.0V , and output loading of the specified
I
OL/IOH
4. At any given temperature and voltage condition, t
5. t
HZCS
6. The internal write time of the memory is defined by the overlap of CS
a write by going HIGH. The data input set-up and hold timing should be referenced to the rising edge of the signal that termina tes the write.
Read Cycle Time152025303545ns
Address to Data Valid152025303545ns
Data Hold from
333333ns
Address Change
CS LOW to Data Valid152025303545ns
OE LOW to Data Valid81015202030ns
OE LOW to Low Z000000ns
OE LOW to High Z81015152020ns
CS LOW to Low Z
[4]
03333ns
0
CS HIGH to High Z
[6]
[4, 5]
6813152020ns
Write Cycle Time152025303545ns
CS LOW to Write End101520253040ns
Address Set-Up to
101520253040ns
Write End
Address Hold from
222222ns
Write End
Address Set-Up to
222222ns
Write Start
WE Pulse Width101520252530ns
Data Set-Up to Write
81215152020ns
End
Data Hold from Write
222222ns
End
WE HIGH to Low Z333333ns
WE LOW to High Z
and 30-pF load capacitance.
and t
are specified with CL = 5 pF as in part (b) of AC Test Loads and Wa vef orms. Transition is measured ±500 mV from steady-state voltage.
HZWE
[5]
07010013015020020ns
HZCS
is less than t
for any given device. These parameters are guaranteed by design and not 100% tested.
LZCS
LOW and WE LOW . Both signals must be LOW to initiate a write and either signal can terminate
UnitMin. Max. Min. Max. Min. Max. Min. Max. Min. Max. Min. Max.
3
Switching Waveforms
CYM1831
Read Cycle No. 1
ADDRESS
DATA OUT
Read Cycle No. 2
CS
OE
DATA OUT
V
CC
SUPPLY
CURRENT
[7, 8]
t
RC
t
t
OHA
AA
PREVIOUS DATA VALIDDATA VALID
[7, 9]
t
RC
t
ACS
t
DOE
t
LZOE
HIGH IMPEDANCE
t
LZCS
t
PU
DATA VALID
50%
t
HZOE
t
HZCS
t
PD
50%
1831–5
HIGH
IMPEDANCE
ICC
ISB
1831–6
Notes:
7. WE
is HIGH for read cycle.
8. Device is continuously selected, CS = VIL and OE= VIL.
9. Address valid prior to or coincident with CS
transition LOW.
4
CYM1831
Switching Waveforms
(continued)
Write Cycle No. 1 (WE Controlled)
ADDRESS
CS
WE
DATA IN
DATA
OUT
Write Cycle No. 2 (CS Controlled)
ADDRESS
CS
WE
DATA IN
OUT
DATA
[6]
t
SA
DATA UNDEFINED
[6, 10]
t
SA
DATA UNDEFINED
t
SCS
t
t
AW
AW
t
t
WC
WC
DATA VALID
t
HZWE
DATA VALID
t
HZWE
t
PWE
t
PWE
t
SD
t
SCS
t
SD
t
HA
t
HD
t
LZWE
HIGH IMPEDANCE
t
HA
t
HD
HIGH IMPEDANCE
1831–7
1831–8
Note:
10. If CS
goes HIGH simultaneously with WE HIGH, the output remains in a high-impedance state.