CY14E256LA-SZ25XIT Cypress Semiconductor Corp, CY14E256LA-SZ25XIT Datasheet - Page 3

• Manufacturer Part Number: CY14E256LA-SZ25XIT
• Description: CY14E256LA-SZ25XIT
• Manufacturer: Cypress Semiconductor Corp

Specifications of CY14E256LA-SZ25XIT

• Format - Memory: RAM
• Memory Type: NVSRAM (Non-Volatile SRAM)
• Memory Size: 256K (32K x 8)
• Speed: 25ns
• Interface: Parallel
• Voltage - Supply: 4.5 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 32-SOIC (7.5mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Critical Considerations
The impact of the differences in CY14E256LA with respect
to the CY14E256/STK14C88 in existing applications are
discussed below. Board designers are recommended to
review the detailed datasheets when converting to the new
part.
DC Parameters
I
and hence power supply design in applications with
CY14E256L/STK14C88 would require no changes when
replacing the nvSRAM with the CY14E256LA in spite of the
higher values in the lower speed / higher standby current.
The critical parameter to consider is the V
V
While most of the differences do not impact the application,
the difference in V
converting from the older rev parts. V
which provides the required charge for AutoStore to
complete NV store of the SRAM data during power down.
The required capacitor range is different in the two parts.
Table 6. V
Therefore, any existing application using a capacitor value
outside the overlapping range for the capacitor values needs
to consider the impact of capacitor dimensions while
changing to the new capacitor. Note: The capacitor range is
the absolute value of the capacitor, net of tolerence.
AC Switching Parameters
There are a few minor differences in switching parameters
between the CY14E256LA and the CY14B256L/STK14C88
as listed in the
impact most applications. For replacing 35ns speed parts,
choose the 25ns speed parts as replacement (since 35ns
speed grade is not available in the CY14E256LA).
AutoStore / Power Up RECALL Parameters
October 5, 2009
CC1
Parameter
Software Controlled STORE/RECALL cycle Parameters
t
t
Hardware STORE cycle Parameters
t
t
HA
RECALL
HLBL
DHSB
CAP
Description
(Average current at full speed) is lower in CY14E256LA
V
CAP
CAP
Address Hold Time
STORE Cycle Duration
latch not set
Comparison
Table
LOW to STORE Busy
To Output Active Time when write
54uF to 260 uF
CAP
CY14E256L/
5. However, these differences do not
STK14C88
is a critical consideration while
Description
CAP
CAP
61uF to 180 uF
CY14E256LA
is the capacitor
.
Document No. 001-55663 Rev. **
Speed
t
The
CY14E256LA compared to the STK14C88 because of
architecture differences.
Table 7. t
This difference is not likely to affect applications since the
initialization of the controller on the board happens at the
same time. However, this should be taken into consideration
when replacing the STK14C88 with CY14E256LA.
Software Controlled STORE/RECALL Cycle Parameters
The Software cycle parameter t
CY14E256LA as described below. The software address
sequences are identical to that in the old rev part.
t
Software RECALL time (t
Table 8. t
This difference could require firmware change in the
application to increase the wait state when software
RECALL is initiated.
Software Sequence
The CY14E256LA has been designed to be compatible with
the CY14E256L/STK14C88 in the software sequence
modes. Hence, the same Software STORE and RECALL
address sequences in CY14E256L/STK14C88 works in
CY14E256LA, requiring no firmware change.
Hardware STORE cycle Parameters
The Hardware STORE parameters are much improved in
the CY14E256LA. The improvements are listed under the
following section on
will be required in applications.
HRECALL
RECALL
Min
Description
Description
20
t
t
HRECALL
CY14E256L/
Not specified
RECALL
power
STK14C88
HRECALL
RECALL
up
Comparison
Max
300
20
Comparison
RECALL is much
Details of
CY14E256L/
CY14E256L/
STK14C88
STK14C88
550 us
RECALL
20 us
Min
) is higher in CY14E256LA.
0
Improvement. No changes
CY14E256LA
RECALL
25 (t
different
CY14E256LA
CY14E256LA
Max
200
is different in
25
DELAY
200 us
20 ms
)
AN55663
in
Unit
ns
us
ns
ns
the
3
[+] Feedback