ad5231 Analog Devices, Inc., ad5231 Datasheet - Page 22

• Manufacturer Part Number: ad5231
• Description: Nonvolatile Memory, 1024-position Digital Potentiometer
• Manufacturer: Analog Devices, Inc.

AD5231
FLASH/EEMEM RELIABILITY
The Flash/EE memory array on the AD5231 is fully qualified
for two key Flash/EE memory characteristics, namely Flash/EE
memory cycling endurance and Flash/EE memory data
retention.
Endurance quantifies the ability of the Flash/EE memory to be
cycled through many program, read, and erase cycles. In real
terms, a single endurance cycle is composed of four
independent, sequential events. These events are defined as
•
•
•
•
During reliability qualification, Flash/EE memory is cycled
from 0x000 to 0x3FF until a first fail is recorded signifying the
endurance limit of the on-chip Flash/EE memory.
As indicated in the Specifications section, the AD5231 Flash/EE
memory endurance qualification has been carried out in
accordance with JEDEC Specification A117 over the industrial
temperature range of −40°C to +85°C. The results allow the
specification of a minimum endurance figure over supply and
temperature of 100,000 cycles, with an endurance figure of
700,000 cycles being typical of operation at 25°C.
Retention quantifies the ability of the Flash/EE memory to
retain its programmed data over time. Again, the AD5231 has
been qualified in accordance with the formal JEDEC Retention
Initial page erase sequence
Read/verify sequence
Byte program sequence
Second read/verify sequence
Rev. C | Page 22 of 28
Lifetime Specification (A117) at a specific junction temperature
(T
Flash/EE memory is cycled to its specified endurance limit,
described previously, before data retention is characterized.
This means that the Flash/EE memory is guaranteed to retain
its data for its full specified retention lifetime every time the
Flash/EE memory is reprogrammed. It should also be noted
that retention lifetime, based on an activation energy of 0.6 eV,
derates with T
retained for 100 years at 55°C operation, but reduces to 15 years
at 85°C operation. Beyond these limits, the part must be
reprogrammed so that the data can be restored.
J
= 55°C). As part of this qualification procedure, the
300
250
200
150
100
50
0
40
Figure 45. Flash/EE Memory Data Retention
J
, as shown in Figure 45. For example, the data is
50
T
J
60
ANALOG DEVICES
TYPICAL PERFORMANCE
AT T
JUNCTION TEMPERATURE (°C)
J
= 55°C
70
80
90
100
110