4 Mbit (512K x8) SuperFlash EEPROM
SST28SF040A / SST28VF040A
SST28SF / VF040A4Mb (x8)
Byte-Program, Small Erase Sector flash memories
Data Sheet
FEATURES:
• Single Voltage Read and Write Operations
– 4.5-5.5V-only for SST28SF040A
– 2.7-3.6V for SST28VF040A
• Superior Reliability
– Endurance: 100,000 Cycles (typical)
– Greater than 100 years Data Retention
• Memory Organization: 512K x8
• Sector-Erase Capability: 256 Bytes per Sector
• Low Power Consumption
– Active Current: 15 mA (typical) for 5.0V and
10 mA (typical) for 2.7-3.6V
– Standby Current: 5 µA (typical)
• Fast Sector-Erase/Byte-Program Operation
– Byte-Program Time: 35 µs (typical)
– Sector-Erase Time: 2 ms (typical)
– Complete Memory Rewrite: 20 sec (typical)
• Fast Read Access Time
– 4.5-5.5V-only operation: 90 and 120 ns
– 2.7-3.6V operation: 150 and 200 ns
• Latched Address and Data
• Hardware and Software Data Protection
– 7-Read-Cycle-Sequence Software Data
Protection
• End-of-Write Detection
– Toggle Bit
– Data# Polling
• TTL I/O Compatibility
• JEDEC Standard
– Flash EEPROM Pinouts
• Packages Available
– 32-lead PLCC
– 32-lead TSOP (8mm x 20mm)
– 32-pin PDIP
PRODUCT DESCRIPTION
The SST28SF/VF040A are 512K x8 bit CMOS Sector-
Erase, Byte-Program EEPROMs. The SST28SF/VF040A
are manufactured using SST’s proprietary, high perfor-
mance CMOS SuperFlash EEPROM Technology. The
split-gate cell design and thick-oxide tunneling injector
attain better reliability and manufacturability compared with
alternative approaches. The SST28SF/VF040A erase and
program with a single power supply. The SST28SF/
VF040A conform to JEDEC standard pinouts for byte wide
memories and are compatible with existing industry stan-
dard flash EEPROM pinouts.
Featuring high performance programming, the SST28SF/
VF040A typically Byte-Program in 35 µs. The SST28SF/
VF040A typically Sector-Erase in 2 ms. Both Program and
Erase times can be optimized using interface features such
as Toggle bit or Data# Polling to indicate the completion of
the Write cycle. To protect against an inadvertent write, the
SST28SF/VF040A have on chip hardware and Software
Data Protection schemes. Designed, manufactured, and
tested for a wide spectrum of applications, the SST28SF/
VF040A are offered with a guaranteed sector endurance of
10,000 cycles. Data retention is rated greater than 100
years.
The SST28SF/VF040A are best suited for applications that
require re-programmable nonvolatile mass storage of pro-
gram, configuration, or data memory. For all system appli-
©2003 Silicon Storage Technology, Inc.
S71077-05-000 3/03
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cations, the SST28SF/VF040A significantly improve
performance and reliability, while lowering power consump-
tion when compared with floppy diskettes or EPROM
approaches. Flash EEPROM technology makes possible
convenient and economical updating of codes and control
programs on-line. The SST28SF/VF040A improve flexibil-
ity, while lowering the cost of program and configuration
storage application.
The functional block diagram shows the functional blocks of
the SST28SF/VF040A. Figures 1, 2, and 3 show the pin
assignments for the 32-lead PLCC, 32-lead TSOP and 32-
,
pin PDIP packages. Pin descriptions and operation modes
are described in Tables 2 through 5.
Device Operation
Commands are used to initiate the memory operation func-
tions of the device. Commands are written to the device
using standard microprocessor write sequences. A com-
mand is written by asserting WE# low while keeping CE#
low. The address bus is latched on the falling edge of WE#
or CE#, whichever occurs last. The data bus is latched on
the rising edge of WE# or CE#, whichever occurs first.
Note, during the Software Data Protection sequence the
addresses are latched on the rising edge of OE# or CE#,
whichever occurs first.
The SST logo and SuperFlash are registered trademarks of Silicon Storage Technology, Inc.
SSF is a trademark of Silicon Storage Technology, Inc.
These specifications are subject to change without notice.
SST [ SILICON STORAGE TECHNOLOGY, INC ]
