©2001 Silicon Storage Technology, Inc.

S71077-04-000

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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.

Data Sheet

4 Mbit (512K x8) SuperFlash EEPROM

SST28SF040A / SST28VF040A

FEATURES:

•

Single Voltage Read and Write Operations

– 5.0V-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

– 5.0V-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 14mm and 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 reprogrammable nonvolatile mass storage of pro-

gram, configuration, or data memory. For all system appli-

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.

SST28SF040A / SST28VF040A5.0 & 2.7 4Mb (x8) Byte-Program, Small Erase Sector flash memories