Motor de Búsqueda de Datasheet de Componentes Electrónicos
Selected language     Spanish  ▼
Nombre de pieza

M27C256B-70XC7TR Datasheet(Hoja de datos) 9 Page - STMicroelectronics

No. de Pieza. M27C256B-70XC7TR
Descripción  256 Kbit (32Kb x 8) UV EPROM and OTP EPROM
Descarga  16 Pages
Scroll/Zoom Zoom In 100% Zoom Out
Fabricante  STMICROELECTRONICS [STMicroelectronics]
Página de inicio

 9 page
background image
Electronic Signature
The Electronic Signature (ES) mode allows the
reading out of a binary code from an EPROM that
will identify its manufacturer and type. This mode
is intended for use by programming equipment to
automatically match the device to be programmed
with its corresponding programming algorithm.
The ES mode is functional in the 25°C ± 5°C am-
bient temperature range that is required when pro-
gramming the M27C256B. To activate the ES
mode, the programming equipment must force
11.5V to 12.5V on address line A9 of the
M27C256B, with VCC = VPP = 5V. Two identifier
bytes may then be sequenced from the device out-
puts by toggling address line A0 from VIL to VIH. All
other address lines must be held at VIL during
Electronic Signature mode. Byte 0 (A0 = VIL) rep-
resents the manufacturer code and byte 1
(A0 = VIH) the device identifier code. For the ST-
Microelectronics M27C256B, these two identifier
bytes are given in Table 4 and can be read-out on
outputs Q7 to Q0.
The erasure characteristics of the M27C256B is
such that erasure begins when the cells are ex-
posed to light with wavelengths shorter than ap-
proximately 4000 Å. It should be noted that
sunlight and some type of fluorescent lamps have
wavelengths in the 3000-4000 Å range. Research
shows that constant exposure to room level fluo-
rescent lighting could erase a typical M27C256B in
about 3 years, while it would take approximately 1
week to cause erasure when exposed to direct
sunlight. If the M27C256B is to be exposed to
these types of lighting conditions for extended pe-
riods of time, it is suggested that opaque labels be
put over the M27C256B window to prevent unin-
tentional erasure. The recommended erasure pro-
cedure for the M27C256B is exposure to short
wave ultraviolet light which has wavelength
2537Å. The integrated dose (i.e. UV intensity x ex-
posure time) for erasure should be a minimum of
15 W-sec/cm2. The erasure time with this dosage
is approximately 15 to 20 minutes using an ultravi-
olet lamp with 12000 µW/cm2 power rating. The
M27C256B should be placed within 2.5 cm (1
inch) of the lamp tubes during the erasure. Some
lamps have a filter on their tubes which should be
removed before erasure.

Html Pages

1  2  3  4  5  6  7  8  9  10  11  12  13  14  15  16 

Datasheet Download

Número de Pieza relacionado

Número de PiezaDescripción de ComponentesHtml ViewFabricante
M27V256256 Kbit 32Kb x 8 Low Voltage UV EPROM and OTP EPROM 1 2 3 4 5 MoreSTMicroelectronics
M27W256256 Kbit 32Kb x 8 Low Voltage UV EPROM and OTP EPROM 1 2 3 4 5 MoreSTMicroelectronics
ST721018-BIT MCU WITH 4 TO 8K ROM/OTP/EPROM 256 BYTES RAM ADC WDG SPI AND 1 OR 2 TIMERS 1 2 3 4 5 MoreSTMicroelectronics
ST72E3318-BIT MCU WITH 8 TO 16K OTP/EPROM 256 EEPROM 384 TO 512 BYTES RAM ADC WDG SCI SPI AND 2 TIMERS 1 2 3 4 5 MoreSTMicroelectronics
M27C516512 Kbit 32Kb x16 OTP EPROM 1 2 3 4 5 MoreSTMicroelectronics
M27W512512 Kbit 64Kb x8 Low Voltage UV EPROM and OTP EPROM 1 2 3 4 5 MoreSTMicroelectronics
M27V512512 Kbit 64Kb x8 Low Voltage UV EPROM and OTP EPROM 1 2 3 4 5 MoreSTMicroelectronics
M27C512-12C1512 Kbit 64K x8 UV EPROM and OTP EPROM 1 2 3 4 5 MoreSTMicroelectronics
M27C512512 Kbit 64Kb x8 UV EPROM and OTP EPROM 1 2 3 4 5 MoreSTMicroelectronics

Enlace URL

¿ALLDATASHEET es útil para Ud.?  [ DONATE ]  

Todo acerca de Alldatasheet   |   Publicidad   |   Contáctenos   |   Política de Privacidad   |   Favorito   |   Intercambio de Enlaces   |   Lista de Fabricantes
All Rights Reserved©

Mirror Sites
English :  ,  |   Chinese :  |   German :  |   Japanese :  |   Russian :
Korean :   |   Spanish :  |   French :  |   Italian :  |   Portuguese :  |   Polish :