EPROM

What is EPROM?
EPROM stands for erasable programmable read only memory and is a type of solid state memory chip that retains its memory contents without the help of a power supply.
The basic transistor device in an EPROM is different from the normal MOS transistor. A floating gate avalanche injection MOS transistor is used. There are two gates to this MOS transistor. One is a floating gate, meaning that it has no electrical connection to that gate.
Types of solid state memory available with different desirable characteristics:
ROM
Read Only Memory, non-volatile (memory contents are retained even without the help of a power supply), are low power and high density.
RAM
Random Access Memory is volatile.
PROM
Programmable ROM allows you to write your own content or program. It cannot be erased so you can only program it once.
EPROM
You can erase whatever you have programmed and can reprogram it thus allowing it to be reused. It can be erased with ultra violet (UV) light which basically means that you have to take the chip out from the circuit and expose the memory chip to UV lights. These memory chips come with a particular package which enables this to happen. Standard room lighting cannot be used to erase the chip as it does not have enough UV light, however bright sunlight can cause erasure therefore this is why the window is protected with a label. There is a glass window on top which you can expose these memory cells to UV light. Once this happens the electrons which are in the floating gate, get excited because of the high energy they acquire and they overcome the silicon dioxide barrier and move over to the silicon substrate or the control gate and once they do this you are reducing the threshold voltage. This can take up to 30 minutes in which you have to expose it to UV light, after which the electrons move out from the floating gate and then it is ready for reprogramming.
Disadvantages of EPROM is that it takes time to erase the entire content. You don’t have control over which bits you want erased.
Differences between EPROM and EEPROM
EEPROM (electrically erasable programmable ROM) can be erased electrically and can be reprogrammed. The device it uses is called FLOTOX (Floating Gate Tunnelling Oxide) MOS. It is more flexible than EPROM, for example you can erase a single bit of memory internally at a time without removing the chip. There are also two transistors per cell instead of one so the density of an EEPROM is slightly less compared to the normal EPROM.

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Description Prix Memory Size Organisation Interface Type Maximum Random Access Time Programming Voltage Reprogramming Technique In System Programmability Mounting Type Package Type Pin Count Dimensions Height Length Maximum Operating Supply Voltage
N° de stock RS 127-6561
Référence fabricantAT27C4096-90JU
MarqueMicrochip
5,72 €
Each
Unité
4Mbit 256K x 16 bit - 90ns - OTP - Through Hole PLCC 44 16.66 x 16.66 x 4.06mm 4.06mm 16.66mm -
N° de stock RS 127-6552
Référence fabricantAT27C1024-45PU
MarqueMicrochip
3,07 €
Each (In a Pack of 2)
Unité
1Mbit 64K x 16 bit - 45ns - OTP - Through Hole PDIP 40 52.57 x 13.97 x 4.44mm 4.44mm 52.57mm -
N° de stock RS 127-6545
Référence fabricantAT27C040-70JU
MarqueMicrochip
4,105 €
Each (In a Pack of 2)
Unité
4Mbit 512K x 8 bit - 70ns - OTP - Through Hole PLCC 32 14.04 x 11.5 x 3.17mm 3.17mm 14.04mm -
N° de stock RS 127-6559
Référence fabricantAT27C256R-70PU
MarqueMicrochip
1,82 €
Each (In a Pack of 5)
Unité
256kbit 32K x 8 bit - 70ns - OTP - Through Hole PDIP 28 37.33 x 13.97 x 4.44mm 4.44mm 37.33mm -
N° de stock RS 127-6551
Référence fabricantAT27C1024-45JU
MarqueMicrochip
2,82 €
Each (In a Pack of 2)
Unité
1Mbit 64K x 16 bit - 45ns - OTP - Through Hole PLCC 44 16.66 x 16.66 x 4.06mm 4.06mm 16.66mm -
N° de stock RS 127-6558
Référence fabricantAT27C256R-70JU
MarqueMicrochip
1,622 €
Each (In a Pack of 5)
Unité
256kbit 32K x 8 bit - 70ns - OTP - Through Hole PLCC 32 14.04 x 11.5 x 3.17mm 3.17mm 14.04mm -
N° de stock RS 190-6082
Référence fabricantDS2502R+T&R
1,047 €
Each (On a Reel of 3000)
Unité
1kbit - 1-Wire - 12 V @ 10 mA - - Surface Mount SOT-23 3 3.04 x 1.4 x 1.02mm 1.02mm 3.04mm 6 V
N° de stock RS 127-4048
Référence fabricantAT27C010-70JU
MarqueMicrochip
2,232 €
Each (In a Pack of 5)
Unité
1Mbit 128K x 8 bit - 70ns - OTP - Through Hole PLCC 32 14.04 x 11.5 x 3.17mm 3.17mm 14.04mm -
N° de stock RS 137-698
Référence fabricantDS1982-F5+
3,03 €
Each
Unité
- - - - - - - - F5 MicroCan 2 17.35 (Dia.) x 5.89mm 5.89mm - -
N° de stock RS 127-6566
Référence fabricantAT27C512R-70PU
MarqueMicrochip
1,912 €
Each (In a Pack of 5)
Unité
512kbit 64K x 8 bit - 70ns - OTP - Through Hole PDIP 28 37.33 x 13.97 x 4.44mm 4.44mm 37.33mm -
N° de stock RS 177-1855
Référence fabricantAT27LV512A-90JU
MarqueMicrochip
2,01 €
Each (In a Pack of 5)
Unité
512kbit 64K x 8 bit Parallel 90ns - OTP - Surface Mount PLCC 32 14.04 x 11.5 x 3.17mm 3.17mm 14.04mm 3.6 (Low Voltage) V, 5 (Standard) V
N° de stock RS 127-6546
Référence fabricantAT27C040-70PU
MarqueMicrochip
4,355 €
Each (In a Pack of 2)
Unité
4Mbit 512K x 8 bit - 70ns - OTP - Through Hole PDIP 32 42.29 x 13.97 x 4.44mm 4.44mm 42.29mm -
N° de stock RS 178-4839
Référence fabricantAT27C020-55PU
MarqueMicrochip
2,983 €
Each (In a Tube of 12)
Unité
2Mbit 256K x 8 bit - 55ns - OTP - Through Hole PDIP 32 42.29 x 13.97 x 4.44mm 4.44mm 42.29mm -
N° de stock RS 127-6547
Référence fabricantAT27C040-90JU
MarqueMicrochip
4,075 €
Each (In a Pack of 2)
Unité
4Mbit 512K x 8 bit - 90ns - OTP - Through Hole PLCC 32 14.04 x 11.5 x 3.17mm 3.17mm 14.04mm -
N° de stock RS 127-6548
Référence fabricantAT27C040-90PU
MarqueMicrochip
4,32 €
Each (In a Pack of 2)
Unité
4Mbit 512K x 8 bit - 90ns - OTP - Through Hole PDIP 32 42.29 x 13.97 x 4.44mm 4.44mm 42.29mm -
N° de stock RS 172-9358
Référence fabricantDS1982-F5+
2,527 €
Each (In a Tube of 100)
Unité
- - - - - - - - F5 MicroCan 2 17.35 (Dia.) x 5.89mm 5.89mm - -
N° de stock RS 127-4062
Référence fabricantAT27C020-90PU
MarqueMicrochip
3,025 €
Each (In a Pack of 2)
Unité
- - - - - - - - - - - - - -
N° de stock RS 177-1739
Référence fabricantAT27LV010A-70JU
MarqueMicrochip
2,45 €
Each (In a Pack of 5)
Unité
1Mbit 128K x 8 bit Parallel 70ns - OTP - Surface Mount PLCC 32 14.04 x 11.5 x 3.17mm 3.17mm 14.04mm 3.6 (Low Voltage) V, 5 (Standard) V
N° de stock RS 190-6989
Référence fabricantDS2502R+T&R
1,654 €
Each (In a Pack of 5)
Unité
1kbit - 1-Wire - 12 V @ 10 mA - - Surface Mount SOT-23 3 3.04 x 1.4 x 1.02mm 1.02mm 3.04mm 6 V
N° de stock RS 786-0818
Référence fabricantDS2502P+
2,112 €
Each (In a Pack of 5)
Unité
1kbit - - - - - - Surface Mount TSOC 6 4 x 3.89 x 1.5mm 1.5mm - -