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:ROMRead Only Memory, non-volatile (memory contents are retained even without the help of a power supply), are low power and high density.RAMRandom Access Memory is volatile.PROMProgrammable ROM allows you to write your own content or program. It cannot be erased so you can only program it once. EPROMYou 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 dont have control over which bits you want erased.Differences between EPROM and EEPROMEEPROM (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 Price 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
RS Stock No. 540-4845
Mfr. Part No.DS2505+
£2.29
Each
Units
16kbit - - - - - - Through Hole TO-92 3 - 4.95mm - -
RS Stock No. 169-8319
Mfr. Part No.DS2505+
£1.931
Each (In a Tube of 10)
Units
16kbit - - - - - - Through Hole TO-92 3 - 4.95mm - -
RS Stock No. 137-519
Mfr. Part No.DS1982-F3+
£2.60
Each
Units
- - - - - - - - F3 MicroCan 2 17.36 (Dia.) x 3.1mm 3.1mm - -
RS Stock No. 540-4839
Mfr. Part No.DS2502+
£1.77
Each
Units
1kbit - - - - - - Through Hole TO-92 3 4.95 (Dia.) x 3.94mm 3.94mm - -
RS Stock No. 169-8318
Mfr. Part No.DS2502+
£1.518
Each (In a Tube of 10)
Units
1kbit - - - - - - Through Hole TO-92 3 4.95 (Dia.) x 3.94mm 3.94mm - -
RS Stock No. 103-9913
Mfr. Part No.DS2502P-E48+
£1.823
Each (In a Tube of 120)
Units
1024bit - - - - - - Surface Mount TSOC 6 4 x 3.89 x 1.5mm 1.5mm - -
RS Stock No. 732-7563
Mfr. Part No.DS2502P-E48+
£2.31
Each
Units
1024bit - - - - - - Surface Mount TSOC 6 4 x 3.89 x 1.5mm 1.5mm - -
RS Stock No. 172-9358
Mfr. Part No.DS1982-F5+
£2.113
Each (In a Tube of 100)
Units
- - - - - - - - F5 MicroCan 2 17.35 (Dia.) x 5.89mm 5.89mm - -
RS Stock No. 137-698
Mfr. Part No.DS1982-F5+
£2.74
Each
Units
- - - - - - - - F5 MicroCan 2 17.35 (Dia.) x 5.89mm 5.89mm - -
RS Stock No. 786-0818
Mfr. Part No.DS2502P+
£1.078
Each (In a Pack of 5)
Units
1kbit - - - - - - Surface Mount TSOC 6 4 x 3.89 x 1.5mm 1.5mm - -
RS Stock No. 146-1071
Mfr. Part No.DS2502P+
£1.059
Each (In a Tube of 120)
Units
1kbit - - - - - - Surface Mount TSOC 6 4 x 3.89 x 1.5mm 1.5mm - -
New
RS Stock No. 190-6989
Mfr. Part No.DS2502R+T&R
£1.456
Each (In a Pack of 5)
Units
- - - - - - - - - - - - - -
New
RS Stock No. 192-1254
Mfr. Part No.DS1982-F3+
£1.974
Each (In a Bag of 100)
Units
- - - - - - - - F3 MicroCan 2 17.36 (Dia.) x 3.1mm 3.1mm - -
New
RS Stock No. 192-1255
Mfr. Part No.DS2502S+
£1.554
Each (In a Tube of 100)
Units
1kbit 1K x 1 bit 1-Wire 120µs 11.5V OTP In System Surface Mount SOIC 8 5 x 4 x 1.5mm 1.5mm 5mm 6 V
New
RS Stock No. 190-6081
Mfr. Part No.DS2502P-E48+T&R
£1.268
Each (On a Reel of 4000)
Units
1024bit - 1-Wire - - OTP - Surface Mount TSOC 6 4 x 3.89 x 1.34mm 1.34mm 4mm 6 V
New
RS Stock No. 192-1488
Mfr. Part No.DS1982-F3+
£2.49
Each (In a Pack of 2)
Units
- - - - - - - - F3 MicroCan 2 17.36 (Dia.) x 3.1mm 3.1mm - -
New
RS Stock No. 192-1512
Mfr. Part No.DS2502S+
£1.964
Each (In a Pack of 5)
Units
1kbit 1K x 1 bit 1-Wire 120µs 11.5V OTP In System Surface Mount SOIC 8 5 x 4 x 1.5mm 1.5mm 5mm 6 V
New
RS Stock No. 190-6965
Mfr. Part No.DS2502P-E48+T&R
£2.04
Each (In a Pack of 5)
Units
- - - - - - - - - - - - - -
New
RS Stock No. 190-6082
Mfr. Part No.DS2502R+T&R
£0.904
Each (On a Reel of 3000)
Units
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