EPROM Information
Image Credit: Allied Electronics, Inc. | Digi-Key Corporation
Erasable programmable read-only memory (EPROM) chips are programmable, reusable computer chips that can be erased using ultraviolet light and reprogrammed with a PROM programmer or PROM burner. Programming or burning an EPROM chip injects electrons with an elevated voltage into the floating gate a field-effect transistor, trapping the electrons and forcing a reading of zero. Erasing an EPROM chip bombards the chip with ultraviolet radiation through a quartz window to provide the trapped electrons with enough energy to escape the floating gate. To prevent slow erasure over a period of years from sunlight and fluorescent lights, the quartz window is covered with an opaque label during normal use.
EPROM Applications
EPROM is used widely in personal computers because it enables manufacturers to change the contents of programmable read-only memory before the computer is shipped. Since EPROM chips do not require power to retain their data, they are commonly used to store BIOS information and basic software for modems, video cards, and other peripherals. Flash EPROM or FEPROM incorporates FLASH technology and is available from some chip manufacturers. Other architectural considerations include density, which is the capacity of the memory chip expressed in bits, as well as the number of rows and columns. With EPROM, each row stores a memory word and connects to a word line for addressing purposes. The number of columns equals the bits per word. Each column connects to a sense / write circuit.
Selection Criteria
Selecting EPROM chips requires the selection of a serial or parallel data bus and the analysis of several performance specifications.
- Operating current is the minimum current needed for active chip operation.
- Standby current is the minimum current needed during inactivity.
- Power dissipation, which is generally expressed in watts or milliwatts, is the total power consumption of the device.
- Measured in nanoseconds (ns), access time indicates the speed of memory and represents a cycle that begins when the CPU sends a request to memory and ends when the CPU receives the data requested.
- Some EPROM chips support a specific temperature range and feature mechanical and electrical specifications that are suitable for commercial or industrial applications.
- Other EPROM chips meet screening levels for military specifications (MIL-SPEC).
EPROM chips vary in terms of supply voltage, logic family, and package type.
- Common logic families include standard, fast, high-speed and advanced CMOS; emitter coupled logic (ECL); TTL and Fairchild advanced Schottky TTL (FAST); gunning technology; and crossbar switch technology (CBT).
- Common package types include ball grid array (BGA), quad flat package (QFP), single in-line package (SIP), and dual in-line package (DIP). Many packaging variants are available for EPROM chips.
- Common packaging materials include plastic, ceramic, metal, and glass.
Standards
- EPROM datasheet 2764
- datasheet 2732 EPROM
- EPROM copier
- EPROM datasheet 2716
- memoria EPROM 2716
- 2708 EPROM
- 2716 EPROM emulator
- 2732a EPROM
- 27c010 EPROM
- 27c020 EPROM
- 27c128 EPROM
- EPROM 27010
- EPROM 27128
- EPROM 2764 pinout
- intel EPROM datasheet
- USB programmer EPROM
- windows screen crossbar
- 2732 data sheet EPROM
- 28 pin EPROM
- data sheet 2716 EPROM
- programmable otp EPROM
- universal programmer EPROM