Overview
The M27C256B-90F6 is a 256 Kbit EPROM (Erasable Programmable Read-Only Memory) produced by STMicroelectronics. This device is available in both UV (ultra violet erase) and OTP (one time programmable) versions, making it versatile for various microprocessor system applications. The M27C256B is organized as 32,768 by 8 bits and features a single power supply operation in read mode, with low power consumption and fast access times.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Memory Size | 256 Kbit (32Kb x 8) | |
| Supply Voltage | 5V ± 10% | V |
| Access Time | 90 ns | ns |
| Active Current | 30 mA at 5 MHz | mA |
| Standby Current | 100 µA | µA |
| Programming Voltage | 12.75V ± 0.25V | V |
| Programming Time | 100 µs/word | µs/word |
| Operating Temperature Range | –40 to 125 °C | °C |
| Storage Temperature Range | –65 to 150 °C | °C |
Key Features
- Low power consumption with active current of 30 mA at 5 MHz and standby current of 100 µA.
- Fast access time of 90 ns.
- Single power supply operation in read mode.
- Electronic Signature mode for device identification.
- Available in various packages including FDIP28W, PDIP28, PLCC32, and TSOP28.
- UV erase capability for the UV EPROM version.
Applications
The M27C256B is ideally suited for microprocessor systems, embedded systems, and other applications where non-volatile memory is required. It is particularly useful in environments where data needs to be stored permanently but can be updated occasionally, such as in firmware storage, configuration data, and other similar use cases.
Q & A
- What is the memory size of the M27C256B?
The M27C256B has a memory size of 256 Kbit, organized as 32,768 by 8 bits. - What are the different package options available for the M27C256B?
The M27C256B is available in FDIP28W, PDIP28, PLCC32, and TSOP28 packages. - What is the access time of the M27C256B-90F6?
The access time of the M27C256B-90F6 is 90 ns. - How is the M27C256B programmed?
The M27C256B is programmed by applying a programming voltage of 12.75V ± 0.25V to the VPP input, with the chip enable (E) pulsed to VIL. Data is applied in parallel to the data output pins. - What is the Electronic Signature mode used for?
The Electronic Signature mode allows the reading out of a binary code to identify the manufacturer and type of the EPROM, useful for programming equipment to match the device with its corresponding programming algorithm. - What are the operating temperature ranges for the M27C256B?
The operating temperature range is –40 to 125 °C, and the storage temperature range is –65 to 150 °C. - How does the standby mode reduce power consumption?
In standby mode, the supply current is reduced to 100 µA by applying a CMOS high signal to the E input. - Can the M27C256B be erased and reprogrammed?
Yes, the UV EPROM version of the M27C256B can be erased using ultraviolet light and then reprogrammed. - What is the programming time per word for the M27C256B?
The programming time per word is 100 µs. - What are the input and output voltage levels for the M27C256B?
The input and output voltage levels are TTL compatible, with input low voltage (VIL) ranging from –0.3 to 0.8 V and input high voltage (VIH) ranging from 2 V to VCC + 1 V.
