Overview
The M27C256B-90B1 is a 256 Kbit EPROM (Erasable Programmable Read-Only Memory) produced by STMicroelectronics. This device is available in two ranges: UV (ultra violet erase) and OTP (one time programmable). It is organized as 32,768 by 8 bits, making it ideally suited for microprocessor systems. The M27C256B is offered in various packages, including FDIP28W (window ceramic frit-seal package), PDIP28, and PLCC32, with the FDIP28W package featuring a transparent lid for UV erasure. For environmentally friendly options, the device is also available in ECOPACK® packages, which are lead-free and comply with JEDEC Standard JESD97.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Supply Voltage in Read Operation | 5V ± 10% | V |
| Access Time | 90ns (for -90B1 speed grade) | ns |
| Active Current at 5MHz | 30mA | mA |
| Standby Current | 100µA | µA |
| Programming Voltage | 12.75V ± 0.25V | V |
| Programming Time per Word | 100µs | µs |
| Ambient Operating Temperature | –40 to 125°C | °C |
| Manufacturer Code | 20h | - |
| Device Code | 8Dh | - |
Key Features
- Single power supply required in read mode.
- Two control functions: Chip Enable (E) and Output Enable (G) for data access and output control.
- Standby mode reduces supply current to 100µA.
- Two-line output control for efficient use in larger memory arrays.
- Electronic signature mode for device identification.
- Available in ECOPACK® packages, which are lead-free and environmentally friendly.
Applications
The M27C256B-90B1 is suitable for a variety of applications, including microprocessor systems, embedded systems, and other memory-intensive applications where non-volatile memory is required. It is particularly useful in scenarios where data needs to be stored permanently but can be updated occasionally, such as in firmware storage, configuration data, and other forms of persistent storage.
Q & A
- What is the storage capacity of the M27C256B-90B1? The M27C256B-90B1 has a storage capacity of 256 Kbits, organized as 32,768 by 8 bits.
- What are the different package options available for the M27C256B? The M27C256B is available in FDIP28W, PDIP28, and PLCC32 packages.
- How is the M27C256B erased? The UV version of the M27C256B can be erased using ultra violet light, while the OTP version is one-time programmable and cannot be erased.
- What is the access time for the M27C256B-90B1? The access time for the M27C256B-90B1 is 90ns.
- What is the standby current of the M27C256B? The standby current of the M27C256B is 100µA.
- How is the device identified electronically? The device can be identified electronically through its manufacturer code (20h) and device code (8Dh) in electronic signature mode.
- What are the environmental benefits of the ECOPACK® packages? ECOPACK® packages are lead-free and comply with JEDEC Standard JESD97, making them environmentally friendly.
- What is the programming voltage for the M27C256B? The programming voltage for the M27C256B is 12.75V ± 0.25V.
- How long does it take to program one word in the M27C256B? It takes 100µs to program one word in the M27C256B.
- What are the operating temperature ranges for the M27C256B? The ambient operating temperature range for the M27C256B is –40 to 125°C.
