Overview
The M27C256B-12B1 is a 256 Kbit EPROM (Erasable Programmable Read-Only Memory) produced by STMicroelectronics. This device is available in two main types: UV (ultra violet erase) and OTP (one time programmable). It is organized as 32,768 by 8 bits, making it suitable for microprocessor systems. The UV version comes in a window ceramic frit-seal package (FDIP28W) that allows for erasure using ultraviolet light, while the OTP versions are available in PDIP28 and PLCC32 packages. The M27C256B is also offered in ECOPACK® packages, which are lead-free and comply with environmental standards.
Key Specifications
| Parameter | Description | Value |
|---|---|---|
| Memory Size | 256 Kbit (32Kb × 8) | - |
| Supply Voltage (Read) | 5V ± 10% | - |
| Access Time | 45ns (minimum) | - |
| Active Current | 30mA at 5MHz | - |
| Standby Current | 100µA | - |
| Programming Voltage | 12.75V ± 0.25V | - |
| Programming Time | 100µs/Word | - |
| Electronic Signature | Manufacturer Code: 20h, Device Code: 8Dh | - |
| Packages | FDIP28W, PDIP28, PLCC32 | - |
Key Features
- Low Power Consumption: Active current of 30mA at 5MHz and standby current of 100µA.
- Two-Line Output Control: Allows for efficient use in larger memory arrays, minimizing power dissipation and preventing output bus contention.
- Programming Algorithm: Supports PRESTO II programming algorithm for efficient programming with guaranteed margins.
- Environmental Compliance: Available in ECOPACK® packages, which are lead-free and comply with JEDEC Standard JESD97.
- Electronic Signature: Provides manufacturer and device codes for identification.
Applications
The M27C256B-12B1 is ideally suited for microprocessor systems and other applications requiring non-volatile memory. It can be used in various fields such as:
- Embedded systems requiring programmable memory.
- Industrial control systems.
- Automotive electronics.
- Consumer electronics.
Q & A
- What is the memory size of the M27C256B-12B1?
The memory size is 256 Kbit, organized as 32,768 by 8 bits.
- What are the different package types available for the M27C256B?
The device is available in FDIP28W, PDIP28, and PLCC32 packages.
- What is the supply voltage for read operations?
The supply voltage is 5V ± 10%.
- What is the access time of the M27C256B-12B1?
The minimum access time is 45ns.
- How does the standby mode reduce power consumption?
In standby mode, the supply current is reduced to 100µA by applying a CMOS high signal to the E input.
- What is the programming voltage and time for the M27C256B?
The programming voltage is 12.75V ± 0.25V, and the programming time is 100µs per word.
- What is the PRESTO II programming algorithm?
The PRESTO II algorithm allows for efficient programming with guaranteed margins, typically taking 3.5 seconds to program the entire array.
- How does the two-line output control function work?
The two-line control function uses Chip Enable (E) and Output Enable (G) to manage memory selection and output, ensuring low power dissipation and preventing output bus contention.
- What are the electronic signature codes for the M27C256B?
The manufacturer code is 20h, and the device code is 8Dh.
- Are the M27C256B packages environmentally compliant?
Yes, the M27C256B is available in ECOPACK® packages, which are lead-free and comply with environmental standards).
