The AT27C256R is a low-power, high-performance 262,144-bit one-time programmable read-only memory (OTP EPROM) organized 32K by 8 bits. It requires only one 5V power supply in normal read mode operation. Any byte can be accessed in less than 45 ns, eliminating the need for speed-reducing WAIT states on high-performance microprocessor systems. Atmel’s scaled CMOS technology provides low-active power consumption and fast programming. Power consumption is typically only 8 mA in Active Mode and less than 10 µA in Standby.
27C256 Pinout
27C256 Pin Configuration
| Pin Number | Pin No | Description |
|---|---|---|
| 1 | VPP | Programming Supply |
| 2 | A12 | Address Input |
| 3 | A7 | Address Input |
| 4 | A6 | Address Input |
| 5 | A5 | Address Input |
| 6 | A4 | Address Input |
| 7 | A3 | Address Input |
| 8 | A2 | Address Input |
| 9 | A1 | Address Input |
| 10 | A0 | Address Input |
| 11 | O0 | Data Output |
| 12 | O1 | Data Output |
| 13 | O2 | Data Output |
| 14 | GND | Ground |
| 15 | O3 | Data Output |
| 16 | O4 | Data Output |
| 17 | O5 | Data Output |
| 18 | O6 | Data Output |
| 19 | O7 | Data Output |
| 20 | CE’ | Chip Enable |
| 21 | A10 | Address Input |
| 22 | OE’ | Output Enable/Program Supply |
| 23 | A11 | Address Input |
| 24 | A9 | Address Input |
| 25 | A8 | Address Input |
| 26 | A13 | Address Input |
| 27 | A14 | Address Input |
| 28 | VCC | Positive Power Supply |
27C256 Key Features
- High Reliability CMOS Technology
- 2,000V ESD Protection
- 200 mA Latchup Immunity
- Rapid Programming Algorithm – 100 µs/byte (typical)
- CMOS and TTL Compatible Inputs and Outputs
- Integrated Product Identification Code
- Commercial, Industrial and Automotive Temperature Ranges
- JEDEC Standard Packages
- 28-Lead 600-mil PDIP
- 32-Lead PLCC
- 28-Lead TSOP and SOIC
You can download this datasheet for 27C256 256K 150ns CMOS EPROM – Datasheet from the link given below:
