4 MBIT (512KB X8) UV EPROM AND OTP ROM The **M27C4001** is a **4 Mbit (512Kb x8) UV EPROM** manufactured by **STMicroelectronics**.
### **Key Specifications:**
- **Memory Size:** 4 Mbit (512K x 8 bits)
- **Supply Voltage (VCC):** 5V ±10%
- **Access Time:** 55 ns, 70 ns, 90 ns (depending on speed grade)
- **Operating Temperature Range:** 0°C to +70°C (commercial), -40°C to +85°C (industrial)
- **Programming Voltage (VPP):** 12.5V
- **Standby Current:** 100 µA (max)
- **Active Current:** 30 mA (max)
- **Package Options:**
- **CERDIP (Windowed):** 32-pin
- **PLCC (Windowed):** 32-pin
- **LCC (Windowed):** 32-pin
### **Features:**
- **UV Erasable:** Can be erased by exposure to UV light (typically 15-20 minutes under a UV lamp).
- **CMOS Technology:** Low power consumption compared to NMOS EPROMs.
- **TTL-Compatible Inputs/Outputs:** Ensures compatibility with standard logic levels.
- **Programmable via Standard EPROM Programmers:** Supports fast programming algorithms.
- **Data Retention:** 10 years minimum.
- **On-Chip Address and Data Latches:** Simplifies interfacing with microprocessors.
- **Single 5V Power Supply for Read Operations:** No additional voltage required during normal operation.
### **Applications:**
- Firmware storage in embedded systems
- Legacy computer BIOS
- Industrial control systems
- Automotive electronics (where UV erasability is required)
The M27C4001 is an older EPROM technology, now largely replaced by Flash memory, but remains useful in applications requiring UV erasability.
