The TMS27C240 is a 262144-bit 16-bit (4194304-bit) ultraviolet-light erasable, electrically programmable read-only memory (EPROM). The TMS27PC240 is a 262144-bit 16-bit (4194304-bit) one-time programmable (OTP) electrically programmable read-only memory (PROM). These devices are fabricated using power-saving CMOS technology for high speed and simple interface with MOS and bipolar circuits. All inputs (including program data inputs) can be driven by 74 series TTL circuits without the use of external pull-up resistors. Each output can drive one 74 series TTL circuit.
This document is a datasheet for the TMS27C240 and TMS27PC240 series of read-only memories (ROMs). The TMS27C240 is an ultraviolet-light erasable EPROM, while the TMS27PC240 is a one-time programmable (OTP) PROM. Both devices feature a 262,144 x 16-bit capacity and are fabricated using power-saving CMOS technology for high-speed operation and simple interfacing with TTL or MOS circuits.
| Capacity | 262144 by 16-bit (4194304-bit) |
|---|---|
| Technology | Power-Saving CMOS |
| Supply Voltage (Read) | 5 V |
| Programming Voltage (Vpp) | 13 V |
| Latchup Immunity | 250 mA |
| Operating Temperature (JE) | -40°C to 85°C |
No, logic lows programmed into the TMS27PC240 OTP PROM cannot be erased.
The device is erased by exposing it to a high-intensity ultraviolet light with a wavelength of 2537 A.
A 12-mW/cm², filterless UV lamp erases the device in 21 minutes.