GENERAL DESCRIPTION
The SMJ27C512 is a set of 65536 by 8-bit (524,288-bit), ultraviolet (UV) light erasable, electrically programmable read-only memories. 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 Series 54 TTL circuits without the use of external pullup resistors. Each output can drive one Series 54 TTL circuit without external resistors. The data outputs are 3-state for connecting multiple devices to a common bus. The SMJ27C512 is pin-compatible with existing 28-pin 512K ROMs and EPROMs.
Because this EPROM operates from a single 5V supply (in the read mode), it is ideal for use in microprocessor-based systems. One other supply (13V) is needed for programming. All programming signals are TTL level. This device is programmable by the SNAP! Pulse programming algorithm. The SNAP! Pulse programming algorithm uses a VPP of 13V and a VCC of 6.5V for a nominal programming time of seven seconds. For programming outside the system, existing EPROM programmers can be used. Locations may be programmed singly, in blocks, or at random.

FEATURES
• Organized 65,536 x 8
• High-reliability MIL-PRF-38535 processing
• Single +5V ±10% power supply
• Pin-compatible with existing 512K read-only memories (ROMs) and electrically programmable ROMs (EPROMs)
• All inputs/outputs fully TTL compatible
• Power-saving CMOS technology
• Very high-speed SNAP! Pulse Programming
• 3-state output buffers
• 400mV minimum DC noise immunity with standard TTL loads
• Latchup immunity of 250mA on all input and output lines
• Low power dissipation (CMOS input levels)
   Active - 193mW (MAX)
   Standby - 1.7mW (MAX)