M87C257

M87C257 ADDRESS LATCHED 256K (32K x 8) UV EPROM and OTP EPROM INTEGRATED ADDRESS LATCH FAST ACCESS TIME: 45ns LOW POWER “CMOS” CONSUMPTION: – Active Current 30mA – Standby Current 100µA PROGRAMMING VOLTAGE: 12.75V ELECTRONIC SIGNATURE for AUTOMATED PROGRAMMING PROGRAMMING TIMES of AROUND 3sec. (PRESTO II ALGORITHM) 28 1 FDIP28W (F) PLCC32 (C) Figure 1. Logic Diagram DESCRIPTION The M87C257 is a high speed 262,144 bit UV erasable and electrically programmable EPROM. The M87C257 incorporates latches for all address inputs to minimize chip count, reduce cost, and simplify the design of multiplexed bus systems. The Window Ceramic Frit-Seal Dual-in-Line package has a transparent lid which allows the user to expose the chip to ultraviolet light to erase the bit pattern. A new pattern can then be written to the device by following the programming procedure. For applications where the content is programmed only one time and erasure is not required, the M87C257 is offered in Plastic Leaded Chip Carrier, package. VCC 15 A0-A14 8 Q0-Q7 E G M87C257 Table 1. Signal Names A0 - A14 Q0 - Q7 E G ASVPP VCC VSS Address Inputs Data Outputs Chip Enable Output Enable Address Strobe / Program Supply Supply Voltage Ground ASVPP VSS AI00928B June 1996 1/13 M87C257 Figure 2A. DIP Pin Connections Figure 2B. LCC Pin Connections Q1 Q2 AI00929 VSS DU Q3 Q4 Q5 AI00930 ASVPP A12 A7 A6 A5 A4 A3 A2 A1 A0 Q0 Q1 Q2 VSS 28 1 27 2 26 3 25 4 24 5 23 6 22 7 M87C257 21 8 20 9 19 10 18 11 17 12...