M27W400 Datasheet | STMicroelectronics

DESCRIPTION The M27W400 is a low voltage 4 Mbit EPROM offered in the two range UV (Ultra Violet Erase) and OTP (one time programmable). It is ideally suited for microprocessor systems requiring large data or program storage. It is organised as either 512 Kwords of 8 bit or 256 Kwords of 16 bit. The pinout is patible with the most mon 4 Mbit Mask ROM. The M27W400 operates in the read mode with a supply voltage as low as 2.7V at - 40 to 85°C temperature range. The decrease in operating power allows either a reduction of the size of the battery or an increase in the time between battery recharges. The FDIP40W (window ceramic frit-seal 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 application where the content is programmed only one time and erasure is not required, the M27W400 is offered in PDIP40 and PLCC44 packages. 18 A0-A17 15 Q15A- 1 Q0-Q14 E G BYTEVPP M27W400 AI03096 January 2000 1/15 Figure 2A. DIP Connections Figure 2B. LCC Connections A17 A7 A6 A5 A4 A3 A2 A1 A0 E VSS G Q0 Q8 Q1 Q9 Q2 Q10 Q3 Q11 1 40 2 39 3 38 4 37 5 36 6 35 7 34 33 8 32 9 31 10 M27W400 30 11 29 12 28 13 27 14 26 15 25 16 17 24 18 23 19 22 20 21 AI03097 A8 A9 A10 A11 A12 A13 A14 A15 A16 BYTEVPP VSS Q15A- 1 Q7 Q14 Q6 Q13 Q5 Q12 Q4 VCC A4 A3 A2 A1 A0 E VSS G Q0 Q8 Q1 A5 A6 A7 A17 NC NC NC A8 A9 A10 A11 1 44 A12 A13 A14 A15 A16 BYTEVPP VSS Q15A- 1 Q7 Q14 Q6 12 M27W400 34 23 Q9 Q2 Q10 Q3 Q11 NC VCC Q4 Q12 Q5 Q13 AI03604 Table 1. Signal Names A0-A17 Q0-Q7 Q8-Q14 Q15A- 1 E G BYTEVPP VCC VSS Address Inputs Data Outputs Data Outputs Data Output / Address Input Chip Enable Output Enable Byte Mode / Program Supply Supply Voltage Ground DEVICE OPERATION The operating modes of the M27W400 are listed in the Operating Modes Table. A single power supply is required in the read mode. All inputs are TTL patible except for...