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W27E257
32K × 8 ELECTRICALLY ERASABLE EPROM
GENERAL DESCRIPTION
The W27E257 is a high-speed, low-power Electrically Erasable and Programmable Read Only Memory organized as 32768 × 8 bits that operates on a single 5 volt power supply. The W27E257 provides an electrical chip erase function. This part was the same EPROM Writer's utilities as the W27E256.
FEATURES
• High speed access time: 100/120/150 nS (max.)
• Read operating current: 15 mA (typ.) • Erase/Programming operating current
1 mA (typ.) • Standby current: 5 µA (typ.) • Single 5V power supply
• +14V erase/+12V programming voltage • Fully static operation • All inputs and outputs directly TTL/CMOS
compatible
• Three-state outputs • Available packages: 28-pin 600 mil DIP and
32-pin PLCC
PIN CONFIGURATIONS
BLOCK DIAGRAM
VPP A12
A7 A6 A5 A4 A3 A2 A1 A0 Q0 Q1 Q2 GND
1 2 3 4 5 6 28-pin 7 DIP 8 9 10 11 12 13 14
28 27 26 25 24 23 22 21 20 19 18 17 16 15
VCC A14 A13 A8 A9 A11
OE A10
CE Q7 Q6 Q5 Q4 Q3
AV .