DATA SHEET
MOS INTEGRATED CIRCUIT
µPD43257B
256K-BIT CMOS STATIC RAM
32K-WORD BY 8-BIT
Description
The µPD43257B is a high speed, low power, and 262,144 bits (32,768 words by 8 bits) CMOS static RAM.
Battery backup is available. And the µPD43257B has two chip enable pins (/CE1, CE2) to extend the capacity.
The µPD43257B is packed in 28-pin plastic DIP and 28-pin plastic SOP.
Features
• 32,768 words by 8 bits organization
• Fast access time: 70, 85 ns (MAX.)
• Low VCC data retention: 2.0 V (MIN.)
• Two Chip Enable inputs: /CE1, CE2
Part number
Access time
ns (MAX.)
Operating supply Operating ambient
Supply current
70, 85
temperature
At operating
At standby
At data retention
V
µPD43257B-xxL
voltage
°C
mA (MAX.)
µA (MAX.)
µA (MAX.) Note
4.5 to 5.5
0 to 70
45
50
3
45
15
2
µPD43257B-xxLL
Note TA ≤ 40 °C, VCC = 3.0 V
Version X
This Data sheet can be applied to the version X. This version is identified with its lot number. Letter X in the fifth
character position in a lot number signifies version X.
JAPAN
D43257B
X
Lot number
The information in this document is subject to change without notice. Before using this document, please
confirm that this is the latest version.
Not all devices/types available in every country. Please check with local NEC representative for
availability and additional information.
Document No. M10693EJ7V0DS00 (7th edition)
Date Published June 2000 NS CP (K)
Printed in Japan
The mark 5 shows major revised points.
©
1992
