UPD43257B Datasheet, PDF (1/20 Pages) NEC – 256K-BIT CMOS STATIC RAM 32K-WORD BY 8-BIT

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 Operating supply Operating ambient
ns (MAX.)
voltage
temperature
At operating
V
°C
mA (MAX.)
µPD43257B-xxL
70, 85
4.5 to 5.5
0 to 70
45
µPD43257B-xxLL
45
Note TA ≤ 40 °C, VCC = 3.0 V
Supply current
At standby
µA (MAX.)
At data retention
µA (MAX.) ^Note
50
3
15
2
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.
D43257B
JAPAN
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)
The mark 5 shows major revised points.
Date Published June 2000 NS CP (K)
©
Printed in Japan
1992