This document describes the features and characteristics of ISSI's IS41C16257A and IS41LV16257A high-performance CMOS dynamic random access memories, including fast access and cycle time, TTL compatible inputs and outputs, refresh interval and mode, JEDEC standard pinout, and single power supply.
The ISSI IS41C16257A and IS41LV16257A are 262,144 x 16-bit high-performance CMOS Dynamic Random Access Memories. These devices support Fast Page Mode allowing up to 512 random accesses within a single row with access cycle times as short as 12 ns per 16-bit word.
| Memory Capacity | 262,144 x 16-bit (4-MBIT) |
|---|---|
| Refresh Interval | 512 cycles/8 ms |
| Max. RAS Access Time (tRAC) | 60 ns (-35°C), 110 ns (-60°C) |
| Min. Fast Page Mode Cycle Time (tPC) | 25 ns (-35°C), 42.5 ns (-60°C) |
| Supply Voltage | 5V ± 10% or 3.3V ± 10% |
| Operating Temperature | 0 to +70 °C |
To retain data, 512 refresh cycles are required in each 8 ms period.
An initial pause of 200 µs is required followed by a minimum of eight initialization cycles before proper device operation.