The LS603A memory refresh controllers contain one 8-bit synchronous counter, nine 3-state buffer drivers, four RC controlled multivibrators, and other control circuitry on a single monolithic chip. These devices are designed to provide RAS-only refresh on 4K, 16K, and 64K dynamic RAMs. The LS600A and LS601A provide transparent refresh while the LS603A provides cycle steal refresh. in addition, a burst-mode timer is provided to warn the CPU that the maximum allowable refresh time is about to be violated.

Features :-

• Controls Refresh Cycle of 4K, 16K, and 64K Dynamic RAMS
• Creates Static RAM Appearance
• Choice of Transparent. Cycle Steal, or Burst Refresh Modes
• 3-State Outputs Drive Bus Lines Directly
• Critical Times Are User RC-Programmable to Optimize System Performance

Specifications :-

• Supply Voltage Min : 4.75V
• Supply Voltage Max : 5.25V
• High Level output Current Max : -2.6mA
• Low Level output Current Max : 24mA
• Supply Current : 85mA

Package Includes :-

1 X 74LS603 Memory Refresh Controllers IC (74603) DIP-20 Package