74LS189 PDF Datasheet – 64-BIT, Random Access Memory

This IC is a specific integrated circuit (IC) that belongs to the 74LS series of TTL (Transistor-Transistor Logic) logic chips. It is a 16×4-bit random access memory (RAM) chip, often used in digital systems for temporary data storage and retrieval.

Part Number: 74LS189


Package: 16 Pin DIP, SMD type

Manufacturer: Fairchild Semiconductor

Image and Pinouts:

74LS189 datasheet ttl


The 74LS189 is a high speed 64-bit RAM organized as a 16-word by 4-bit array. Address inputs are buffered to minimize loading and are fully decoded on-chip. The outputs are 3-state and are in the high impedance state whenever the chip select (CS) input is HIGH. The ouputs are active only in the read mode and the output is the complement of the stored data.

Block Diagram:

74LS189 datasheet ttl


1. 3-State ouputs for data bus applicatons

2. Buffered inputs minimize loading

3. Address decoding on-chip

4. Diode clamped inputs minimize ringing

74LS189 PDF Datasheet