SN74ALS990N

Overview

The SN74ALS990N is an 8-bit D-type transparent read-back latch manufactured by Texas Instruments. It operates within a supply voltage range of 4.5 V to 5.5 V and supports propagation delays of 24 ns. The device features non-inverting polarity with low-level output current of 32 mA and high-level output current of -2.6 mA. It is housed in a 20-pin DIP package and functions within an operating temperature range of 0°C to +70°C.

Feature Summary

• Provides 8-bit data storage with transparent latch functionality
• Includes read-back capability for internal state verification
• Supports standard TTL-compatible logic levels

Applications

• Parallel data buffering in digital systems
• Temporary storage in microprocessor interfaces
• State retention in control logic circuits

Procurement Notes

Verify the specific suffix 'N' indicates the 20-pin PDIP package variant. Confirm the manufacturer is Texas Instruments, as other vendors may produce compatible parts with different specifications. Check RoHS compliance status directly from the official datasheet or manufacturer documentation before procurement.

Selection Notes

Select this component when an 8-bit latch with read-back functionality is required. Ensure the design accommodates the 20-pin DIP footprint and the specified voltage and current limits. Consider the 24 ns propagation delay for timing constraints in the target application circuit.

Part Context

This part belongs to the SN74ALS series of advanced low-power Schottky logic devices. It serves as a memory element within the broader family of Texas Instruments logic ICs, providing reliable data latching for digital applications requiring parallel input and output handling.

Replacement Considerations

Check for direct cross-references such as SN74ALS990DR or equivalent 8-bit latches from other manufacturers. Verify pin compatibility and electrical parameters before substitution.