74LS256PC

Latches Overview

The SN74LS256PC is a dual 4-bit addressable latch manufactured by National Semiconductor. It operates on a 5 V supply with a maximum current of 25 mA and features a propagation delay of 30 ns. The device utilizes LS-TTL logic technology and is housed in a 16-pin plastic DIP package (DIP16,.3). It contains two functional units, each handling 4 bits, with a maximum output current of 8 mA. The component is designed for operation within a temperature range of -55 °C to 70 °C.

Latches Feature Summary

• Dual independent 4-bit latching functionality
• Addressable data storage capability
• LS-TTL logic compatibility

Latches Applications

• Digital system data buffering
• Microprocessor interface circuits
• Memory address latching

Latches Procurement Notes

Verify the manufacturer designation, as National Semiconductor assets were acquired by Texas Instruments. Confirm the specific suffix 'PC' corresponds to the PDIP-16 package variant. Check RoHS compliance status, as original versions may be non-compliant. Ensure the datasheet matches the intended TTL voltage levels and speed requirements for the target application.

Latches Selection Notes

Select this component when dual 4-bit addressable latching is required in a standard DIP package. Verify that the LS-TTL input/output characteristics match the driving and loading circuits. Consider the 30 ns propagation delay against system timing constraints. Ensure the 5 V supply voltage is stable within specified limits for reliable operation.

Latches Part Context

The 74LS256 series belongs to the standard 74xx logic family, specifically the Low-power Schottky (LS) subset. This family provides a balance between power consumption and switching speed. The 74LS256 variant specifically offers addressable latching, distinguishing it from simple D-type latches like the 74LS75 or 74LS273.

Latches Replacement Considerations

Compatible substitutes include the SN74LS256N and SN74LS256PC from other manufacturers such as NXP or Motorola. Verify pinout compatibility and electrical specifications before substitution.