SN74LV8T595PWR

Shift Registers Overview

The SN74LV8T595PWR is an 8-bit shift register with tri-state outputs and integrated logic-level shifting, housed in a 16-pin TSSOP package. It operates within a supply voltage range of 1.65V to 5.5V, supporting 5.5V tolerant inputs for down-translation and reduced threshold inputs for up-translation. The device features separate clocks for the shift and storage registers, a direct overriding clear input, and serial cascading capability. It provides balanced CMOS push-pull outputs and includes a Power-On Reset circuit for known start-up states.

Shift Registers Feature Summary

• Integrated logic-level shifter supports bidirectional voltage translation between low-voltage domains (1.2V–3.3V) and 5V systems.
• Latching logic architecture ensures consistent power-up behavior through a dedicated Power-On Reset circuit.
• Balanced CMOS push-pull outputs provide symmetric sourcing and sinking capabilities with high drive strength.
• Input pins are tolerant of 5.5V signals, enabling safe interfacing with higher voltage logic levels.

Shift Registers Applications

• Digital signage systems
• Microcontroller output expansion
• Indicator LED control

Shift Registers Procurement Notes

Verify the specific ordering suffix 'PWR' corresponds to the Polyimide Tape-and-Reel packaging variant of the PW (TSSOP) package. Confirm that the component matches the SCAS994 datasheet revision. Ensure the procurement channel sources production data directly from Texas Instruments or authorized distributors to guarantee authenticity and traceability.

Shift Registers Selection Notes

Select this component when system design requires expanding microcontroller I/O lines while simultaneously managing voltage level mismatches between different logic families. The integrated level-shifting capability eliminates the need for external translators. Consider the thermal performance of the TSSOP package if operating near maximum current limits or elevated temperatures.

Shift Registers Part Context

This part belongs to the SN74LV8T595 family, which integrates shift register functionality with LVxT enhanced input voltage characteristics. The 'PWR' designation specifically identifies the tape-and-reel version of the 16-pin Thin-Shrink Small-Outline Package (TSSOP). This configuration is optimized for automated surface-mount assembly processes.

Shift Registers Replacement Considerations

Direct functional substitutes include other SN74LV8T595 variants such as the SN74LV8T595PW (tube packaging) or SN74LV8T595BQB (WQFN packaging), provided the physical footprint and pinout compatibility are verified for the specific PCB layout constraints.

Shift Registers FAQ

How does the device handle unknown states during power-up?

The SN74LV8T595 includes a Power-On Reset (POR) circuit that sets all latching circuits to a known state during the supply voltage ramp, ensuring consistent start-up behavior.

Can unused inputs be left floating?

No, unused inputs must not be left floating. They should be terminated at a valid high or low voltage level, typically using a pull-up or pull-down resistor, to prevent excessive power consumption and oscillations.