SN74LV8T595BQBR

Shift Registers Overview

The SN74LV8T595BQBR is an 8-bit shift register with tri-state outputs and logic-level shifting capabilities. It operates within a supply voltage range of 1.65V to 5.5V, featuring 5.5V tolerant input pins for down-translation support. The device includes a serial-in, parallel-out shift register feeding an 8-bit D-type storage register with separate clocks. It supports up-translation from lower voltages (1.2V–3.3V) and down-translation to 1.8V–3.3V. The BQB package is a 16-pin WQFN measuring 3.5mm x 2.5mm. Latching logic ensures a known power-up state via an internal Power On Reset circuit.

Shift Registers Feature Summary

• Integrated logic-level shifter supporting bidirectional voltage translation between low-voltage domains and 5V tolerant interfaces.
• Latching logic architecture with a dedicated Power On Reset circuit ensuring consistent and known start-up behavior.
• Balanced CMOS push-pull outputs providing symmetric sourcing and sinking current capabilities with high impedance states.

Shift Registers Applications

• Digital signage systems
• Controlling indicator LEDs
• Expanding microcontroller output counts

Shift Registers Procurement Notes

Verify the specific ordering suffix 'BQBR' corresponds to the WQFN package variant during procurement. Confirm that the component matches the official Texas Instruments datasheet specifications for the SN74LV8T595 family. Ensure compatibility with the required operating temperature range and supply voltage conditions specified in the recommended operating conditions table before integration.

Shift Registers Selection Notes

Select this component when interfacing between different voltage domains requiring both data storage and level translation. The integrated level shifter eliminates external components for voltage conversion. Consider the thermal performance of the WQFN package if high ambient temperatures are expected. Verify that the input signal transition rates meet the specified limits to prevent excessive power consumption or oscillation.

Shift Registers Part Context

This part belongs to the SN74LV8T595 family of 8-bit shift registers with logic-level shifting. The 'BQBR' suffix indicates the specific WQFN package configuration. This family is designed for applications requiring reliable data latching and voltage translation across multiple supply rails, combining standard shift register functionality with enhanced input/output voltage tolerance features.

Shift Registers Replacement Considerations

Direct substitutes include other SN74LV8T595 variants with different packaging options such as PW (TSSOP). Ensure any replacement maintains the same logic function, voltage tolerance levels, and pinout compatibility. Verify that the alternative package meets the thermal and mechanical requirements of the target application.

Shift Registers FAQ

How does the device handle unknown states after power is applied?

The device includes a Power On Reset (POR) circuit that sets the states of all latching circuits during the power-up ramp, ensuring a known start-up behavior rather than an undefined state.

What is the purpose of the QH' pin?

QH' serves as the serial output of the shift register, allowing multiple devices to be cascaded for expanding the number of available bits without additional control lines.