SN74AHCT594QPWRQ1

Shift Registers Overview

The SN74AHCT594-Q1 is an automotive-grade, 8-bit serial-in, parallel-out shift register with an output storage register. It operates within a supply voltage range of 4.5V to 5.5V and supports temperatures from -40°C to +125°C. The device features TTL-compatible inputs and balanced CMOS push-pull outputs capable of sourcing and sinking up to 8mA. Maximum propagation delay is 12.4ns at 5V with a 50pF load. It includes separate clocks for the shift and storage registers, along with active-low asynchronous clear inputs for both sections.

Shift Registers Feature Summary

• AEC-Q100 qualified for automotive applications with specified temperature grades and ESD classifications
• TTL-compatible CMOS inputs designed for direct interfacing with standard logic devices
• Balanced CMOS push-pull outputs providing symmetric current drive capabilities
• Wettable flank package option available to facilitate automatic optical inspection

Shift Registers Applications

• Increasing the number of outputs on a microcontroller
• Temporarily storing up to 8 bits of data
• Cascading multiple units to control seven-segment displays

Shift Registers Procurement Notes

Verify that the specific ordering suffix matches the required package type, as the device is available in TSSOP-16 and wettable flank QFN configurations. Confirm AEC-Q100 qualification status is required for the target automotive application. Ensure input signals transition rapidly to prevent oscillation due to the TTL-compatible nature of the CMOS inputs. Check thermal resistance values against the selected package variant during layout design.

Shift Registers Selection Notes

Select this component when an 8-bit shift register with independent storage clocking is needed for automotive systems. The AHCT series ensures compatibility with TTL logic levels while maintaining CMOS performance characteristics. Consider the wettable flank package if automated optical inspection reliability is a priority. Verify that the maximum capacitive load does not exceed 50pF to maintain specified timing parameters.

Shift Registers Part Context

This part belongs to the SN74AHCT594-Q1 family of automotive shift registers. It is distinct from non-automotive variants by its extended temperature range and qualification standards. The device integrates both shift and storage functions into a single 16-pin package, offering a compact solution for serial-to-parallel conversion tasks in vehicle electronics.

Shift Registers Replacement Considerations

SN74AHCT594PWQ1

Shift Registers FAQ

How are unused inputs handled?

Unused TTL-compatible CMOS inputs must never be left floating. They should be terminated to VCC or GND using a pull-up or pull-down resistor, typically 10kΩ, to prevent oscillation and excessive power consumption.

What is the function of the QH' output?

The QH' output provides a direct connection to the last stage of the internal shift register. It allows for cascading multiple devices by connecting this pin to the serial input (SER) of the next unit.