The 74HC595 consists of an 8−bit shift register and an 8−bit D−type latch with three−state parallel outputs. The shift register accepts serial data and provides a serial output. The shift register also provides parallel data to the 8−bit latch. The shift register and latch have independent clock inputs. This device also has an asynchronous reset for the shift register.
The HC595 directly interfaces with the SPI serial data port on CMOS MPUs and MCUs.

FEATUREs
• Output Drive Capability: 15 LSTTL Loads
• Outputs Directly Interface to CMOS, NMOS, and TTL
• Operating Voltage Range: 2.0 to 6.0 V
• Low Input Current: 1.0 A
• High Noise Immunity Characteristic of CMOS Devices
• In Compliance with the Requirements Defined by JEDEC Standard No. 7A
• ESD Performance: HBM  2000 V; Machine Model  200 V
• Chip Complexity: 328 FETs or 82 Equivalent Gates
• Improvements over HC595
    − Improved Propagation Delays
    − 50% Lower Quiescent Power
    − Improved Input Noise and Latchup Immunity
• These are Pb−Free Devices