1. General description
The 74HC594; 74HCT594 is an 8-bit serial-in/serial or parallel-out shift register with a storage
register. Separate clock and reset inputs are provided on both shift and storage registers. The
device features a serial input (DS) and a serial output (Q7S) to enable cascading. Data is shifted
on the LOW-to-HIGH transitions of the SHCP input, and the data in the shift register is transferred
to the storage register on a LOW-to-HIGH transition of the STCP input. If both clocks are
connected together, the shift register will always be one clock pulse ahead of the storage register.
A LOW level on one of the two register reset pins (SHR and STR) will clear the corresponding
register. Inputs include clamp diodes. This enables the use of current limiting resistors to interface
inputs to voltages in excess of VCC.
2. Features and benefits
• Synchronous serial input and output
• 8-bit parallel output
• Shift and storage registers have independent direct clear and clocks
• Independent clocks for shift and storage registers
• 100 MHz (typical)
• Wide supply voltage range from 2.0 V to 6.0 V
• CMOS low power dissipation
• High noise immunity
• Latch-up performance exceeds 100 mA per JESD 78 Class II Level B
• Input levels:
• For 74HC594: CMOS level
• For 74HCT594: TTL level
• Complies with JEDEC standards
• JESD8C (2.7 V to 3.6 V)
• JESD7A (2.0 V to 6.0 V)
• ESD protection:
• HBM JESD22-A114F exceeds 2 kV
• MM JESD22-A115-A exceeds 200 V (C = 200 pF, R = 0 Ω)
• Multiple package options
• Specified from -40 °C to +85 °C and from -40 °C to +125 °C
3. Applications
• Serial-to parallel data conversion
• Remote control holding register