1. General description
The 74HC590 is an 8-bit binary counter with a storage register and 3-state outputs. The storage
register has parallel (Q0 to Q7) outputs. The binary counter features master reset counter (MRC)
and count enable (CE) inputs. The counter and storage register have separate positive edge
triggered clock (CPC and CPR) inputs. If both clocks are connected together, the counter state is
always one count ahead of the register. Internal circuitry prevents clocking from the clock enable.
A ripple carry output (RCO) is provided for cascading. Cascading is accomplished by connecting
RCO of the first stage to CE of the second stage. Cascading for larger count chains can be
accomplished by connecting RCO of each stage to the counter clock (CPC) input of the following
stage. 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
• 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
• Complies with JEDEC standards:
• JESD8C (2.7 V to 3.6 V)
• JESD7A (2.0 V to 6.0 V)
• CMOS input levels
• Counter and register have independent clock inputs
• Counter has master reset
• Multiple package options
• ESD protection:
• HBM JESD22-A114F exceeds 2000 V
• MM JESD22-A115-A exceeds 200 V
• CDM JESD22-C101C exceeds 1000 V
• Specified from -40 °C to +85 °C and from -40 °C to +125 °C