74HC390 Dual 4-bit Decade Ripple Counter
A versatile dual counter with multiple counting configurations
- Supply Voltage (VCC): 0.5 to +7.0V
- Clamp Diode Current (IIK, IOK): ±20 mA
- DC VCC or GND Current, per pin (ICC): ±50 mA
- Storage Temperature Range (TSTG): -65°C to +150°C
- Power Dissipation (PD): 500 mW
- Lead Temperature (TL) (Soldering 10 seconds): 260°C
Features:
- CMOS level input levels
- Two BCD decade or bi-quinary counters
- Can be configured to divide-by-2, 4, 5, 10, 20, 25, 50, or 100
- Two master reset inputs to clear each decade counter individually
The 74HC390 is a dual 4-bit decade ripple counter divided into four separately clocked sections. It offers various counting configurations within one package by utilizing master reset inputs 1MR and 2MR. The section clocks, nCP0 and nCP1, enable ripple counter or frequency division applications. The HIGH-to-LOW transition of the clock inputs triggers each section. It can operate in BCD decade or bi-quinary configuration, offering flexibility in usage.
For BCD decade operation, the nQ0 output connects to the nCP1 input of the divide-by-5 section. In bi-quinary decade operation, the nQ3 output connects to the nCP0 input, and nQ0 becomes the decade output. The nMR input, when HIGH, overrides the clocks and sets all outputs LOW. Input levels are specified as CMOS level, with ESD protection exceeding 2000V for HBM and 200V for MM.
The presence of clamp diodes allows for the use of current limiting resistors to interface inputs to voltages exceeding VCC, enhancing overall protection and versatility.
Images are for illustration only; actual product may vary.