Dual 4-bit Decade Ripple Counter IC - 74HC390
Dual 4-bit Decade Ripple Counter IC - 74HC390 The 74HC Series 74HC390 IC is a 16 Pin Dual 4-bit Decade Ripple Counter IC having a 2V to 6V Operating Voltage range. It has been divided into four separately clocked sections. The counters have two divide-by-2 sections and two divide-by-5 sections. These sections share an asynchronous master reset input (nMR) and can be used in a BCD decade or bi-quinary configuration. If master reset inputs 1MR and 2MR are used to clear all 8 bits of the counter simultaneously, numerous counting configurations are possible within one package. Section clocks nCP0 and nCP1, allow ripple counter or frequency division applications of divide-by-2, 4, 5, 10, 20, 25, 50 or 100. The HIGH-to-LOW transition of the clock inputs nCP0 and nCP1 triggers each section. For BCD decade operation, the nQ0 output is connected to the nCP1 input of the divide-by-5 section. For bi-quinary decade operation, the nQ3 output is connected to the nCP0 input and nQ0 becomes the decade output. A HIGH on the nMR input overrides the clocks and sets the four outputs LOW. Inputs include clamp diodes. It enables the use of current-limiting resistors to interface inputs to voltages in excess of VCC. Pinout: Pinout Of 74HC390 IC Symbol Pin Description 1CP0, 2CP0 1, 15 Clock input divide-by-2 section (HIGH-to-LOW; edge-triggered) 1MR, 2MR 2, 14 Asynchronous master reset input (active HIGH) 1Q0, 1Q1, 1Q2, 1Q3 3, 5, 6, 7 Flip-flop outputs 1CP1, 2CP1 4, 12 Clock input divide-by-5 section (HIGH-to-LOW; edge-triggered) GND 8 Ground (0 V) 2Q0, 2Q1, 2Q2, 2Q3 13, 11, 10, 9 Flip-flop output VCC 16 Supply voltage
- DC Input Diode Current: ±20mA
- Frequency: 71MHz
- Output Drive Capability: 10 LSTTL Loads
- Outputs Directly Interface to CMOS, NMOS, and TTL
- Low Input Current: 1 μA
- High Noise Immunity Characteristic of CMOS Devices
- Operating Voltage Range 2.0 to 6.0 V
- Package DIP?16
- Input Current 1 uA
- Powering Current 160 uA
- Output Current at VCC 4 mA
- Fan-Out 10 LS-TTL Load
- Propagation Delay 14 ns
- Temperature Range -65 °C to +150 °C