The 74HC161 is a synchronous presettable binary counter with an internal look-ahead carry. This device ensures synchronous operation by clocking all flip-flops simultaneously on the positive-going edge of the clock (CP). The outputs (Q0 to Q3) can be preset to HIGH or LOW. A LOW signal at the parallel enable input (PE) disables counting and loads the data from the inputs (D0 to D3) into the counter on the clock's positive edge. This preset operation occurs regardless of the levels at the count enable inputs (CEP and CET). A LOW signal at the master reset input (MR) asynchronously clears the counter, setting Q0 to Q3 to LOW.
The look-ahead carry feature simplifies the serial cascading of counters. Both CEP and CET inputs must be HIGH for counting to occur. The CET input enables the terminal count output (TC), which produces a HIGH output pulse approximately equal to a HIGH output of Q0, useful for enabling the next cascaded stage. The maximum clock frequency for cascaded counters is determined by the CP to TC propagation delay and the CEP to CP setup time.
Features:
- Wide supply voltage range: 2.0V to 6.0V
- CMOS low power dissipation
- High noise immunity
- Latch-up performance exceeds 100 mA per JESD 78 Class II Level B
- CMOS input levels
- Synchronous counting and loading
- Two count enable inputs for n-bit cascading
- Asynchronous reset
- Positive-edge triggered clock
- ESD protection:
- HBM JESD22-A114F exceeds 2000V
- MM JESD22-A115-A exceeds 200V
- Specified operating temperature range: -40°C to 85°C and -40°C to 125°C
Specifications:
- Supply Voltage: -0.5V to 7.0V
- Input Clamp Current: 20 mA
- Output Clamp Current: 20 mA
- Output Current: 25 mA
- Supply Current: 50 mA
- Ground Current: -50 mA
- Storage Temperature: -65°C to 150°C
- Total Power Dissipation: 500 mW
Package Includes:
1 x 74HC161 - 4-Bit Presettable Synchronous Binary Counter IC - SOIC-16 SMD Package
Note: Product images are for illustrative purposes only and may differ from the actual product.
