Overview
The MC74ACT161, produced by onsemi, is a high-speed synchronous modulo-16 binary counter. This component is part of the MC74AC161/74ACT161 and MC74AC163/74ACT163 series, which are designed for synchronous counting and loading. It is particularly useful in applications requiring programmable dividers and synchronous multistage counters. The MC74ACT161 features an asynchronous Master Reset input, which overrides all other inputs and forces the outputs LOW, making it versatile for various digital circuit designs.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| VCC (DC Supply Voltage) | 4.5 | 5.0 | 5.5 | V |
| VI (DC Input Voltage) | 0 | - | VCC + 0.5 | V |
| VO (DC Output Voltage) | 0 | - | VCC + 0.5 | V |
| fmax (Maximum Count Frequency) | 115 | 125 | - | MHz |
| tPLH (Propagation Delay CP to Qn) | 1.5 | 8.0 | 9.5 | ns |
| tPHL (Propagation Delay CP to Qn) | 1.5 | 8.0 | 10.5 | ns |
| IOH (Output Current High) | -24 | - | - | mA |
| IOL (Output Current Low) | 24 | - | - | mA |
| TA (Operating Ambient Temperature Range) | -40 | - | 85 | °C |
Key Features
- Synchronous Counting and Loading: The MC74ACT161 supports synchronous counting and loading, making it suitable for applications requiring precise timing and synchronization.
- High-Speed Synchronous Expansion: With a typical count rate of 125 MHz, this component is ideal for high-speed applications.
- TTL Compatible Inputs: The ACT161 has TTL compatible inputs, ensuring compatibility with a wide range of digital circuits.
- Asynchronous Master Reset: The MC74ACT161 features an asynchronous Master Reset input that overrides all other inputs and forces the outputs LOW.
- Terminal Count Output: The component includes a Terminal Count output, which is HIGH when the counter is in state 15, facilitating the formation of synchronous multistage counters.
- Count Enable Inputs: It has two types of Count Enable inputs (CEP and CET) for versatile counting control.
- Pb-free Packages: Available in Pb-free packages, making it compliant with environmental regulations.
Applications
- Programmable Dividers: The MC74ACT161 is particularly useful in programmable divider applications due to its synchronous presettable feature.
- Synchronous Multistage Counters: It is designed for forming synchronous multistage counters, making it ideal for complex digital circuit designs.
- High-Speed Digital Circuits: Its high-speed capabilities make it suitable for use in high-speed digital circuits and systems.
- Timing and Synchronization: The component is useful in applications requiring precise timing and synchronization, such as in telecommunications and data processing systems.
Q & A
- What is the maximum count frequency of the MC74ACT161?
The maximum count frequency of the MC74ACT161 is 125 MHz.
- What type of reset does the MC74ACT161 have?
The MC74ACT161 has an asynchronous Master Reset input.
- Is the MC74ACT161 TTL compatible?
Yes, the MC74ACT161 has TTL compatible inputs.
- What is the purpose of the Terminal Count output?
The Terminal Count output is HIGH when the counter is in state 15, facilitating the formation of synchronous multistage counters.
- What are the Count Enable inputs on the MC74ACT161?
The MC74ACT161 has two Count Enable inputs: Count Enable Parallel (CEP) and Count Enable Trickle (CET).
- What is the operating ambient temperature range of the MC74ACT161?
The operating ambient temperature range is from -40°C to 85°C.
- Does the MC74ACT161 come in Pb-free packages?
Yes, the MC74ACT161 is available in Pb-free packages.
- What is the typical output current of the MC74ACT161?
The outputs can source/sink up to 24 mA.
- How many control inputs does the MC74ACT161 have?
The MC74ACT161 has five control inputs: Master Reset (MR), Parallel Enable (PE), Count Enable Parallel (CEP), Count Enable Trickle (CET), and Synchronous Reset (SR) for the MC74AC163/74ACT163.
- What is the setup time for the parallel data inputs relative to the clock input?
The setup time for the parallel data inputs (Pn) relative to the clock input (CP) is typically 6.0 ns for VCC at 3.3 V and 3.5 ns for VCC at 5.0 V.
