The maximum clock frequency of the SN74LS90NSR is typically around 2-3 MHz, but it can vary depending on the specific application and operating conditions. It's recommended to check the device's timing specifications and perform thorough testing to ensure reliable operation at the desired clock frequency.
To ensure proper power supply and decoupling, connect the VCC pin to a stable 5V power supply, and decouple the power supply lines with 0.1uF ceramic capacitors as close to the device as possible. Additionally, use a 10uF electrolytic capacitor in parallel with the 0.1uF capacitor to filter out low-frequency noise.
The recommended operating temperature range for the SN74LS90NSR is 0°C to 70°C. However, the device can operate up to 85°C with reduced performance and reliability. It's essential to ensure that the device is operated within the recommended temperature range to maintain its performance and lifespan.
The asynchronous reset input (R) of the SN74LS90NSR should be connected to a pull-up resistor (typically 1kΩ to 10kΩ) to ensure that the device is properly reset. The reset input should be driven low to reset the device, and then released to allow the device to operate normally.
The maximum output current that the SN74LS90NSR can sink or source is typically around 16mA per output pin. However, it's recommended to limit the output current to 10mA or less to ensure reliable operation and prevent overheating.
SN74LS90NSR datasheet
by Texas Instruments
