SN74ACT00: Operation with PWM input signal

Naveen Bevara

Intellectual 1970 points

Part Number: SN74ACT00

Hi Team,

If the input is a PWM signal operating with a particular frequency, will the IC add any error or distortion in frequency and impact the duty cycle of operation while generating the output?

Is the pulse width distortion parameter available for IC?

Please confirm if the IC affects the signal frequency and duty cycle of operation.

Regards,
Naveen

over 4 years ago

0 Rami Mooti1 over 4 years ago

TI__Mastermind 35638 points

Hey Naveen,

There will be some variation in the output relative to the input but how much and if this will be an issue will depend a bit on the setup. Without knowing anything about the inputs, such as the voltage level or frequency and tolerances you may have I couldn't give you a definitive answer.
I can say there will be some delay and ramp up time that may vary from your input by adding the gate. How quickly the output ramps up and any propagation delay associated will depend on the drive strength that can be found in the datasheet and the load of the system.
Here are a couple of good FAQ's we've created that may help you.

[FAQ] What is the output transition rate for a logic device?

[FAQ] What is the maximum capacitive load that a logic device can drive?

Thanks,
Rami

0 Prachi Moghe over 4 years ago in reply to Rami Mooti1

Prodigy 110 points

Hi Rami,

The gate is driven by 5V and 10kHz signal. The frequency tolerance is ±5kHz. The load is approximately 270 Ω.

Let's say duty cycle is 50%. Due to IC's internal parameter, how much it can vary ? How do I calculate this distortion in duty cycle ? Will this also affect the frequency ?

Please help me understand the frequency and duty cycle distortion due to IC.

Regards,

Prachi

0 Clemens Ladisch over 4 years ago in reply to Prachi Moghe

Guru 317370 points

If we assume the worst cases for the propagation delays from the datasheet, under the specified test conditions, the pulse width distortion is less than 8.5 ns. The actual value is expected to be less than 1 ns. (5 kHz corresponds to 100000 ns).

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SN74ACT00: Operation with PWM input signal