## How do you calculate switching frequency of PWM?

1 Answer

- τ=LR.
- τ=1f.
- f>1L/R.

### What is a prescaler value?

A prescaler divides down the clock signals used for the timer, giving reduced overflow rates. The rate can be set to a number of possible values. The prescaler value is used in conjunction with the clock speed to set an overflow frequency, e.g.: • Clock speed: 19660800.

#### What is Fast PWM?

Fast PWM. In the simplest PWM mode, the timer repeatedly counts from 0 to 255. The output turns on when the timer is at 0, and turns off when the timer matches the output compare register. The higher the value in the output compare register, the higher the duty cycle. This mode is known as Fast PWM Mode.

**How do you calculate microcontroller speed?**

First thing you need to know is how many cycles it takes the microcontroller to execute this code. Again, you need to consult the data sheet of the micro….Hypothetical numbers:

- Load takes 3 cycles.
- Load from PortA adds 2 cycles overhead.
- Add takes 1 cycle.
- Store takes 2 cycles.
- Store to PortB adds 4 cycles overhead.

**How do you calculate a tick count?**

Calculate the base tick value by dividing the Product’s numerator by the denominator.

## What is PWM unit in atmega16/32?

AVR-based ATmega16/32 has inbuilt Pulse Width Modulation (PWM) unit through which the width of a pulse is varied while keeping the frequency constant. Your browser does not support JavaScript!

### How to calculate the frequency of a PWM signal?

In every PWM period counter must count 256 steps, so frequency of signal is 256 times lower than counter clock from prescaler. PWM frequency = Atmega clock frequency/timer prescaler (1,8,32,64,128,256)/256.

#### How to get 31 kHz PWM?

Assuming you don’t care about the specific frequency, but just want it out of the audible range, you can easily get 31 kHz PWM on pin 9 and 10 (controlled by Timer1) and / or 11 and 3 (controlled by Timer2).

**What is the PWM frequency of 4 MHz crystal?**

PWM frequency = Atmega clock frequency/timer prescaler (1,8,32,64,128,256)/256. With 4 MHz crystal maximum (without prescaler) PWM frequency is 15 625Hz. For example 15 625 Hz, 50 % duty cycle, non-inverting mode PWM signal generation. 1. OCR2=0x80 (128); As mentioned before duty cycle = OCR2/256*100% 2. TCCR2=0x69; 3.