# Analog System Response Time

## Overview​

The analog response time is the time it takes from when an analog input changes to when a responding analog output changes. This total response time can be broken down into several parts as an analog input goes into the Quarto and makes it way to an analog output:

1. DAC Update Time
2. Analog Output Filter
5. Interrupt Latency
6. MCU Processing Time

### DAC Update Time​

The DAC Measurement Time is 1µs2.

### Analog Output Filter​

The output filter between the DAC and the Quarto's Analog Output has a bandwidth of 180 kHz2. While this filter isn't a simple delay circuit, as the delay varies for different frequency components, for frequencies at 100 kHz or below, the delay is 1.2µs.

The input filter in front of the Analog Input has a bandwidth of 400 kHz. While this filter isn't a simple delay circuit, as the delay varies for different frequency components, for frequencies at 100 kHz or below, the delay is 550ns.

The ADC Measurement Time is 800ns1.

### Interrupt Latency​

Please see Measuring Interrupt Latency App Note note for details, but the worst-case interrupt latency is 210ns.

### MCU Processing Time​

Clearly this depends on the function that that is executing. In the Measuring Interrupt Latency App Note the processing time was only 160ns. More complex functions will take longer to run. If unsure how long something takes to execute, as done in the app note, can you use a trigger line to measure the execution time with an O-scope. The code would be:

triggerWrite(1,HIGH); // Set Trigger 1 high at start on functionfunctiontoTime();triggerWrite(1,LOW); // Set Trigger 1 low after function completes

But for straight-forward arithmetic functions (no loops), 500ns is a safe estimate.