## How do you measure ADC SFDR?

To measure the SFDR of a signal generator, a tone is generated at a given frequency. A spectrum analyzer is then used to measure the amplitude of the fundamental tone and the amplitude of the next highest tone.

SNR is a calculated value that represents the ratio of rms signal to rms noise. You then multiply the log10 of this ratio by 20 to derive SNR in decibels. As I mention above, an ADC’s ideal SNR equals 6.02N+1.76 dB, where N is the number of bits.

ENOB is based on the equation for an ideal ADC’s SNR: SNR = 6.02 × N + 1.76 dB, where N is the ADC’s resolution. A real world ADC never achieves this SNR due to its own noise and errors. You can rearrange the equation to calculate an ADC’s effective N, or ENOB as we commonly call it: ENOB = (SNR – 1.76)/6.02 dB.

### What is SFDR in dB of the receiver?

The Spurious-Free Dynamic Range (SFDR) of a receiver is a ratio of the amplitude of the fundamental carrier signal to the amplitude of the strongest spurious signal in the frequency range of interest. SFDR is usually measured in dBc (i.e. with respect to the carrier signal amplitude).

How do you calculate SFDR?

General use of DB, expressed as: SFDR=Ps-Pn, SFDR is the spurious-free dynamic range ( dB ), Ps is a useful signal power ( dBm ), Pn is the largest clutter signal power value ( dBm ).

What is THD N ratio?

Total harmonic distortion plus noise (THD + N) is the ratio of the rms value of the fundamental signal to the mean value of the root-sum-square of its harmonics plus all noise components (excluding dc). The bandwidth over which the noise is measured must be specified.

#### How is ADC noise calculated?

Calculate 10 × log (fSAMPLE/2) = 10 × log (65Msps/2) = 75.1dB. The converter’s normalized Nyquist band noise power is found by subtracting 75.1dB from -66dBm resulting in -141.1dBm in a 1Hz bandwidth. The resulting effective ADC noise figure = -141.1dBm – KTB = -141.1dBm – (-174dBm) = 32.9dB.

What is the SNR of 16-bit ADC?

80 dBfs
16-Bit ADC Specs 80 dBfs SNR.

What is noise floor in RF?

In signal theory, the noise floor is the measure of the signal created from the sum of all the noise sources and unwanted signals within a measurement system, where noise is defined as any signal other than the one being monitored.

## Who does SFDR apply?

The SFDR regulation applies to FMPs such as investment firms, pension funds, asset managers, insurance companies, banks, venture capital funds, credit institutions offering portfolio management, or financial advisors.

How do you measure THD N?

THD N can be expressed as an absolute value. However, it is more common to use the THD N ratio, which will compare it to the input signal. The ratio is expressed as either a percentage or as a decibel. For the percentage, it is calculated by the THD N divided by the total signal level.

How do you calculate THD N?

Total Harmonic Distortion Plus Noise The notch filter removes the fundamental sine signal, leaving a residual signal which consists of the harmonics and noise. The THD+N Ratio is calculated as the bandwidth limited rms level of the residual divided by the rms level of the entire signal.

### How to calculate the SFDR of an ADC?

Having the maximum and minimum signal levels at the ADC input , we can calculate the SFDR of the ADC. We only need to make an assumption about the level of the allowed distortion component. Let’s assume that the distortion component should be 18 dB below the smallest signal that can appear at the ADC input. This is depicted in Figure 5.

What should be considered when choosing a wideband ADC?

Many analog input specifications should be considered when selecting a wideband analog-to-digital converter (ADC) for a high performance system, such as ADC resolution, sample rate, signal-to-noise ratio (SNR), effective number of bits (ENOB), input bandwidth, spurious free dynamic range (SFDR), and differential or integral nonlinearity.

What should the SNR be for an ADC?

Assume that our wireless standard mandates having an SNR of about 9 dB at the ADC input to detect the desired signal with an acceptable quality. In other words, if the SNR goes below 9 dB, we’ll have an unacceptable bit error rate. Hence, as shown in Figure 6, the total noise power at the ADC input should be less than -84 dBm.

#### What is the dynamic range of a 12 bit ADC?

This is an FFT of a monolithic 12-bit ADC that shows the third harmonic as the dominant contributor to SFDR. In this case, the dynamic range from the fundamental (–1 dBFS) to the third harmonic (–82 dBFS) is –81 dBc, since it is relative to the carrier power.

How do you measure ADC SFDR? To measure the SFDR of a signal generator, a tone is generated at a given frequency. A spectrum analyzer is then used to measure the amplitude of the fundamental tone and the amplitude of the next highest tone. How is ADC SNR measured? SNR is a calculated value that…