ADE9000ACPZ datasheet(26/73 Pages) AD

26 / 73 page

Data Sheet

ADE9000

Rev. A | Page 25 of 72

TERMINOLOGY

Crosstalk

Crosstalk is measured by grounding one channel and applying a

full-scale 50 Hz or 60 Hz signal on all the other channels. The

crosstalk is equal to the ratio between the grounded ADC output

value and its ADC full-scale output value. The ADC outputs

are acquired for 100 sec. Crosstalk is expressed in decibels.

Differential Input Impedance (DC)

The differential input impedance represents the impedance

between the pair IxP and IxN or VxP and VxN. It varies with

the PGA gain selection as indicated in Table 1.

ADC Offset

ADC offset is the difference between the average measured

ADC output code with both inputs connected to GND and the

ideal ADC output code of zero. ADC offset is expressed in mV.

ADC Offset Drift over Temperature

The ADC offset drift is the change in offset over temperature.

It is measured at −40°C, +25°C, and +85°C. Calculate the offset

drift over temperature as follows:

(

)

(

)

(

)

(

)

(

)

(

)

















−

max

Offset

Drift

Offset drift is expressed in µV/°C.

ADC Gain Error

The gain error in the ADCs represents the difference between the

measured ADC output code (minus the offset) and the ideal

output code when an external voltage reference of 1.2 V is used.

The difference is expressed as a percentage of the ideal code. It

represents the overall gain error of one channel.

ADC Gain Drift over Temperature

This temperature coefficient includes the temperature variation

of the ADC gain while using an external voltage reference of

1.2 V. It represents the overall temperature coefficient of one

current or voltage channel. With an external voltage reference

of 1.2 V in use, the ADC gain is measured at −40°C, +25°C, and

+85°C. Then the temperature coefficient is computed as follows:

(

)

(

)

(

)

(

)

(

)

(

) 















−

(

max

Gain

Drift

Gain drift is measured in ppm/°C.

AC Power Supply Rejection (PSRR)

AC PSRR quantifies the measurement error as a percentage of

reading when the dc power supply is nominal (VNOM) and

modulated with ac, and the inputs are grounded. For the ac PSRR

measurement, 20 sec samples are captured with nominal supplies

(3.3 V, which is V1) and a second set (V2) is captured with an

additional ac signal (330 mV peak at 50 Hz) introduced onto the

supplies. Then, the PSRR is expressed as PSRR = 20 log10(V2/V1).

Signal-to-Noise Ratio (SNR)

SNR is calculated by inputting a 50 Hz signal, and samples are

acquired for 2 sec. The amplitudes for each frequency up to the

bandwidth given in Table 1 as the ADC output bandwidth (−3 dB)

are calculated. To determine the SNR, the signal at 50 Hz is

compared to the sum of the power from all the other frequencies,

removing power from its harmonics. The value for SNR is

expressed in decibels.

Signal-to-Noise-and-Distortion Ratio (SINAD)

SINAD is calculated by inputting a 50 Hz signal, and samples

are acquired for 2 sec. The amplitudes for each frequency up to

the bandwidth given in Table 1 as the ADC output bandwidth

(−3 dB) are calculated. To determine the SINAD, the signal at

50 Hz is compared to the sum of the power from all the other

frequencies. The value for SINAD is expressed in decibels.

Total Harmonic Distortion (THD)

THD is calculated by inputting a 50 Hz signal, and samples are

acquired for over 2 sec. The amplitudes for each frequency up

to the bandwidth given in Table 1 as the ADC output bandwidth

(−3 dB) are calculated. To determine the THD, the amplitudes

of the 50 Hz harmonics up to the bandwidth are root sum

squared. The value for THD is expressed in decibels.

Spurious-Free Dynamic Range (SFDR)

SFDR is calculated by inputting a 50 Hz signal, and samples are

acquired for over 2 sec. The amplitudes for each frequency up

to the bandwidth given in Table 1 as the ADC output bandwidth

(−3 dB) are calculated. To determine the SFDR, the amplitude

of the largest signal that is not a harmonic of 50 Hz is recorded.

The value for SFDR is expressed in decibels.

ADC Output Pass Band

The ADC output pass band is the bandwidth within 0.1 dB,

resulting from the digital filtering in the sinc4 and sinc4 + IIR LPF.

ADC Output Bandwidth

The ADC output bandwidth is the bandwidth within −3 dB,

resulting from the digital filtering in the sinc4 and sinc4 + IIR LPF.

ADE9000ACPZ Fiches technique(PDF) 26 Page - Analog Devices

ADE9000ACPZ Fiches technique(HTML) 26 Page - Analog Devices

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73

Fiches technique Télécharger

Lien URL