ADE9178 datasheet(35/122 Pages) AD

35 / 122 page

Data Sheet

ADE9178

THEORY OF OPERATION

analog.com

Rev. A | 35 of 122

ADE9178 DATA PROCESSING FLOW

This section explains the processing done on the ADC data re-

ceived before calculating various parameters.

Current-Channel Data Processing Path

The ADE9178 has three current channels. The datapaths for the

AI, BI, and CI current channels is shown in Figure 46. Write to the

ICONSEL bit in the CONFIG0 register to calculate BI = −AI − CI.

This setting can help to save the cost of a current sensor in some

3-wire delta configurations. Waveform data can be streamed to the

Host MCU directly from the ADC samples or from after the PCF.

WF_SRC[6:5] bits in the WFS_CONFIG register configures which

data is streamed.

Figure 46. Current-Channel Datapath

Voltage-Channel Data Processing Path

The ADE9178 has three voltage channels. The datapaths for the

AV, BV, and CV voltage channels is shown in Figure 47. VCON-

SEL[2:0] field of CONFIG0 register can be used to configure the

channels for different meter configurations such as Wye and Delta.

Same as the current channel, WF_SRC[6:5] bits in the WFS_CON-

FIG register can be used to configure which data is streamed to the

Host MCU.

Figure 47. Voltage-Channel Datapath

Auxiliary-Channel Data Processing Path

The ADE9178 supports six auxiliary channels. This can be used

for various other measurements including neutral current measure-

ments or additional voltages. The datapath for auxiliary channels

are shown in Figure 48. Same as the current and voltage channel,

WF_SRC[6:5] bits in the WFS_CONFIG register can be used to

configure which data is streamed to the Host MCU.

Figure 48. Auxiliary-Channel Datapath

Common-Data Processing Path

Figure 49 shows the common datapath.

Figure 49. Common Datapath

Gain and Offset Compensation

All channels support gain and offset compensation. Separate regis-

ters are provided for each channel

xINP= xINP0+xOS × 1+xGAIN227 (18)

where, xINP0 is the initial input value before applying gain and

offset calibration.

Note that xOS is typically not used for AC metering applications.

For worked examples, see the Calibration Method section.

Calibration Registers Clamp Values

Table 15 shows the range of adjustment for each calibration regis-

ter. Any value that is outside of the ranges given in Table 15 is

clamped to the maximum or minimum value.

ADE9178 数据表(PDF) 35 Page - Analog Devices

ADE9178 数据表(HTML) 35 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 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

数据表下载