ADE7933 datasheet(44/125 Pages) AD

44 / 125 page

ADE7978/ADE7933/ADE7932/ADE7923

Data Sheet

Rev. D | Page 44 of 125

CHANGING THE PHASE VOLTAGE DATAPATH

The ADE7978 can direct one phase voltage input to the compu-

tational datapath of another phase. For example, the Phase A

voltage can be introduced into the Phase B computational data-

path, which means that all powers computed by the ADE7978

in Phase B are based on the Phase A voltage and the Phase B

current. Table 18 lists the settings of the VTOIA[1:0] bits and

the configured phase voltage directed to the Phase A

computational datapath.

Table 18. VTOIA[1:0] Bit Settings (CONFIG Register,

Bits[9:8])

VTOIA[1:0] Bits

Voltage Directed to the Phase A

Computational Datapath

00 (Default)

Phase A voltage

Phase B voltage

Phase C voltage

Phase A voltage

Table 19 lists the settings of the VTOIB[1:0] bits and the configured

phase voltage directed to the Phase B computational datapath.

Table 19. VTOIB[1:0] Bit Settings (CONFIG Register,

Bits[11:10])

VTOIB[1:0] Bits

Voltage Directed to the Phase B

Computational Datapath

00 (Default)

Phase B voltage

Phase C voltage

Phase A voltage

Phase B voltage

Table 20 lists the settings of the VTOIC[1:0] bits and the con-

figured phase voltage directed to the Phase C computational

datapath.

Table 20. VTOIC[1:0] Bit Settings (CONFIG Register,

Bits[13:12])

VTOIC[1:0] Bits

Voltage Directed to the Phase C

Computational Datapath

00 (Default)

Phase C voltage

Phase A voltage

Phase B voltage

Phase C voltage

Figure 58 shows the Phase A voltage used in the Phase B data-

path, the Phase B voltage used in the Phase C datapath, and the

Phase C voltage used in the Phase A datapath.

PHASE A

COMPUTATIONAL

DATAPATH

PHASE B

COMPUTATIONAL

DATAPATH

PHASE C

COMPUTATIONAL

DATAPATH

VTOIA[1:0] = 10,

PHASE C VOLTAGE

DIRECTED

TO PHASE A

VTOIB[1:0] = 10,

PHASE A VOLTAGE

DIRECTED

TO PHASE B

VTOIC[1:0] = 10,

PHASE B VOLTAGE

DIRECTED

TO PHASE C

CPHCAL

BPHCAL

APHCAL

Figure 58. Phase Voltages Used in Different Datapaths

REFERENCE CIRCUITS

The nominal reference voltage at the REF pin of the ADE7933/

ADE7932 and ADE7923 is 1.2 V. This reference voltage is used

for the ADCs. Because the on-chip dc-to-dc converter in the

ADE7933/ADE7932 cannot supply external loads, the REF pin

cannot be overdriven by a standalone external voltage reference.

The ADE7923 does not have an on-chip dc-to-dc converter.

The voltage of the ADE7933/ADE7932 and ADE7923 reference

drifts slightly with temperature. Table 6 and Table 10 specify the

gain drift over temperature for each ADC channel. The gain drift

includes the temperature variation of the ADC gain, together

with the temperature variation of the internal voltage reference.

The value of the gain temperature drift varies from device to

device.

Because the energy calculation uses two ADC channels, one for

the current and one for the voltage, any x% drift in the gain results

in a 2x% deviation of the meter accuracy. The reference drift

resulting from temperature changes is usually very small and is

typically much smaller than the drift of other components on a

meter. As an alternative, the meter can be calibrated at multiple

temperatures.

The VA2, VB2, VC2, and VN2 voltages and the temperature

sensor use the third ADC of the ADE7933/ADE7932 and

ADE7923, so any x% drift in the gain results in an x% deviation of

these measurements.

ADE7933 数据表(PDF) 44 Page - Analog Devices

ADE7933 数据表(HTML) 44 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

链接网址

ADE7933 数据表(PDF) 44 Page - Analog Devices

ADE7933 数据表(HTML) 44 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

链接网址

数据表下载