ADE7758ARWRL datasheet(53/68 Pages) AD

53 / 68 page

ADE7758

Rev. A | Page 53 of 68

STEP 1

SET

CONFIGURATION

REGISTERS FOR

ZERO CROSSING

ON ALL PHASES

STEP 2

SET INTERRUPT

MASK FOR

ZERO CROSSING

ON ALL PHASES

STEP 3

STEP 4

READ RMS

REGISTERS

STEP 5

WRITE TO

XVRMSOS

XIRMSOS

SET UP

SYSTEM FOR

ITEST, VNOM

SET UP

SYSTEM FOR

IMAX/500, VNOM

SET UP SYSTEM

FOR ITEST,

VNOM/20

START

TESTED

ALL

PHASES?

YES

TESTED

ALL

CONDITIONS?

STEP 4A

CHOOSE N

n = 0

STEP 4D

READ

XIRMS

XVRMS

STEP 4E

CALCULATE THE

AVERAGE OF N

SAMPLES

STEP 4B

RESET INTERRUPT

STATUS REGISTER

END

n = n + 1

n = N?

YES

STEP 4C

INTERRUPT?

Figure 84. RMS Calibration Routine

Step 1: Set configuration registers for zero crossings on all

phases by writing the value 0x38 to the LCYCMODE register

(0x17). This sets all of the ZXSEL bits to Logic 1.

Step 2: Set the interrupt mask register for zero-crossing

detection on all phases by writing 0xE00 to the MASK[0:24]

Step 3: Set up the calibration system for one of the three test

conditions: ITEST and VNOM, IMAX/500 and VNOM, ITEST and VNOM/20.

Step 4: Read the rms registers after the zero-crossing interrupt

and take an average of N samples. This is recommended to get

the most stable rms readings. This procedure is detailed in

Figure 84—Steps 4a through 4e.

Step 4a. Choose the number of samples, N, to be averaged.

Step 4b. Reset the interrupt status register by reading RSTATUS

(0x1A).

Step 4c. Wait for the zero-crossing interrupt. When the zero-

crossing interrupt occurs, move to Step 4d.

Step 4d. Read the xIRMS (0x0A) and xVRMS (0x0C) registers.

These values will be averaged in Step 4e.

Step 4e: Average the N samples of xIRMS and xVRMS. The

averaged values will be used in Step 5.

Step 5: Write to the xVRMSOS (0x36 to 0x38) and xIRMSOS

(0x33 to 0x35) registers according to the following equations.

IRMSOS

(

)(

)

–

384

TEST

MAX/X

RMS

TEST

MAX/X

RMS

MAX/X

TEST

−

(56)

where ITEST-RMS and IMAX/X-RMS are the rms register values without

the offset correction for the input ITEST and IMAX/X, respectively.

NOM

NOM/20

RMS

NOM

NOM/20

RMS

NOM/20

NOM

VRMSOS

–

−

(57)

where VNOM-RMS and VNOM/20-RMS are the rms register values

without the offset correction for the input VNOM and VNOM/20-RMS,

respectively.

ADE7758ARWRL 数据表(PDF) 53 Page - Analog Devices

ADE7758ARWRL 数据表(HTML) 53 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

数据表下载

链接网址

ADE7758ARWRL 数据表(PDF) 53 Page - Analog Devices

ADE7758ARWRL 数据表(HTML) 53 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

数据表 下载

链接网址

数据表下载