–3–

PRELIMINARY TECHNICAL DATA

REV. PrF

EVAL-ADE7757EB

50Hz

220V

SK1B

50Hz

30mV

SK1A

SK1C

V2P

V2N

JP6

C18

R20

JP7

R18

C19

TP5

JP5

R19

R15

A

B

JP17

R21

R22

N

P

JP16

N

P

JP9

JP8

SK2A

SK2B

TP4

C16

TP1

V1P

JP1

JP2

R16

C17

TP2

V1N

JP3

JP4

R17

JP18

AGND

Figure 4. Typical Connection for Analog Inputs

LOGIC OUTPUTS

ADE7757 provides the active power information in the

form of an output frequency. The three frequency outputs

are F1, F2 and CF. Consult the datasheet for more infor-

mation on these outputs. The logic outputs F1 and F2 are

intended to be used to drive an impulse counter or stepper

motor. The outputs are buffered and available at the con-

nector SK6. A stepper motor may be directly connected

here. The power supply for the buffer is +5V (SK4A) and

may be connected to the ADE7757 supply using jumper

JP15, or to its own supply.

The logic output CF can be directly connected to an LED

using JP14 (Position B) or to an optically isolated output (Posi-

tion A). By closing Positions A and B, both options are se-

lected. The optically isolated output is available at connector

SK5. This isolated output is useful when the evaluation board

is connected directly to a high voltage (e.g., 220 V residential). A

typical connection diagram for this isolated output is shown in

Figure 5.

VPLUS

VMINUS

CFOUT

SK5B

SK5C

SK5A

U4

H11L1

JP14

A

B

R12

R4

R5

5V to 12V

COUNTER

+

R11

Figure 5. Typical Connection for Opto Output

All logic outputs can be monitored via test points 6 to 8

(TP6 to TP8). These test points provide easy access for

scope probes and meter probes.

OUTPUT FREQUENCY SELECTION

ADE7757 provides up to four different output frequencies

on F1 and F2. The output frequency selection is made via

the logic inputs S0 and S1—see ADE7757 datasheet. On

the evaluation board these inputs are set by using jumpers

JP12 and JP13. The logic input SCF is set via jumper 11

(JP11). For a full explanation of the ADE7757 output

frequency selection see the datasheet.

INTERNAL CLOCK

The ADE7757’s integrated oscillator serves as the clock

source to the chip. A precise 6.2 k

tolerance and low drift is used to drive the internal oscilla-

tor.

AGND VDD

SK3B

SK3A

SK5B

SK5C

SK5A

LOAD

V1P

V1N

JP1 = OPEN

JP2 = OPEN

JP3 = OPEN

JP4 = OPEN

JP5 = OPEN

JP6 = OPEN

JP7 = OPEN

JP8 = CLOSED

JP9 = N

JP11 = 1

JP12 = 1

JP13 = 0

JP14 = A,B

JP16 = P

JP17 = A

JP18 = CLOSED

R21 = REMOVED

2mV

100

imp/kWhr

JP5

JP6

R19

C18

R20

SK2A

SK1A

SK1B

SHUNT

5.000V

0.9776 Hz

5A

SK2B

NEUTRAL PHASE

V2

220V

5.000V

R15

R22

JP18

A

B

JP17

R21

FREQUENCY DISPLAY

AGND

SK1C

TP4

54.5mV

Figure 6. ADE7757 Evaluation Board as an Energy Meter

EVALUATION BOARD SET UP AS AN ENERGY

METER

Figure 6 shows a wiring diagram that allows a simple

energy meter to be implemented using the ADE7757

evaluation board. The current transducer used in this ex-

ample is a 400 µ

with a line voltage of 220 V and a maximum current of

25 A. The frequency outputs F1 and F2 can be used to

drive a mechanical counter. These outputs will be cali-

brated to provide 100 imp/kWhr. The logic output CF

has an output frequency that can be up to 2048 times higher