EVAL-ADE7751ZEB Analog Devices Inc, EVAL-ADE7751ZEB Datasheet - Page 16

• Manufacturer Part Number: EVAL-ADE7751ZEB
• Description: BOARD EVALUATION FOR ADE7751
• Manufacturer: Analog Devices Inc

Specifications of EVAL-ADE7751ZEB

• Main Purpose: Power Management, Energy/Power Meter
• Utilized Ic / Part: ADE7751
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Secondary Attributes: -
• Embedded: -
• Primary Attributes: -

ADE7751
When selecting a suitable F
frequency output at I
of 100 imp/kWhr should be compared with Column 4 of Table VI.
The frequency that is closest in Table VI will determine the best
choice of frequency (F
mum current of 25 A is being designed, the output frequency on F1
and F2, with a meter constant of 100 imp/kWhr, is 0.153 Hz at 25 A
and 220 V (from Table V). Looking at Table VI, the closest
frequency to 0.153 Hz in column four is 0.17 Hz. Therefore F
(3.4 Hz—see Table II) is selected for this design.
Frequency Outputs
Figure 1 shows a timing diagram for the various frequency
outputs. The outputs F1 and F2 are the low-frequency outputs
that can be used to directly drive a stepper motor or electrome-
chanical impulse counter. The F1 and F2 outputs provide two
alternating low-going pulses. The pulsewidth (t
and the time between the falling edges of F1 and F2 (t
approximately half the period of F1 (t
If, however, the period of F1 and F2 falls below 550 ms (1.81 Hz),
the pulsewidth of F1 and F2 is set to half of their period. The maxi-
mum output frequencies for F1 and F2 are shown in Table III.
0.200 (5.05)
0.125 (3.18)
(5.33)
0.210
MAX
PIN 1
0.022 (0.558)
0.014 (0.356)
24
1
1.275 (32.30)
1.125 (28.60)
MAX
0.100
(2.54)
BSC
1–4
24-Lead Plastic DIP
(maximum load) with a meter constant
). For example, if a meter with a maxi-
1–4
0.070 (1.77)
0.045 (1.15)
frequency for a meter design, the
(N-24)
13
12
0.280 (7.11)
0.240 (6.10)
0.060 (1.52)
0.015 (0.38)
SEATING
PLANE
2
).
0.150
(3.81)
MIN
0.325 (8.25)
0.300 (7.62)
1
) is set at 275 ms
0.015 (0.381)
0.008 (0.204)
Dimensions shown in inches and (mm).
OUTLINE DIMENSIONS
0.195 (4.95)
0.115 (2.93)
3
) is
2
–16–
The high-frequency CF output is intended to be used for
communications and calibration purposes. CF produces a
90 ms wide active high pulse (t
tional to active power. The CF output frequencies are given in
Table IV. As in the case of F1 and F2, if the period of CF (t
falls below 180 ms, the CF pulsewidth is set to half the period.
For example, if the CF frequency is 20 Hz, the CF pulse-
width is 25 ms.
NO LOAD THRESHOLD
The ADE7751 also includes a “no load threshold” and “start-
up current” feature that will eliminate any creep effects in the
meter. The ADE7751 is designed to issue a minimum output
frequency. Any load generating a frequency lower than this
minimum frequency will not cause a pulse to be issued on F1,
F2, or CF. The minimum output frequency is given as 0.0014%
of the full-scale output frequency for each of the F
selections (see Table II). For example, for an energy meter with
a meter constant of 100 imp/kWhr on F1, F2 using F
the maximum output frequency at F1 or F2 would be 0.0014%
of 3.4 Hz or 4.76
CF (64 F1 Hz). In this example, the no load threshold would be
equivalent to 1.7 W of load or a start-up current of 8 mA at 220 V.
Compare this value to the IEC1036 specification, which states
that the meter must start up with a load equal to or less than
0.4% Ib. For a 5 A(Ib) meter, 0.4% of Ib is equivalent to 20 mA.
0.301 (7.64)
0.311 (7.9)
0.078 (1.98)
0.068 (1.73)
0.008 (0.203)
0.002 (0.050)
24
1
PIN 1
0.0256
(0.65)
BSC
24-Shrink Small Outline Package
0.328 (8.33)
0.318 (8.08)
0.015 (0.38)
0.010 (0.25)
10
–5
Hz. This would be 3.05
(RS-24)
SEATING
0.066 (1.67)
PLANE
13
12
0.07 (1.78)
4
0.205 (5.207)
) at a frequency that is propor-
0.212 (5.38)
0.009 (0.229)
0.005 (0.127)
8°
0°
1–4
2
10
frequency
(3.4 Hz),
–3
0.022 (0.559)
0.037 (0.94)
REV. 0
Hz at
5
)