ADE7759ARSRL Analog Devices Inc, ADE7759ARSRL Datasheet - Page 13

• Manufacturer Part Number: ADE7759ARSRL
• Description: IC ENERGY METERING 1PHASE 20SSOP
• Manufacturer: Analog Devices Inc

Specifications of ADE7759ARSRL

• Rohs Status: RoHS non-compliant
• Input Impedance: 390 KOhm
• Measurement Error: 0.1%
• Voltage - I/o High: 2.4V
• Voltage - I/o Low: 0.8V
• Current - Supply: 3mA
• Voltage - Supply: 4.75 V ~ 5.25 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 20-SSOP (0.200", 5.30mm Width)
• Meter Type: Single Phase
• For Use With: EVAL-ADE7759EBZ - BOARD EVALUATION FOR ADE7759

REV. A
Figure 11. Phase Response of the Digital Integrator
Figure 12. Gain Response of the Digital Integrator
(40 Hz to 70 Hz)
Figure 10. Gain Response of the Digital Integrator
–88.0
–88.5
–89.0
–89.5
–90.0
–90.5
–91.0
–91.5
–92.0
–10
–20
–30
–40
–50
–60
30
20
10
–1
–2
–3
–4
–5
–6
10
0
10
0
40
1
1
45
10
10
50
2
2
FREQUENCY – Hz
FREQUENCY – Hz
FREQUENCY – Hz
55
10
10
60
3
3
65
10
10
70
4
4
–13–
Note that the integrator has a –20 dB/dec attenuation and
approximately –90° phase shift. When combined with a di/dt
sensor, the resulting magnitude and phase response should be a
flat gain over the frequency band of interest. However, the di/dt
sensor has a 20 dB/dec gain associated with it, and generates
significant high frequency noise. A more effective antialiasing
filter is needed to avoid noise due to aliasing—see Antialias
Filter section.
When the digital integrator is switched off, the ADE7759 can be
used directly with a conventional current sensor such as current
transformer (CT) or a low resistance current shunt.
ZERO CROSSING DETECTION
The ADE7759 has a zero crossing detection circuit on Channel 2.
This zero crossing is used to produce an external zero cross
signal (ZX), and it is also used in the calibration mode—see
Energy Calibration section. The zero crossing signal is also used
to initiate a temperature measurement on the ADE7759—see
Temperature Measurement section. Figure 14 shows how the
zero cross signal is generated from the output of LPF1.
V2
Figure 13. Phase Response of the Digital Integrator
(40 Hz to 70 Hz)
V2N
V2P
Figure 14. Zero Cross Detection on Channel 2
–89.980
–89.985
–89.990
–89.995
–90.000
–90.005
–90.010
–90.015
–90.020
0.93
1.0
PGA2
40
1,
8,
V2
{GAIN [7:5]}
2,
16
4,
21.04 @ 60Hz
45
REFERENCE
LPF1
f
ADC 2
–3dB
50
LPF1
FREQUENCY – Hz
= 156Hz
ZX
1
55
–63% TO +63% FS
CROSS
ZERO
60
ADE7759
65
TO
MULTIPLIER
ZX
70