ADE7753ARSZ Analog Devices Inc, ADE7753ARSZ Datasheet - Page 17

• Manufacturer Part Number: ADE7753ARSZ
• Description: IC ENERGY METERING 1PHASE 20SSOP
• Manufacturer: Analog Devices Inc

Specifications of ADE7753ARSZ

• 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
• Ic Function: Single-Phase Multifunction Metering IC
• Supply Voltage Range: 4.75V To 5.25V
• Operating Temperature Range: -40°C To +85°C
• Digital Ic Case Style: SSOP
• No. Of Pins: 20
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: EVAL-ADE7753ZEB - BOARD EVALUATION AD7753
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

–89.70
–89.75
–89.80
–89.85
–89.90
–89.95
–90.00
–90.05
–1.0
–1.5
–2.0
–2.5
–3.0
–3.5
–4.0
–4.5
–5.0
–5.5
–6.0
–88.0
–88.5
–89.0
–89.5
–90.0
–90.5
Digital Integrator and Phase Compensator (40 Hz to 70 Hz)
Digital Integrator and Phase Compensator (40 Hz to 70 Hz)
40
40
Figure 37. Combined Phase Response of the
Figure 39. Combined Phase Response of the
Digital Integrator and Phase Compensator
Figure 38. Combined Gain Response of the
45
45
10
50
2
50
FREQUENCY (Hz)
FREQUENCY (Hz)
FREQ
FREQUENCY (Hz)
55
55
60
60
10
3
65
65
02875-0-038
02875-0-037
02875-0-039
70
70
Rev. A | Page 17 of 60
Note that the integrator has a –20 dB/dec attenuation and an
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. The di/dt sensor
has a 20 dB/dec gain associated with it. It also generates signifi-
cant high frequency noise, therefore a more effective anti-
aliasing filter is needed to avoid noise due to aliasing—see the
Antialias Filter section.
When the digital integrator is switched off, the ADE7753 can be
used directly with a conventional current sensor such as a current
transformer (CT) or with a low resistance current shunt.
ZERO-CROSSING DETECTION
The ADE7753 has a zero-crossing detection circuit on
Channel 2. This zero crossing is used to produce an external
zero-crossing signal (ZX), and it is also used in the calibration
mode—see the Calibrating an Energy Meter Based on the
ADE7753 section. The zero-crossing signal is also used to
initiate a temperature measurement on the ADE7753—see the
Temperature Measurement section.
Figure 40 shows how the zero-crossing signal is generated from
the output of LPF1.
The ZX signal goes logic high on a positive-going zero crossing
and logic low on a negative-going zero crossing on Channel 2.
The zero-crossing signal ZX is generated from the output of
LPF1. LPF1 has a single pole at 140 Hz (at CLKIN = 3.579545
MHz). As a result, there is a phase lag between the analog input
signal V2 and the output of LPF1. The phase response of this
filter is shown in the Channel 2 Sampling section. The phase lag
response of LPF1 results in a time delay of approximately
1.14 ms (@ 60 Hz) between the zero crossing on the analog
inputs of Channel 2 and the rising or falling edge of ZX.
V 2
V2P
V2N
0.93
1.0
PGA2
×
×
Figure 40. Zero-Crossing Detection on Channel 2
1,
8,
V2
{GAIN [7:5]}
×
×
2,
16
×
2.32° @ 60Hz
1,
REFERENCE
LPF1
f
ADC 2
–
3dB
LPF1
= 140Hz
ZX
1
–63% TO +63% FS
CROSS
ZERO
ADE7753
TO
MULTIPLIER
ZX
02875-0-040