Datasheet

ADE7116/ADE7156/ADE7166/ADE7169/ADE7566/ADE7569
Rev. B | Page 56 of 152
FREQUENCY (Hz)
–1.0
–6.0
40 7045
GAIN (dB)
50 55 60 65
–1.5
–2.0
–2.5
–3.5
–4.5
–5.5
–3.0
–4.0
–5.0
06353-029
The ADE7169/ADE7569 have a built-in digital integrator to
recover the current signal from the di/dt sensor. The digital
integrator on the current channel is switched off by default when
the ADE7169/ADE7569 are powered up. Setting the INTE bit
(Bit 5) in the MODE1 register (Address 0x0B) turns on the
integrator. Figure 51 to Figure 54 show the gain and phase
response of the digital integrator.
FREQUENCY (Hz)
10
GAIN (dB)
0
–10
–20
–30
–40
–50
100 1000
06353-027
Figure 53. Combined Gain Response of the Digital Integrator and
Phase Compensator (40 Hz to 70 Hz)
–89.75
–89.80
–89.85
–89.90
–89.95
–90.00
FREQUENCY (Hz)
PHASE (Degrees)
40 45 7050 55 60 65
–90.05
–89.70
06353-030
Figure 51. Combined Gain Response of the Digital Integrator and
Phase Compensator
FREQUENCY (Hz)
10
2
10
3
06353-106
FREQ
–88.0
PHASE (Degrees)
–88.5
–89.0
–89.5
–90.0
–90.5
Figure 54. Combined Phase Response of the Digital Integrator and
Phase Compensator (40 Hz to 70 Hz)
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
significant high frequency noise. Therefore, a more effective
antialiasing filter is needed to avoid noise due to aliasing (see
the Antialiasing Filter section).
Figure 52. Combined Phase Response of the Digital Integrator and
Phase Compensator
When the digital integrator is switched off, the ADE7169/ADE7569
can be used directly with a conventional current sensor, such as a
current transformer (CT), or with a low resistance current
shunt.