ade7755 Analog Devices, Inc., ade7755 Datasheet
ade7755
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ade7755 Summary of contents
Page 1
... The ADE7755 will remain in a reset condition DD until the supply voltage on AV below 4 V, the ADE7755 will also be reset and no pulses will be issued on F1, F2, and CF. Internal phase matching circuitry ensures that the voltage and current channels are phase matched whether the HPF in Chan- nel off ...
Page 2
... ADE7755–SPECIFICATIONS Parameter 1, 2 ACCURACY 1 Measurement Error on Channel 1 Gain = 1 Gain = 2 Gain = 8 Gain = 16 1 Phase Error Between Channels V1 Phase Lead 37 (PF = 0.8 Capacitive) V1 Phase Lag 60 (PF = 0.5 Inductive Power Supply Rejection Output Frequency Variation (CF Power Supply Rejection Output Frequency Variation (CF) ANALOG INPUTS ...
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... ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on the human body and test equipment and can discharge without detection. Although the ADE7755 features proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high-energy electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance degradation or loss of functionality ...
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... ADE7755 Figure 1. Timing Diagram for Frequency Outputs PIN CONFIGURATION DC RESET –4– REV. 0 ...
Page 5
... V can also be sustained on these inputs without risk of permanent damage. RESET 9 Reset Pin for the ADE7755. A logic low on this pin will hold the ADCs and digital circuitry in a reset condition. Bringing this pin logic low will clear the ADE7755 internal registers. 10 REF This pin provides access to the on-chip voltage reference ...
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... DGND This provides the ground reference for the digital circuitry in the ADE7755, i.e., multiplier, filters, and digital-to-frequency converter. This pin should be tied to the digital ground plane of the PCB. The digital ground plane is the ground reference for all digital circuitry, e.g., counters (mechanical and digital), MCUs, and indicator LEDs ...
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... TPC 1. Error Reading (Gain = 1) TPC 2. Error Reading (Gain = 2) TPC 3. Error Reading (Gain = 8) REV. 0 Typical Performance Characteristics– TPC 4. Error Reading (Gain = 16) TPC 5. Error Reading (Gain = 1) TPC 6. Error Reading (Gain = 2) –7– ADE7755 ...
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... ADE7755 TPC 7. Error Reading (Gain = 8) TPC 8. Error Reading (Gain = 16) TPC 9. Error Reading over Temperature with an External Reference (Gain = 2) TPC 10. Error Reading over Temperature with an External Reference (Gain = 16) TPC 11. Error Reading over Frequency DC RESET TPC 12. Test Circuit for Performance Curves – ...
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... TPC 13. Channel 1 Offset Distribution (Gain = 1) TPC 14. Channel 1 Offset Distribution (Gain = 2) TPC 15. PSR with Internal Reference (Gain = 16) REV. 0 TPC 16. Channel 1 Offset Distribution (Gain = 8) TPC 17. Channel 1 Offset Distribution (Gain = 16) TPC 18. PSR with External Reference (Gain = 16) –9– ADE7755 ...
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... All signal processing is carried out in the digital domain for superior stability over temperature and time. Figure 2. Signal Processing Block Diagram The low-frequency output of the ADE7755 is generated by accumulating this real power information. This low frequency inherently means a long accumulation time between output pulses ...
Page 11
... Channel V2 (Voltage Channel ) The output of the line voltage transducer is connected to the ADE7755 at this analog input. Channel fully differential voltage input. The maximum peak differential signal on (4) Channel 2 is 660 mV. Figure 5 illustrates the maximum signal levels that can be connected to the ADE7755 Channel 2. ...
Page 12
... PT (potential transformer) to provide complete isolation from the power line. In the second option, the ADE7755 is biased around the neutral wire, and a resistor divider provides a voltage signal that is proportional to the line voltage. Adjusting the ratio of Ra, Rb, and VR is also a convenient way of carrying out a gain calibration on the meter ...
Page 13
... This accumulation of the signal will suppress or average out any non-dc components in the instantaneous real power signal. The average value of a sinusoidal signal is zero. Hence, the frequency generated by the ADE7755 is proportional to the average real power. Figure 12 shows the digital-to-frequency conversion for steady load conditions, i.e., constant voltage and current. ...
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... TRANSFER FUNCTION Frequency Outputs F1 and F2 The ADE7755 calculates the product of two voltage signals (on Channel 1 and Channel 2) and then low-pass filters this product to extract real power information. This real power information is then converted to a frequency. The frequency information is output on F1 and F2 in the form of active low pulses ...
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... Table VI shows the output frequency on F1 and F2 when both 1–4 analog inputs are half scale. The frequencies listed in Table VI align very well with those listed in Table V for maximum load. –15– ADE7755 S0 F (Hz) CF Max for AC Signals (Hz) 1– ...
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... The ADE7755 also includes a “no load threshold” and “start- up current” feature that will eliminate any creep effects in the meter. The ADE7755 is designed to issue a minimum output frequency on all modes except when SCF = 0 and The no-load detection threshold is disabled on this output mode to accommodate specialized application of the ADE7755 ...