Features: On-chip oscillator as clock source
High accuracy, supports 50 Hz/60 Hz IEC62053-21
Less than 0.1% error over a dynamic range of 500 to 1
Supplies positive-only average real power on frequency outputs F1 and F2
High frequency output CF calibrates and supplies instantaneous, positive-only real power
Logic output REVP indicates potential miswiring or negative power
Direct drive for electromechanical counters and 2-phase stepper motors (F1 and F2)
Proprietary ADCs and DSPs provide high accuracy over large variations in environmental conditions and time
On-chip power supply monitoring
On-chip creep protection (no-load threshold)
On-chip reference 2.45 V (20 ppm/°C typical) with external overdrive capability
Single 5 V supply, low power (20 mW typical)
Low cost CMOS processPinout
Specifications
| Parameter |
Rating |
VDD to AGND
VDD to DGND
Analog Input Voltage to AGND,
V1P, V1N, V2P, and V2N
Reference Input Voltage to AGND
Digital Input Voltage to DGND
Digital Output Voltage to DGND
Operating Temperature Range
Storage Temperature Range
Junction Temperature
16-Lead Plastic SOIC, Power Dissipation
JA Thermal Impedance1
Package Temperature Soldering |
−0.3 V to +7 V
−0.3 V to +7 V
−6 V to +6 V
−0.3 V to VDD + 0.3 V
−0.3 V to VDD + 0.3 V
−0.3 V to VDD + 0.3 V
−40°C to +85°C
−65°C to +150°C
150°C
350 mW
124.9°C/W
See J-STD-20 |
| Meter Type |
Single Phase |
| Package |
16-Lead SOIC |
| Active Energy Accuracy |
0.1% over 500:1 @25°C |
| Active Energy Bandwidth |
14kHz |
| Analog input range |
+/-32mV to +/- 500mV peak |
| Power Consumption |
20mW Typical |
| Reference Tempco |
20ppm/°C Typical |
DescriptionThe ADE77681 is a high accuracy, electrical energy metering IC. It is a pin reduction version of the ADE7755, enhanced with a precise oscillator circuit that serves as a clock source to the chip. It eliminates the cost of an external crystal or resonator, thus reducing the overall cost of a meter built with this IC. The chip directly interfaces with the shunt resistor.
The ADE7768 specifications surpass the accuracy require-ments of the IEC62053-21 standard. The AN-679 Application Note can be used as a basis for a description of an IEC61036 (equivalent to IEC62053-21) low cost, watt-hour meter reference design.
The only analog circuitry used in the ADE7768 is in the - ADCs and reference circuit. All other signal processing, such as multiplication and filtering, is carried out in the digital domain. This approach provides superior stability and accuracy over time and extreme environmental conditions.
The ADE7768 supplies positive-only average real power information on the low frequency outputs, F1 and F2. These outputs can be used to directly drive an electromechanical counter or interface with an MCU. The high frequency CF logic output, ideal for calibration purposes, provides instantaneous positive-only, real power information.
The ADE7768 includes a power supply monitoring circuit on the VDD supply pin. It remains inactive until the supply voltage on VDD reaches approximately 4 V. If the supply falls below 4 V, the ADE7768 also remains inactive and the F1, F2, and CF outputs are in their nonactive modes.
Internal phase matching circuitry ensures that the voltage and current channels are phase matched, while the HPF in the current channel eliminates dc offsets. An internal no-load threshold ensures that the ADE7768 does not exhibit creep when no load is present. When REVP is logic high, it does not generate any pulse on F1, F2, and CF.
The ADE7768 comes in a 16-lead, narrow body SOIC package.
ADE7768 Data Sheet
