ade7518 Analog Devices, Inc., ade7518 Datasheet - Page 62

• Manufacturer Part Number: ade7518
• Description: Single-phase Energy Measurement Ic With 8052 Mcu, Rtc, And Lcd Driver
• Manufacturer: Analog Devices, Inc.

ADE7518
ENERGY REGISTER SCALING
The ADE7518 provides measurements of active, reactive, and
apparent energies that use separate paths and filtering for calcula-
tion. The difference in data paths may result in small differences
in LSB weight between active, reactive, and apparent energy
registers. These measurements are internally compensated so that
the scaling is nearly one to one. The relationship between these
registers is shown in Table 44.
Table 44. Energy Registers Scaling
Line Frequency = 50 Hz
VAR = 0.9952 × WATT
VA = 0.9978 × WATT
VAR = 0.9997 × WATT
VA = 0.9977 × WATT
Line Frequency = 60 Hz
VAR = 0.9949 × WATT
VA = 1.0015 × WATT
VAR = 0.9999 × WATT
VA = 1.0015 × WATT
Integrator
Off
Off
On
On
Rev. 0 | Page 62 of 128
ENERGY MEASUREMENT INTERRUPTS
The energy measurement part of the ADE7518 has its own
interrupt vector for the 8052 core, Vector Address 0x004B (see
the Interrupt Vectors section). The bits set in the Interrupt
Enable 1 SFR (MIRQENL, 0xD9), Interrupt Enable 2 SFR
(MIRQENM, 0xDA), and Interrupt Enable 3 SFR (MIRQENH,
0xDB) enable the energy measurement interrupts that are
allowed to interrupt the 8052 core. If an event is not enabled,
it cannot create a system interrupt.
The ADE interrupt stays active until the status bit that has created
the interrupt is cleared. The status bit is cleared when a zero is
written to this register bit.