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Data Sheet

ADE9103/ADE9112/ADE9113

APPLICATIONS INFORMATION

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Rev. A | 29 of 55

POLYPHASE ENERGY METERS

The ADE9103/ADE9112/ADE9113 are designed for use in 3-phase

energy metering systems in which two, three, or four ADE9103/

ADE9112/ADE9113 devices are managed by a main device con-

taining a SPI, usually a microcontroller. The integrated signal and

power isolation of the ADE9112 and ADE9113 is required for phase

current and voltage sensing often referred to as high-side sensing.

Isolation provides both a safety barrier against high voltages for

personnel and enables SPI communication across the high voltage

offset between the ADC connected to each phase and a shared mi-

crocontroller. The ADE9103 can be used for neutral measurements

where safety isolation is not required.

Figure 35. Phase A Current and Voltage Sensing

Figure 35 shows Phase A of a 3-phase energy meter. The Phase

A current, IA, is sensed with a shunt. A terminal of the shunt

is connected to the IM pin of the ADE9112 and ADE9113 and

becomes the ground reference of the isolated side of the ADE9112

and ADE9113. Phase A to the neutral voltage, VAN, is sensed with

a resistor divider. The V1M, IM, and AGND pins are connected

as a single node. Note that the voltages measured by the ADCs

of the ADE9112 and ADE9113 are opposite to VAN and IA, a

classic approach in single-phase metering. The other ADE9112

and ADE9113 devices that monitor Phase B and Phase C are

connected in a similar way.

The V2 voltage channel (V2P and V2M pins) is intended for a

secondary voltage measurement, and it is available only on the

ADE9103 and ADE9113. In Figure 35, the V2 voltage channel is

used to measure the voltage across a relay to verify the state of

the relay. If the V2 voltage channel is not used on the ADE9103

and ADE9113 devices, connect the V2P pin to the V2M pin. For the

ADE9112, Pin 7 and Pin 8 are no connect, and these pins must be

left floating or tied together.

Figure 36. Neutral Line and Neutral to Earth Voltage Monitoring

Figure 36 shows how the ADE9103/ADE9112/ADE9113 inputs are

connected when the neutral line of a 3-phase system is monitored.

The neutral current is sensed using a shunt and the voltage across

the shunt is measured at the fully differential inputs, IP and IM.

The earth to neutral voltage is sensed with a voltage divider at the

single-ended inputs, V1P and V1M.

Figure 37 shows a block diagram of a 3-phase energy meter that

uses four ADE9103/ADE9112/ADE9113 devices and a microcon-

troller. One 16.384 MHz crystal provides the clock to the ADE9112

and ADE9113 that senses the Phase A current and voltage. The

ADE9103/ADE9112/ADE9113 devices that sense the Phase B,

Phase C, and neutral currents and voltages are clocked by a signal

generated at the CLKOUT/ DREADY pin of the ADE9112 and

ADE9113 that is placed to sense the Phase A current and voltage.

As an alternative configuration, the microcontroller can generate a

16.384 MHz clock to all ADE9103/ADE9112/ADE9113 devices at

the XTALIN pin. Note that the XTALIN pin can receive a clock with a

frequency within the 15.84 MHz to 16.547 MHz range, as specified

in Table 2.

Figure 37. 3-Phase Energy Meter Using Four Devices

The microcontroller uses the SPI port to communicate with the

ADE9103/ADE9112/ADE9113 devices. Four of the input and output

pins, CS_A, CS_B, CS_C, and CS_N, generate the SPI CS sig-

nals. The SCLK, MOSI, and MISO pins of the microcontroller are

directly connected to the corresponding SCLK, MOSI, and MISO

pins of each ADE9103/ADE9112/ADE9113 device corresponding

to the SPI configuration (see Figure 38 and Figure 39 ). In the

case of the SPI daisy-chain configuration, the CS signals from all

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