Data Sheet

ADE7912/ADE7913

Rev. 0 | Page 33 of 44

POWER-UP AND INITIALIZATION PROCEDURES

At power-up or after a hardware or software reset, the following

steps must be executed for a microcontroller managing a system

formed by one or multiple ADE7912/ADE7913 devices.

Power-Up Procedure for Systems with a Single

ADE7912/ADE7913

For one standalone ADE7912/ADE7913 device managed by a

microcontroller, the power-up procedure is as follows (see

Figure 52):

1. Connect a crystal between the XTAL1 and XTAL2 pins.

that the ADE7912/ADE7913 device starts functioning

correctly, the supply must reach 3.3 V − 10% in less than

23 ms from approximately a 2.6 V level. The ADE7912/

ADE7913 device starts to function.

3. The dc-to-dc converter powers up and supplies the isolated

side of the ADE7912/ADE7913. The Σ-Δ modulators

become functional. This process takes approximately

100 ms to execute when the recommended capacitors on

used. After this time, the isolated side of the

ADE7912/ADE7913 is fully functional.

4. To determine when the ADE7912/ADE7913 device is

ready to accept commands, read the STATUS0 register

until Bit 0 (RESET_ON) is cleared to 0. This happens

approximately 20 ms after the ADE7912/ADE7913 start to

function and indicates that the nonisolated side of the

ADE7912/ADE7913 is fully functional using the default

settings.

5. Initialize the CONFIG register and the EMI_CTRL

emissions control register.

6. Protect the user accessible and internal configuration

registers by setting the lock register to 0xCA. See the

Protecting the Integrity of Configuration Registers section.

7. When the ADC conversion data is available, the

ADE7912/ADE7913 device begins generating a signal that

is active low at the CLKOUT/DREADY pin for 64 CLKIN

cycles (15.625 µs for CLKIN = 4.096 MHz).

DREADY functionality is enabled by default at the

CLKOUT/DREADY pin.

8. The microcontroller reads the IWV, V1WV, V2WV,

ADC_CRC, and STATUS0 registers in SPI burst mode (see

the SPI Read Operation in Burst Mode section for more

information).

Note that this power-up procedure also applies in the same way

to systems that have multiple ADE7912/ADE7913 devices, each

clocked from its own crystal. Every ADE7912/ADE7913 device

is powered up and started independently.

Figure 52. Power-Up Procedure for Systems with One or Multiple ADE7912/ADE7913 Devices, Each Clocked from Its Own Crystal

ADE7912/ADE7913

POWERED UP

3.3V – 10%

≈2.6V

ADE7912/ADE7913

START

FUNCTIONING

BIT STATUS0[0]

(RESET_ON)

CLEARED TO 0

DC-TO-DC CONVERTER

POWERED UP AND

Σ-Δ MODULATORS

FUNCTIONAL

0V

POR TIMER

TURNED ON

ADE7912/ADE7913

NONISOLATED

SIDE READY

ADE7912/ADE7913

ISOLATED

SIDE READY

23ms

100ms

20ms