CS5467 datasheet(23/46 Pages) CIRRUS

23 / 46 page

CS5467

DS714F3

7. USING THE CS5467

7.1 Initialization

The CS5467 uses a power-on-reset circuit (POR) to

provide an internal reset until the analog voltage reach-

es 4.0 V. The RESET input pin can also be used by the

application circuit to reset the part.

After RESET is removed and the oscillator is stable, an

initialization program is executed to set the default reg-

ister values.

A Software Reset command is also provided to allow

the application to run the initialization program without

removing power or asserting RESET.

The application should avoid sending commands during

initialization. The DRDY bit in the Status register indi-

cates when the initialization program has completed.

7.2 Power-down States

The CS5467 has two power-down states, stand-by and

sleep. In the stand-by state, all circuitry except the volt-

age reference and crystal oscillator is powered off. In

sleep state, all circuitry except the instruction decoder is

powered off.

To return the device to the active state, send a Wake-

up/Halt command to the device. When returning from

stand-by mode, registers will retain their contents prior

to entering the stand-by state. When returning from

sleep mode, a complete initialization occurs.

7.3 Voltage Tamper Correction

The CSS5467 provides compensation for meter tam-

pering on voltage channels.

If the application detects that the voltage input has been

impaired it may choose to use the fixed internal RMS

voltage reference by setting the VFIX bit in the Modes

fault 0.707107 (full-scale RMS) but can be changed by

the application program. (See figure 9)

Figure 9. Fixed RMS Voltage Selection

CS5467 Datasheet(PDF) 23 Page - Cirrus Logic