Datasheet

AD7707
Rev. B | Page 32 of 52
POWER-UP AND CALIBRATION
On power-up, the AD7707 performs an internal reset that sets
the contents of the internal registers to a known state. There are
default values loaded to all registers after power-on or reset. The
default values contain nominal calibration coefficients for the
calibration registers. However, to ensure correct calibration for
the device, a calibration routine should be performed after
power-up. A calibration should be performed if the update rate
or gain are changed.
The power dissipation and temperature drift of the AD7707 are
low and no warm-up time is required before the initial calibration
is performed. However, if an external reference is being used,
this reference must stabilize before calibration is initiated.
S
imilarly, if the clock source for the part is generated from a
crystal or resonator across the MCLK pins, the start-up time for
the oscillator circuit should elapse before a calibration is
initiated on the part (see the Clocking and Oscillator Circuit
section).