AD6650SLASHPCB datasheet(44/45 Pages) AD

44 / 45 page

AD6650

Rev. A | Page 43 of 44

0x22: Autocalibration Register [3:0]

Address 0x22 is the autocalibration register and controls the

automatic coarse dc autocalibration at start-up.

Bit 3

Reserved. This bit should be set to 0.

Bit 2

Reserved. This bit should be set to 1.

Bit 1

Determines whether to power down the VGA and mixer on a

coarse calibration. This should be set to 0 to allow the state

machine to power down the VGA and mixer. If it is known that

there is no dc input into the part, this can be set to 1 to improve

the correction performance, which allows more flexibility in

setting the lower threshold.

Bit 0

Enables the autocalibration. This should be set to 1 for

the calibration to run automatically. Then the AD6650 waits

approximately 20.63 ms after a Soft_SYNC or Pin_SYNC

enables the part and then runs a coarse dc calibration. This

allows some warm-up time for the analog path to thermally

stabilize.

0x23 to 0x3F: Reserved

These registers must not be written.

0x40 to 0x6F: Coefficient Memory

This memory is utilized to store up to forty-eight 20-bit RCF

coefficients shared by Channel A and Channel B.

0x70 to 0xFF: Reserved

These registers must not be written.

AD6650/PCB Datasheet(PDF) 44 Page - Analog Devices