WM8351 datasheet(175/330 Pages) WOLFSON

No. de pieza	WM8351

Descripción Electrónicos	Wolfson AudioPlus??Stereo CODEC with Power Management

PDF	330 Pages

Scroll/Zoom	100%

Fabricante Electrónico	WOLFSON [Wolfson Microelectronics plc]

Página de inicio	http://www.wolfsonmicro.com

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175 / 330 page

Production Data

WM8351

PD, April 2012, Rev 4.5

175

19.5 CALIBRATION

The on-chip reference VREF provides a highly accurate reference voltage to the AUXADC. For best

measurement accuracy, the WM8351 provides a way to determine the voltage offset of the

AUXADC’s VREF buffer and the gain error introduced by scaling the AUXADC input. Measured data

can then be adjusted accordingly, eliminating these errors.

To determine the buffer’s offset, the AUXADC AUX3 input is disconnected from the AUX3 pin and

connected to the unbuffered VREF voltage. Note that input scaling must be used, (i.e.

AUXADC_SCALE3 = 10 or 11), in order to ensure that the AUXADC input is within the measurable

range. Measuring this voltage using the buffered VREF as the reference (AUXADC_REF3 = 1) makes

it possible to calculate the combined error.

ADDRESS

BIT

LABEL

DEFAULT

DESCRIPTION

R145 (91h)

Digitizer Control

(2)

AUXADC_CAL

Configure AUX3 input to be the

VREF supply for AUXADC

calibration.

0 = AUX3 input connected to

AUX3 pin

1 = AUX3 input connected to

unbuffered VREF

Table 118 AUXADC Calibration

WM8351 Datasheet(PDF) 175 Page - Wolfson Microelectronics plc