P19/29

Rev. M, May 2010

ML5012

5. A/D conversion mode

The A/D conversion mode converts the analog voltage on the A/D pin into the digital value. The input analog voltage

is successively compared with weighted voltages from the capacitor array. Digitized conversion data (12-bit) are

stored into 12 bits A/D register A/D[11:0].

The time required for the converter to complete conversion is as follows:

Conversion duration = Oscillator clock period x 15

Example:

(a). 150us (oscillator clock at 100KHz)

(b). 75us (oscillator clock at 200kHz)

Caution:

While in the A/D conversion mode, do not use A/D register A/D[11:0] to store other data.

5-1. Selecting PGA input channel AB & B, PGA Gain & A/D enable control

Executing STCH command to enable Oscillator and then select one of PGA input channel AB (ie. CHA1~4

or CHB1~4) & input channel B (ie. CHB1~4 or AGND) for differential or single end analog input.

Setting of Oscillator enable pins

Before using A/D conversion, ENOSC bit must be set to 1 to start-up the oscillator in order to

provide the clock for A/D conversion mode.

It is recommended to turn off the oscillator when A/D conversion mode is completed in order to

reduce the power consumption.

Setting of AD Output Range

Setting of AD Output Range

Output Range

AD_Range = 0

0 ~ 4,095

AD_Range = 1

-2,047 ~ 2,047

Please refer to Section 3-4 for more details.