[AK4160]

MS1313-E-01

2011/11

- 10 -

The voltage of a sense terminal is measured for N consecutive times. Then the first filter calculates the average value,

discarding the minimum and the maximum values. The N of the measurement time is user-selectable from 4, 6, 10, and

18 times. (Address 0x70 NF1S1-0 bits) The sampling rate is dependent on the charge time.

The second filter has the same structure as the first filter. The outputs of the first filter are input to the second filter. The N

of the measurement time is user-selectable from 4, 6, 10, and 18 times independent of the first filter. (Address 0x70

NF2S1-0 bits) The sampling rate of the second filter is user-selectable from 4ms to 512ms in factorial of 2 steps. (Address

0x74 TSR2-0 bits)

The output rate of the second filter is “Sampling Rate × Sample Count”. The output data is compared to “The Noncontact

Reference Value” that output by the calibration circuit for environment changes.

CS0

Sampling Rate

Result Update

Calculation of median averaging after 6 measurement,

repeating charge and discharge.

(6 Sample Setting in the first filter)

The Voltage of

Sense terminal

CS1

Calculation of median averaging after 4 times acquisition

of the output data from the first filter, and updating to

result

(4 Sample Setting in the second filter)

CS0

Data

CS1

Data

Figure 7. The Measurement of a Sense Terminal and The Data Update