EVAL-AD7147EBZ(Rev0) View Datasheet(PDF) - Analog Devices

Part Name

Description

Manufacturer

EVAL-AD7147EBZ
(Rev.:Rev0)

CapTouch™ Programmable Controller for Single-Electrode Capacitance Sensors

Analog Devices 

AD7147

Table 12. Proximity Control Registers (See Figure 33)

Bit Name

Length

(Bits) Register Address

FP_PROXIMITY_CNT

4

0x002 [7:4]

LP_PROXIMITY_CNT

4

0x002 [11:8]

FP_PROXIMITY_RECAL

8

0x004 [9:0]

LP_PROXIMITY_RECAL

6

0x004 [15:10]

PROXIMITY_RECAL_LVL

8

0x003 [7:0]

PROXIMITY_DETECTION_RATE 6

0x003 [13:8]

Description

Calibration disable time in full power mode.

Calibration disable time in low power mode.

Full power mode proximity recalibration time.

Low power mode proximity recalibration time.

Proximity recalibration level. This value multiplied by 16 controls the

sensitivity of Comparator 2 (see Figure 33).

Proximity detection rate. This value multiplied by 16 controls the

sensitivity of Comparator 1 (see Figure 33).

CDC CONVERSION

SEQUENCE

(INTERNAL)

PROXIMITY

DETECTION

(INTERNAL)

USER APPROACHES

SENSOR

USER LEAVES

SENSOR AREA

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

tCALDIS

tCONV_FP

CALIBRATION

(INTERNAL)

CALIBRATION DISABLED

CALIBRATION ENABLED

Figure 29. Example of Full Power Mode Proximity Detection (FP_PROXIMITY_CNT = 1)

CDC CONVERSION

SEQUENCE

(INTERNAL)

PROXIMITY

DETECTION

(INTERNAL)

USER APPROACHES

SENSOR

USER LEAVES

SENSOR AREA

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

tCALDIS

tCONV_LP

CALIBRATION

(INTERNAL)

CALIBRATION DISABLED

CALIBRATION ENABLED

NOTES

1. SEQUENCE CONVERSION TIME tCONV_LP = tCONV_FP + LP_CONV_DELAY.

2. PROXIMITY IS SET WHEN USER APPROACHES THE SENSOR, AT WHICH TIME THE INTERNAL CALIBRATION IS DISABLED.

3. tCALDIS = (tCONV_LP × LP_PROXIMITY_CNT × 4).

Figure 30. Example of Low Power Mode Proximity Detection (LP_PROXIMITY_CNT = 4)

Rev. 0 | Page 19 of 68

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