ad7147a-1acbz-r Analog Devices, Inc., ad7147a-1acbz-r Datasheet - Page 19

• Manufacturer Part Number: ad7147a-1acbz-r
• Description: Captouch Programmable Controller For Single-electrode Capacitance Sensors
• Manufacturer: Analog Devices, Inc.

Table 13. Proximity Control Registers (See Figure 33)
Bit Name
FP_PROXIMITY_CNT
LP_PROXIMITY_CNT
FP_PROXIMITY_RECAL
LP_PROXIMITY_RECAL
PROXIMITY_RECAL_LVL
PROXIMITY_DETECTION_RATE
CDC CONVERSION
CDC CONVERSION
CALIBRATION
CALIBRATION
(INTERNAL)
DETECTION
(INTERNAL)
(INTERNAL)
DETECTION
SEQUENCE
(INTERNAL)
(INTERNAL)
(INTERNAL)
PROXIMITY
SEQUENCE
PROXIMITY
NOTES
1. SEQUENCE CONVERSION TIME
2. PROXIMITY IS SET WHEN THE USER APPROACHES THE SENSOR, AT WHICH TIME THE INTERNAL CALIBRATION IS DISABLED.
3.
t
CALDIS
USER APPROACHES
USER APPROACHES
Length
(Bits)
4
4
10
6
8
6
Figure 30. Example of Low Power Mode Proximity Detection (LP_PROXIMITY_CNT = 4)
Figure 29. Example of Full Power Mode Proximity Detection (FP_PROXIMITY_CNT = 1)
= (
SENSOR
SENSOR
t
CONV_LP
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
× LP_PROXIMITY_CNT × 4).
Register Address
0x002[7:4]
0x002[11:8]
0x004[9:0]
0x004[15:10]
0x003[7:0]
0x003[13:8]
SENSOR AREA
USER LEAVES
SENSOR AREA
USER LEAVES
t
CONV_LP
CALIBRATION DISABLED
CALIBRATION DISABLED
=
Rev. 0 | Page 19 of 68
t
CONV_FP
Description
Calibration disable time in full power mode.
Calibration disable time in low power mode.
Full power mode proximity recalibration time control.
Low power mode proximity recalibration time control.
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).
+ LP_CONV_DELAY.
t
CALDIS
t
CALDIS
17 18 19 20 21 22 23 24
17 18 19 20 21 22 23 24
CALIBRATION ENABLED
CALIBRATION ENABLED
t
t
CONV_LP
CONV_FP
AD7147A