AD7148 Analog Devices, AD7148 Datasheet - Page 19

• Manufacturer Part Number: AD7148
• Manufacturer: Analog Devices

Specifications of AD7148

• Resolution (bits): 16bit
• # Chan: 8
• Sample Rate: 250kSPS
• Interface: I²C/Ser 2-Wire,Ser
• Analog Input Type: SE-Uni
• Ain Range: ± 8 pF (Delta C)
• Adc Architecture: Sigma-Delta
• Pkg Type: CSP

CDC CONVERSION SEQUENCE
PROXIMITY DETECTION
Figure 29. Low Power Mode Proximity Detection with Forced Recalibration Example with LP_PROXIMITY_CNT = 4 and LP_PROXIMITY_RECAL = 40
RECALIBRATION
CALIBRATION
(INTERNAL)
(INTERNAL)
(INTERNAL)
(INTERNAL)
NOTES
1. SEQUENCE CONVERSION TIME
2.
3.
4.
t
t
t
CALDIS
RECAL_TIMEOUT
RECAL
USER APPROACHES
SENSOR HERE
= 2 ×
=
t
CONV_LP
t
CONV_LP
=
t
CONV_FP
USER LEAVES SENSOR
× LP_PROXIMITY_CNT × 4
CALIBRATION DISABLED
AREA HERE
× LP_PROXIMITY_RECAL
t
CONV_LP
16
t
CALDIS
=
t
CONV_FP
Rev. A | Page 19 of 56
+ LP_CONV_DELAY
30
MEASURED CDC VALUE > STORED AMBIENT
RECALIBRATION TIME-OUT
BY PROXIMITY_RECAL _LVL
t
RECAL_TIMEOUT
t
RECAL
70
CALIBRATION ENABLED
AD7148
t
CONV_LP