AD7147ACPZ-REEL Analog Devices Inc, AD7147ACPZ-REEL Datasheet - Page 27

• Manufacturer Part Number: AD7147ACPZ-REEL
• Description: IC,Converter, Other/Special/Miscellaneous,LLCC,24PIN
• Manufacturer: Analog Devices Inc
• Series: CapTouch™r
• Type: Capacitive Sensor Controllerr

Specifications of AD7147ACPZ-REEL

• Resolution (bits): 16 b
• Data Interface: Serial, SPI™
• Voltage Supply Source: Single Supply
• Voltage - Supply: 2.6 V ~ 3.6 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 24-LFCSP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: EVAL-AD7147EBZ - BOARD EVAL FOR AD7147ACPZEVAL-AD7147-1EBZ - BOARD EVAL FOR AD7147ACPZ-1
• Sampling Rate (per Second): -
• Lead Free Status / Rohs Status: Compliant

Table 14. Additional Information About Environmental Calibration and Adaptive Threshold Registers
Register/Bit
NEG_THRESHOLD_SENSITIVITY
NEG_PEAK_DETECT
POS_THRESHOLD_SENSITIVITY
POS_PEAK_DETECT
STAGEx_OFFSET_LOW
STAGEx_OFFSET_HIGH
STAGEx_OFFSET_HIGH_CLAMP
STAGEx_OFFSET_LOW_CLAMP
STAGEx_SF_AMBIENT
STAGEx_HIGH_THRESHOLD
STAGEx_LOW_THRESHOLD
16-BIT
CDC
Σ-Δ
16
Register
Location
Bank 2
Bank 2
Bank 2
Bank 2
Bank 2
Bank 2
Bank 2
Bank 2
Bank 3
Bank 3
Bank 3
Figure 39. Tracking the Minimum and Maximum Average Sensor Values
Description
Used in Equation 2. This value is programmed once at startup.
Used by internal adaptive threshold logic only.
The NEG_PEAK_DETECT is set to a percentage of the difference between the ambient
CDC value and the minimum average CDC value. If the output of the CDC approaches the
NEG_PEAK_DETECT percentage of the minimum average, the minimum average value is updated.
Used in Equation 1. This value is programmed once at startup.
Used by internal adaptive threshold logic only.
The POS_PEAK_DETECT is set to a percentage of the difference between the ambient
CDC value and the maximum average CDC value. If the output of the CDC approaches the
POS_PEAK_DETECT percentage of the maximum average, the maximum average value is updated.
Used in Equation 2. An initial value (based on sensor characterization) is programmed into
this register at startup. The AD7147 on-chip calibration algorithm automatically updates this
register based on the amount of sensor drift due to changing ambient conditions. Set this
register to 80% of the STAGEx_OFFSET_LOW_CLAMP value.
Used in Equation 1. An initial value (based on sensor characterization) is programmed into
this register at startup. The AD7147 on-chip calibration algorithm automatically updates this
register based on the amount of sensor drift due to changing ambient conditions. Set this
register to 80% of the STAGEx_OFFSET_HIGH_CLAMP value.
Used by internal environmental calibration and adaptive threshold algorithms only.
An initial value (based on sensor characterization) is programmed into this register at startup.
The value in this register prevents a user from causing the output value of a sensor to exceed
the expected nominal value.
Set this register to the maximum expected sensor response or the maximum change in CDC
output code.
Used by internal environmental calibration and adaptive threshold algorithms only.
An initial value (based on sensor characterization) is programmed into this register at startup.
The value in this register prevents a user from causing the output value of a sensor to exceed
the expected nominal value.
Set this register to the minimum expected sensor response or the minimum change in CDC
output code.
Used in Equation 1 and Equation 2. This is the ambient sensor output when the sensor is not
touched, as calculated using the slow FIFO.
Equation 1 value.
Equation 2 value.
DETECTION
DETECTION
MAXIMUM
MINIMUM
LEVEL
LEVEL
LOGIC
LOGIC
Rev. B | Page 27 of 72
STAGEx_HIGH_THRESHOLD
STAGEx_LOW_THRESHOLD
STAGEx_MAX_WORD0
STAGEx_MAX_WORD1
STAGEx_MAX_WORD2
STAGEx_MAX_WORD3
STAGEx_MIN_WORD0
STAGEx_MIN_WORD1
STAGEx_MIN_WORD2
STAGEx_MIN_WORD3
STAGEx_MAX_TEMP
BANK 3 REGISTERS
BANK 3 REGISTERS
BANK 3 REGISTERS
BANK 3 REGISTERS
STAGEx_MIN_TEMP
BANK 3 REGISTERS
BANK 3 REGISTERS
STAGEx_MAX_AVG
STAGEx_MIN_AVG
BANK 3 REGISTERS
BANK 3 REGISTERS
AD7147