STMPE821QTR STMicroelectronics, STMPE821QTR Datasheet - Page 31

• Manufacturer Part Number: STMPE821QTR
• Description: IC CTLR TOUCH KEY 8CH CAP 16-QFN
• Manufacturer: STMicroelectronics
• Type: Capacitiver

Specifications of STMPE821QTR

• Number Of Inputs/keys: 8 Key
• Data Interface: I²C
• Voltage - Supply: 1.65 V ~ 1.95 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 16-QFN
• Voltage Supply Source: Single Supply
• Resolution: 7 bit to 10 bit
• Interface Type: I2C
• Supply Voltage (max): 3.6 V
• Supply Voltage (min): 2.7 V
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• Number Of Channels: 8
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Sampling Rate (per Second): -
• Resolution (bits): -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 497-8826-2

STMPE821
FILTER_PERIOD
Address:
Type:
Reset:
Description:
FILTER_THRESHOLD
Address:
Type:
Reset:
Description:
REFERENCE_DELAY
Address:
Type:
Reset:
Description:
RESERVED
7
7
7
[7:0] FILTER_COUNT:
[7:0] FILTER_THRESHOLD:
[6:0] REFERENCE_DELAY:
[7] RESERVED
6
6
6
0x28
R/W
0x00
Filter period.
Additional filter to stabilize touch output in AFS mode.
AFS touch output is monitored for Filter Count [7:0] times every integration time. For each time
a "touch status" is detected, an internal "Filter Counter" is incremented once. This counter
value is then compared with Filter Threshold (register 0x3E)
0x29
R/W
0x00
Filter threshold.
An internal "Filter Counter" is compared with Filter Threshold [7:0] to determine if a valid touch
has occurred.
0x2A
R/W
0x00
Shifting of capacitive sensor dynamic range. The capacitance value set into this
register is in effect, equivalent to capacitor connected to the A_Ref pin.
Valid range = 0-127
Each step represents capacitance value of 0.05 pF
Warm reset is required after this value is updated
5
5
5
4
4
4
Doc ID 14478 Rev 5
FILTER_THRESHOLD
FILTER_COUNT
3
3
3
REFERENCE_DELAY
2
2
2
Capacitive touch module registers
1
1
1
Reference delay
Filter threshold
Filter period
0
0
0
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