STMPE16M31PXQTR STMicroelectronics, STMPE16M31PXQTR Datasheet - Page 48

• Manufacturer Part Number: STMPE16M31PXQTR
• Description: IC CTLR TOUCHKEY 16CHAN 32-QFN
• Manufacturer: STMicroelectronics
• Series: S-Touch™r
• Type: Capacitive, PWM, Ratio Enginer

Specifications of STMPE16M31PXQTR

• Featured Product: STMPE16M31PX
• Number Of Inputs/keys: 16 Key, Slider
• Data Interface: I²C
• Data Rate/sampling Rate (sps, Bps): 100k, 400k
• Voltage Reference: External
• Voltage - Supply: 2.7 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 32-VFQFN Exposed Pad
• Supply Voltage: 1.65 V to 1.95 V
• Number Of Channels: 16
• Dimensions: 4 mm L x 4 mm W x 0.8 mm H
• Temperature Range: - 40 C to + 85 C
• Termination Style: SMD/SMT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Current - Supply: -
• Resolution (bits): -
• Touch Panel Interface: -
• Other names: 497-10738-2

Touch sensor controller
13.1
48/75
Figure 12. Touch sensing module flowchart
Sampling rate calculation
The capacitive sensor operates with a 2 MHz base clock, a single capacitive sensor scans
up to 16 active channels.
The SCLK_DIV divides the sensor clock by 32-1024, giving 2 kHz-67.5 kHz sensor clock.
For capacitive sensing, a PRBS sequence is utilized to remove the effect of surrounding
noise. This PRBS has an average value of 4.5.
The effective total sampling rate is thus 2 kHz-67.5 kHz divided by 4.5, giving 440 Hz –
14 kHz.
If all 16channels of capacitive sensors are active, the channel conversion rate is thus
440 Hz/16 = 27.5 Hz (Min), 14 kHz/16 = 875 Hz (Max)
Using the maximum MAF setting (18 remove 2), the maximum filtered channel output rate is
875 Hz/18 = 48.6 Hz.
Doc ID 17058 Rev 2
STMPE16M31PX