34.13 PTC Characteristics
| Symbol | Mode | PTC channel | Max Sensor Load (1) | Units |
|---|---|---|---|---|
| CLOAD | Self-capacitance | Y0 | 15 | pf |
| Y1 | 22 | |||
| Y2 | 18 | |||
| Y3 | 22 | |||
| Y4 | ||||
| Y5 | ||||
| Y6 | ||||
| Y7 | ||||
| Y8 | ||||
| Y9 | ||||
| Y10 | ||||
| Y11 | ||||
| Y12 | ||||
| Y13 | ||||
| Y14 | ||||
| Y15 | ||||
| Mutual-capacitance | All | 29 |
- Capacitance load that the PTC circuitry can compensate for each channel.
| Symbol | Setting | Average |
|---|---|---|
| Gain | GAIN_1 | 1.0 |
| GAIN_2 | 2.0 | |
| GAIN_4 | 3.8 | |
| GAIN_8 | 7.8 | |
| GAIN_16 | 12.8 | |
| GAIN_32 | - |
- Analog Gain is a parameter of the QTouch Library. Refer to the QTouch Library Peripheral Touch Controller User Guide.
- GAIN_16 and GAIN_32 settings are not recommended, otherwise the PTC measurements might get unstable.
Power Consumption
The values provided in the Power Consumption table below are measured values of power consumption under the following conditions:
Operating Conditions:
VDD = 3.3V
Clocks:
OSC8M used as main clock source, running undivided at 8 MHz.
CPU is running on flash with 0 wait states, at 8 MHz.
PTC running at 4 MHz.
PTC Configuration:
Mutual-Capacitance mode
One touch channel
System Configuration:
Standby Sleep mode enabled.
RTC running on OSCULP32K: used to define the PTC scan rate through the event system.
Drift Calibration disabled: no interrupts, PTC scans are performed in Standby mode.
Drift Calibration enabled: RTC interrupts (wakeup) the CPU to perform PTC scans. PTC drift calibration is performed every 1.5 sec.
| Symbol | Parameters | Drift Calibration | PTC scan rate (msec) | Oversamples | Ta | Typ. | Max. | Units |
|---|---|---|---|---|---|---|---|---|
| IDD (2) | Current Consumption | Disabled | 10 | 4 | Max. 125°C Typ. 25°C | 67 | 487 | µA |
| 16 | 75 | 498 | ||||||
| 50 | 4 | 62 | 481 | |||||
| 16 | 64 | 484 | ||||||
| 100 | 4 | 62 | 481 | |||||
| 16 | 63 | 482 | ||||||
| 200 | 4 | 61 | 481 | |||||
| 16 | 62 | 482 | ||||||
| Enabled | 10 | 4 | 71 | 495 | ||||
| 16 | 79 | 507 | ||||||
| 50 | 4 | 64 | 485 | |||||
| 16 | 65 | 489 | ||||||
| 100 | 4 | 63 | 485 | |||||
| 16 | 64 | 487 | ||||||
| 200 | 4 | 62 | 484 | |||||
| 16 | 63 | 484 |
- These values are based on characterization.
- On this table, the LDO Voltage Regulator is enabled in Standby mode (SYSCTRL.VREG.RUNSTDBY = 1).