Information

48.7 Functional descriptions
This section provides functional description of the TSI module.
48.7.1 Capacitance measurement
The electrode pin capacitance measurement uses a dual oscillator approach. The TSI
electrode oscillator has its frequency dependable of the external electrode capacitance
and of the TSI module configuration. After going to a configurable prescaler, the TSI
electrode oscillator signal goes to the input of the module counter. The time for the
module counter to reach its module value is measured using the TSI reference oscillator.
The measured electrode capacitance is directly proportional to the time.
Figure 48-32. Dual Electrode Capacitance Measurement
Functional descriptions
K20 Sub-Family Reference Manual, Rev. 2, Feb 2012
1204 Freescale Semiconductor, Inc.