6.9 Human-machine interfaces (HMI)
6.9.1 TSI electrical specifications
Table 48. TSI electrical specifications
Symbol
Description
Min.
Typ.
Max.
Unit
Notes
VDDTSI
Operating voltage
1.71
—
3.6
V
CELE
Target electrode capacitance range
1
20
500
pF
fREFmax
Reference oscillator frequency
—
5.5
12.7
MHz
fELEmax
Electrode oscillator frequency
—
0.5
4.0
MHz
CREF
Internal reference capacitor
0.5
1
1.2
pF
VDELTA
Oscillator delta voltage
100
600
760
mV
IREF
Reference oscillator current source base current
1uA setting (REFCHRG=0)
32uA setting (REFCHRG=31)
—
1.133
36
1.5
50
μA
IELE
Electrode oscillator current source base current
1uA setting (EXTCHRG=0)
32uA setting (EXTCHRG=31)
—
1.133
36
1.5
50
μA
Pres5
Electrode capacitance measurement precision
—
8.3333
38400
fF/count
Pres20
Electrode capacitance measurement precision
—
8.3333
38400
fF/count
Pres100
Electrode capacitance measurement precision
—
8.3333
38400
fF/count
MaxSens Maximum sensitivity
0.003
12.5
—
fF/count
Res
Resolution
—
16
bits
TCon20
Response time @ 20 pF
8
15
25
μs
ITSI_RUN
Current added in run mode
—
55
—
μA
ITSI_LP
Low power mode current adder
—
1.3
2.5
μA
1. The TSI module is functional with capacitance values outside this range. However, optimal performance is not guaranteed.
2. CAPTRM=7, DELVOL=7, and fixed external capacitance of 20 pF.
3. CAPTRM=0, DELVOL=2, and fixed external capacitance of 20 pF.
4. CAPTRM=0, EXTCHRG=9, and fixed external capacitance of 20 pF.
5. The programmable current source value is generated by multiplying the SCANC[REFCHRG] value and the base current.
6. The programmable current source value is generated by multiplying the SCANC[EXTCHRG] value and the base current.
7. Measured with a 5 pF electrode, reference oscillator frequency of 10 MHz, PS = 128, NSCN = 8; Iext = 16.
8. Measured with a 20 pF electrode, reference oscillator frequency of 10 MHz, PS = 128, NSCN = 2; Iext = 16.
9. Measured with a 20 pF electrode, reference oscillator frequency of 10 MHz, PS = 16, NSCN = 3; Iext = 16.
10. Sensitivity defines the minimum capacitance change when a single count from the TSI module changes, it is equal to (Cref
* Iext)/( Iref * PS * NSCN). Sensitivity depends on the configuration used. The typical value listed is based on the following
configuration: Iext = 5 μA, EXTCHRG = 4, PS = 128, NSCN = 2, Iref = 16 μA, REFCHRG = 15, Cref = 1.0 pF. The
minimum sensitivity describes the smallest possible capacitance that can be measured by a single count (this is the best
sensitivity but is described as a minimum because it’s the smallest number). The minimum sensitivity parameter is based
on the following configuration: Iext = 1 μA, EXTCHRG = 0, PS = 128, NSCN = 32, Iref = 32 μA, REFCHRG = 31, Cref= 0.5
pF
11. Time to do one complete measurement of the electrode. Sensitivity resolution of 0.0133 pF, PS = 0, NSCN = 0, 1
electrode, DELVOL = 2, EXTCHRG = 15.
12. CAPTRM=7, DELVOL=2, REFCHRG=0, EXTCHRG=4, PS=7, NSCN=0F, LPSCNITV=F, LPO is selected (1 kHz), and
fixed external capacitance of 20 pF. Data is captured with an average of 7 periods window.
Peripheral operating requirements and behaviors
K10 Sub-Family Data Sheet Data Sheet, Rev. 7, 02/2013.
60
Freescale Semiconductor, Inc.