Datasheet

6.9 Human-machine interfaces (HMI)
6.9.1 TSI electrical specifications
Table 52. TSI electrical specifications
Symbol Description Min. Typ. Max. Unit Notes
V
DDTSI
Operating voltage 1.71 — 3.6 V
C
ELE
Target electrode capacitance range 1 20 500 pF 1
f
REFmax
Reference oscillator frequency — 5.5 12.7 MHz 2
f
ELEmax
Electrode oscillator frequency — 0.5 4.0 MHz 3
C
REF
Internal reference capacitor 0.5 1 1.2 pF
V
DELTA
Oscillator delta voltage 100 600 760 mV 4
I
REF
Reference oscillator current source base current
• 1uA setting (REFCHRG=0)
• 32uA setting (REFCHRG=31)
—
—
1.133
36
1.5
50
μA 3 , 5
I
ELE
Electrode oscillator current source base current
• 1uA setting (EXTCHRG=0)
• 32uA setting (EXTCHRG=31)
—
—
1.133
36
1.5
50
μA 3 , 6
Pres5 Electrode capacitance measurement precision — 8.3333 38400 fF/count 7
Pres20 Electrode capacitance measurement precision — 8.3333 38400 fF/count 8
Pres100 Electrode capacitance measurement precision — 8.3333 38400 fF/count 9
MaxSens Maximum sensitivity 0.003 12.5 — fF/count 10
Res Resolution — — 16 bits
T
Con20
Response time @ 20 pF 8 15 25 μs 11
I
TSI_RUN
Current added in run mode — 55 — μA
I
TSI_LP
Low power mode current adder — 1.3 2.5 μA 12
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 (C
ref
* I
ext
)/( I
ref
* 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, I
ref
= 16 μA, REFCHRG = 15, C
ref
= 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: I
ext
= 1 μA, EXTCHRG = 0, PS = 128, NSCN = 32, I
ref
= 32 μA, REFCHRG = 31, C
ref
= 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
K60 Sub-Family Data Sheet Data Sheet, Rev. 7, 02/2013.
Freescale Semiconductor, Inc. 67