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K10P64M50SF0 Datasheet, PDF (53/61 Pages) Freescale Semiconductor, Inc – K10 Sub-Family
Peripheral operating requirements and behaviors
Table 38. TSI electrical specifications (continued)
Symbol Description
fREFmax Reference oscillator frequency
fELEmax Electrode oscillator frequency
CREF Internal reference capacitor
VDELTA Oscillator delta voltage
IREF Reference oscillator current source base current
• 2 μA setting (REFCHRG = 0)
• 32 μA setting (REFCHRG = 15)
IELE Electrode oscillator current source base current
• 2 μA setting (EXTCHRG = 0)
• 32 μA setting (EXTCHRG = 15)
Pres5 Electrode capacitance measurement precision
Pres20 Electrode capacitance measurement precision
Pres100 Electrode capacitance measurement precision
MaxSens Maximum sensitivity
Res Resolution
TCon20 Response time @ 20 pF
ITSI_RUN Current added in run mode
ITSI_LP Low power mode current adder
Min.
—
—
—
—
—
—
—
—
—
—
—
0.008
—
8
—
—
Typ.
8
1
1
500
2
36
2
36
8.3333
8.3333
8.3333
1.46
—
15
55
1.3
Max.
15
1.8
—
—
3
50
3
50
38400
38400
38400
—
16
25
—
2.5
Unit
MHz
MHz
pF
mV
μA
μA
fF/count
fF/count
fF/count
fF/count
bits
μs
μA
μA
Notes
2, 3
2, 4
2, 5
2, 6
2, 7
8
9
10
11
12
13
1. The TSI module is functional with capacitance values outside this range. However, optimal performance is not guaranteed.
2. Fixed external capacitance of 20 pF.
3. REFCHRG = 2, EXTCHRG=0.
4. REFCHRG = 0, EXTCHRG = 10.
5. VDD = 3.0 V.
6. The programmable current source value is generated by multiplying the SCANC[REFCHRG] value and the base current.
7. The programmable current source value is generated by multiplying the SCANC[EXTCHRG] value and the base current.
8. Measured with a 5 pF electrode, reference oscillator frequency of 10 MHz, PS = 128, NSCN = 8; Iext = 16.
9. Measured with a 20 pF electrode, reference oscillator frequency of 10 MHz, PS = 128, NSCN = 2; Iext = 16.
10. Measured with a 20 pF electrode, reference oscillator frequency of 10 MHz, PS = 16, NSCN = 3; Iext = 16.
11. Sensitivity defines the minimum capacitance change when a single count from the TSI module changes. Sensitivity
depends on the configuration used. The documented values are provided as examples calculated for a specific
configuration of operating conditions using the following equation: (Cref * Iext)/( Iref * PS * NSCN)
The typical value is calculated with the following configuration:
Iext = 6 μA (EXTCHRG = 2), PS = 128, NSCN = 2, Iref = 16 μA (REFCHRG = 7), Cref = 1.0 pF
The minimum value is calculated with the following configuration:
Iext = 2 μA (EXTCHRG = 0), PS = 128, NSCN = 32, Iref = 32 μA (REFCHRG = 15), Cref = 0.5 pF
The highest possible sensitivity is the minimum value because it represents the smallest possible capacitance that can be
measured by a single count.
12. Time to do one complete measurement of the electrode. Sensitivity resolution of 0.0133 pF, PS = 0, NSCN = 0, 1
electrode, EXTCHRG = 7.
13. 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.
K10 Sub-Family Data Sheet, Rev. 4 5/2012.
Freescale Semiconductor, Inc.
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