K20P144M120SF3 Datasheet, PDF (69/80 Pages) Freescale Semiconductor, Inc – K20 Sub-Family Data Sheet

Table 48. TSI electrical specifications (continued)
Dimensions
Symbol
T_Con20
I_{TSI_RUN}
I_{TSI_LP}
Description
Response time @ 20 pF
Current added in run mode
Low power mode current adder
Min.
8
—
—
Typ.
15
55
1.3
Max.
25
—
TBD
Unit
Notes
μs
9
μA
μA
10
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. The programmable current source value is generated by multiplying the SCANC[REFCHRG] value and the base current.
4. The programmable current source value is generated by multiplying the SCANC[EXTCHRG] value and the base current.
5. Measured with a 5 pF electrode, reference oscillator frequency of 10 MHz, PS = 128, NSCN = 8; Iext = 16.
6. Measured with a 20 pF electrode, reference oscillator frequency of 10 MHz, PS = 128, NSCN = 2; Iext = 16.
7. Measured with a 20 pF electrode, reference oscillator frequency of 10 MHz, PS = 16, NSCN = 3; Iext = 16.
8. 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
9. Time to do one complete measurement of the electrode. Sensitivity resolution of 0.0133 pF, PS = 0, NSCN = 0, 1
electrode, EXTCHRG = 15.
10. 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.
7 Dimensions
7.1 Obtaining package dimensions
Package dimensions are provided in package drawings.
To find a package drawing, go to http://www.freescale.com and perform a keyword
search for the drawing’s document number:
If you want the drawing for this package
144-pin LQFP
144-pin MAPBGA
Then use this document number
98ASS23177W
98ASA00222D
8 Pinout
K20 Sub-Family Data Sheet Data Sheet, Rev. 3, 2/2012.
Freescale Semiconductor, Inc.
Preliminary
69