K20P81M72SF1 Datasheet, PDF (65/74 Pages) Freescale Semiconductor, Inc – K20 Sub-Family

Table 47. 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
—
2.5
Unit
Notes
μs
12
μA
μA
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. V_DD = 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, 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 = 6 μA (EXTCHRG = 2), PS = 128, NSCN = 2, I_ref = 16 μA (REFCHRG = 7), 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 = 2 μA (EXTCHRG = 0), PS = 128, NSCN = 32, I_ref = 32 μA (REFCHRG = 15).
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.
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
80-pin LQFP
81-pin MAPBGA
Then use this document number
98ASS23174W
98ASA00344D
8 Pinout
K20 Sub-Family Data Sheet, Rev. 2, 4/2012.
Freescale Semiconductor, Inc.
65