K20P81M72SF1 Datasheet, PDF (12/74 Pages) Freescale Semiconductor, Inc – K20 Sub-Family

General
3. All analog pins are internally clamped to V_SS and V_DD through ESD protection diodes. If V_IN is greater than V_{AIO_MIN}
(=V_SS-0.3V) and V_IN is less than V_{AIO_MAX}(=V_DD+0.3V) is observed, then there is no need to provide current limiting
resistors at the pads. If these limits cannot be observed then a current limiting resistor is required. The negative DC
injection current limiting resistor is calculated as R=(V_{AIO_MIN}-V_IN)/|I_IC|. The positive injection current limiting resistor is
calcualted as R=(V_IN-V_{AIO_MAX})/|I_IC|. Select the larger of these two calculated resistances.
5.2.2 LVD and POR operating requirements
Table 2. V_DD supply LVD and POR operating requirements
Symbol
V_POR
V_LVDH
Description
Falling VDD POR detect voltage
Falling low-voltage detect threshold — high
range (LVDV=01)
Min.
Typ.
Max.
Unit
0.8
1.1
1.5
V
2.48
2.56
2.64
V
Low-voltage warning thresholds — high range
V_LVW1H
V_LVW2H
V_LVW3H
V_LVW4H
• Level 1 falling (LVWV=00)
• Level 2 falling (LVWV=01)
• Level 3 falling (LVWV=10)
• Level 4 falling (LVWV=11)
2.62
2.70
2.78
V
2.72
2.80
2.88
V
2.82
2.90
2.98
V
2.92
3.00
3.08
V
V_HYSH Low-voltage inhibit reset/recover hysteresis —
—
±80
—
mV
high range
V_LVDL Falling low-voltage detect threshold — low range 1.54
1.60
1.66
V
(LVDV=00)
Low-voltage warning thresholds — low range
V_LVW1L
V_LVW2L
V_LVW3L
V_LVW4L
• Level 1 falling (LVWV=00)
• Level 2 falling (LVWV=01)
• Level 3 falling (LVWV=10)
• Level 4 falling (LVWV=11)
1.74
1.80
1.86
V
1.84
1.90
1.96
V
1.94
2.00
2.06
V
2.04
2.10
2.16
V
V_HYSL Low-voltage inhibit reset/recover hysteresis —
—
±60
—
mV
low range
V_BG Bandgap voltage reference
0.97
1.00
1.03
V
t_LPO Internal low power oscillator period — factory
900
1000
1100
μs
trimmed
1. Rising thresholds are falling threshold + hysteresis voltage
Table 3. VBAT power operating requirements
Symbol Description
V_{POR_VBAT} Falling VBAT supply POR detect voltage
Min.
Typ.
Max.
Unit
0.8
1.1
1.5
V
Notes
1
1
Notes
K20 Sub-Family Data Sheet, Rev. 2, 4/2012.
12
Freescale Semiconductor, Inc.