Datasheet

Power-On Reset
t
DEVICE_READY
1.2Vto3.6V
0.9V
0.3V
0V
V
DD
t
VDD_OFF_RAMP
t
VDD_OFF
t
VDD_ON_RAMP
Temperature( C)°
V OffTimeforValidPOR(s)
DD
-40 -20
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
0 20 40 60 80 100
RecommendedV OffTime
forT = 40 Cto+85 C- ° °
DD
A
TypicalV OffTimeforVariousTemperatures
DD
TSC2008
SBAS406B – JUNE 2008 – REVISED MARCH 2009 .......................................................................................................................................................... www.ti.com
During TSC2008 power up, an internal power-on reset (POR) is triggered if the power-supply ramping meets the
timing requirements shown in Figure 37 and listed in Table 9 . The recommended and typical V
DD
off times are
shown in Figure 38 . The POR brings the TSC2008 to the default working condition. If the system is not able to
meet the power ramping timing requirements, or if the system is not properly reset (even after a POR), then
including the SureSet reset in the initialization routine is recommended.
Figure 37. Power-On Reset Timing
Table 9. Timing Requirements for Figure 37
PARAMETER TEST CONDITIONS MIN MAX UNIT
t
VDD_OFF_RAMP
T
A
= – 40 ° C to +85 ° C 2 kV/s
T
A
= – 40 ° C to +85 ° C 1 s
t
VDD_OFF
T
A
= – 20 ° C to +85 ° C 0.3 s
t
VDD_ON_RAMP
T
A
= – 40 ° C to +85 ° C 12 kV/s
t
DEVICE_READY
T
A
= – 40 ° C to +85 ° C 2 ms
Figure 38. V
DD
Off Time vs Temperature
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Product Folder Link(s): TSC2008