Datasheet

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SLAS272F − JULY 2000 − REVISED JUNE 2004
31
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
electrical characteristics over recommended operating free-air temperature (unless otherwise
noted) (continued)
PUC/POR
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
t
(POR_Delay)
Internal time delay to release POR 150 250 µs
V
CC
threshold at which POR
T
A
= −40°C 1.4 1.8 V
V
POR
V
CC
threshold at which POR
release delay time begins
(see Note 1)
T
A
= 25°C 1.1 1.5 V
V
POR
release delay time begins
(see Note 1)
T
A
= 85°C
V
CC
= 2.2 V/3 V
0.8 1.2 V
V
(min)
V
CC
threshold required to
generate a POR (see Note 2)
V
CC
|dV/dt| ≥ 1V/ms
CC
0.2 V
t
(reset)
RST/NMI low time for PUC/POR Reset is accepted internally 2 µs
NOTES: 1. V
CC
rise time dV/dt ≥ 1V/ms.
2. When driving V
CC
low in order to generate a POR condition, V
CC
should be driven to 200mV or lower with a dV/dt equal to or less
than −1V/ms. The corresponding rising V
CC
must also meet the dV/dt requirement equal to or greater than +1V/ms.
VCC
POR
V
t
V
POR
V
(min)
POR
No POR
Figure 10. Power-On Reset (POR) vs Supply Voltage
1.2
1.5
1.8
0.8
1.2
1.4
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
−40 −20
0
20 40 60 80
25°C
T
A
− Temperature − °C
V
POR
− V
Figure 11. V
POR
vs Temperature