Datasheet

  
  
SLAS491A − AUGUST 2005 − REVISED OCTOBER 2005
26
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
electrical characteristics over recommended ranges of supply voltage and operating free-air
temperature (unless otherwise noted) (continued)
POR/brownout reset (BOR) (see Notes 1 and 2)
PARAMETER TEST CONDITIONS VCC MIN TYP MAX UNIT
V
CC(start)
(see Figure 8) dV
CC
/dt ≤ 3 V/s 0.7 × V
(B_IT−)
V
V
(B_IT−)
(see Figure 8 through Figure 10) dV
CC
/dt ≤ 3 V/s 1.71 V
V
hys(B_IT−)
(see Figure 8) dV
CC
/dt ≤ 3 V/s 70 130 180 mV
t
d(BOR)
(see Figure 8) 2000 µs
t
(reset)
Pulse length needed at RST/NMI pin
to accepted reset internally
2.2 V/3 V 2 µs
NOTES: 1. The current consumption of the brownout module is already included in the I
CC
current consumption data. The voltage level V
(B_IT−)
+ V
hys(B_IT−)
is ≤ 1.8V.
2. During power up, the CPU begins code execution following a period of t
d(BOR)
after V
CC
= V
(B_IT−)
+ V
hys(B_IT−)
. The default
DCO settings must not be changed until V
CC
≥ V
CC(min)
, where V
CC(min)
is the minimum supply voltage for the desired
operating frequency.
0
1
t
d(BOR)
V
CC
V
(B_IT−)
V
hys(B_IT−)
V
CC(start)
Figure 8. POR/Brownout Reset (BOR) vs Supply Voltage