Datasheet
ST72321Rx ST72321ARx ST72321Jx
141/193
OPERATING CONDITIONS (Cont’d)
12.3.2 Operating Conditions with Low Voltage Detector (LVD)
Subject to general operating conditions for V
DD
, f
CPU
, and T
A
.
Notes:
1. Data based on characterization results, tested in production for ROM devices only.
2. If the medium or low thresholds are selected, the detection may occur outside the specified operating voltage range.
Below 3.8V, device operation is not guaranteed.
3. Data based on characterization results, not tested in production.
3. When Vt
POR
is faster than 100 μs/V, the Reset signal is released after a delay of max. 42µs after V
DD
crosses the
V
IT+(LVD)
threshold.
12.3.3 Auxiliary Voltage Detector (AVD) Thresholds
Subject to general operating conditions for V
DD
, f
CPU
, and T
A
.
1. Data based on characterization results, tested in production for ROM devices only.
12.3.4 External Voltage Detector (EVD) Thresholds
Subject to general operating conditions for V
DD
, f
CPU
, and T
A
.
1. Data based on characterization results, not tested in production.
Symbol Parameter Conditions Min Typ
Max Unit
V
IT+(LVD)
Reset release threshold
(V
DD
rise)
VD level = High in option byte 4.0
1)
4.2 4.5
V
VD level = Med. in option byte
2)
VD level = Low in option byte
2)
3.55
1)
2.95
1)
3.75
3.15
4.0
1)
3.35
1)
V
IT-(LVD)
Reset generation threshold
(V
DD
fall)
VD level = High in option byte 3.8 4.0 4.25
1)
VD level = Med. in option byte
2)
VD level = Low in option byte
2)
3.35
1)
2.8
1)
3.55
3.0
3.75
1))
3.15
1)
V
hys(LVD)
LVD voltage threshold hysteresis
V
IT+(LVD)
-V
IT-(LVD)
200 mV
Vt
POR
V
DD
rise time
3)2)
LVD enabled 6μs/V 100ms/V
t
g(VDD)
V
DD
glitches filtered (not detect-
ed) by LVD
3)
40 ns
Symbol Parameter Conditions Min Typ Max Unit
V
IT+(AVD)
1 ⇒ 0 AVDF flag toggle threshold
(V
DD
rise)
VD level = High in option byte 4.4
1)
4.6 4.9
1)
V
VD level = Med. in option byte
VD level = Low in option byte
3.95
1)
3.4
1)
4.15
3.6
4.4
1)
3.8
1)
V
IT-(AVD)
0 ⇒ 1 AVDF flag toggle threshold
(V
DD
fall)
VD level = High in option byte 4.2
1)
4.4 4.65
1)
VD level = Med. in option byte
VD level = Low in option byte
3.75
1)
3.2
1)
4.0
3.4
4.2
1)
3.6
1)
V
hys(AVD)
AVD voltage threshold hysteresis V
IT+(AVD)
-V
IT-(AVD)
200 mV
ΔV
IT-
Voltage drop between AVD flag set
and LVD reset activated
V
IT-(AVD)
-V
IT-(LVD)
450 mV
Symbol Parameter Conditions Min Typ Max Unit
V
IT+(EVD)
1 ⇒ 0 AVDF flag toggle threshold
(V
DD
rise)
1)
1.15 1.26 1.35
V
V
IT-(EVD)
0 ⇒ 1 AVDF flag toggle threshold
(V
DD
fall)
1)
1.1 1.2 1.3
V
hys(EVD)
EVD voltage threshold hysteresis V
IT+(EVD)
-V
IT-(EVD)
200 mV