LM3712 Datasheet, PDF (6/13 Pages) National Semiconductor (TI) – Microprocessor Supervisory Circuits with Separate Watchdog Timer Output, Power Fail Input and Manual Reset

LM3712/LM3713 Series Electrical Characteristics (Continued)
Limits in the standard typeface are for T_J = 25˚C and limits in boldface type apply over full operating range. Unless otherwise
specified: V_CC = +2.2V to 5.5V.
Symbol
Parameter
Conditions
Min
Typ
Max Units
WDI
WDI
Watchdog Input
−1
+1
µA
Current
WDI_T
Watchdog Input
Threshold
0.2•V_CC
1.225
0.8•V_CC
V
t_WD
Watchdog
Watchdog Timeout Period = E, F, G, H
Timeout Period
Watchdog Timeout Period = J, K, L, M
Watchdog Timeout Period = N, P, Q, R
4.3
71
1120
6.2
102
1600
9.3
153
ms
2400
Watchdog Timeout Period = S, T, U, V
17900
25600
38400
PFI/MR
V_PFT
PFI Input
Threshold
1.200
1.225
1.250
V
V_MRT
MR Input
Threshold
MR, Low
MR, High
0.8
V
2.0
V_PFTH/
V_MRTH
I_PFI
PFI/MR Threshold
Hysteresis
Input Current (PFI
only)
PFI/MR falling: V_CC = V_{RST MAX} to 5.5V
0.0032•V_RST
mV
−75
75
nA
R_MR
MR Pull-up
Resistance
35
56
75
kΩ
t_MD
MR to Reset
Delay
12
µS
t_MR
MR Pulse Width
PFO, WDO
V_OL
PFO, WDO
Output Voltage
V_OH
LLO OUTPUT
V_CC > 2.25V, I_SINK = 900µA
V_CC > 2.7V, I_SINK = 1.2mA
V_CC > 4.5V, I_SINK = 3.2mA
V_CC > 2.25V, I_SOURCE = 300µA
V_CC > 2.7V, I_SOURCE = 500µA
V_CC > 4.5V, I_SOURCE = 800µA
25
0.8 V_CC
0.8 V_CC
V_CC − 1.5V
µS
0.3
0.3
0.4
V
V_LLOT
LLO Output
Threshold
(V_LLO − V_RST, V_CC
falling)
1.01•V_RST
1.02•V_RST 1.03•V_RST
V
V_LLOTH
Low-Line
Comparator
0.0032•V_RST
mV
Hysteresis
t_CD
Low-Line
V_CC falling at 1mV/µs
Comparator Delay
20
µs
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