Datasheet
LTC1726
3
1726fd
For more information www.linear.com/LTC1726
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
CC3
= 3.3V, V
CC5
= 5V, V
CC25
= 2.5V, V
CCA
= V
CC3
unless otherwise noted.
elecTrical characTerisTics
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V
RT3
Reset Threshold V
CC3
V
CC3
Input Threshold
H-Grade
l
l
3.036
3.023
3.085
3.085
3.135
3.147
V
V
V
RT5
Reset Threshold V
CC5
V
CC5
Input Threshold (5V Version)
H-Grade
l
l
4.600
4.582
4.675
4.675
4.750
4.769
V
V
V
RT25
Reset Threshold V
CC25
V
CC25
Input Threshold (2.5V Version),
l
2.300 2.337 2.375 V
V
RTA
Reset Threshold V
CCA
V
CCA
Input Threshold
H-Grade
l
l
0.985
0.978
1.000
1.000
1.015
1.022
V
V
V
CC
V
CC3
or V
CC5
Operating Voltage RST in Correct Logic State
l
1 7 V
I
VCC3
V
CC3
Supply Current V
CC5
/V
CC25
> V
CC3
V
CC5
/V
CC25
< V
CC3
, V
CC3
= 3.3V
l
l
1
16
2
30
µA
µA
I
VCC5
V
CC5
Supply Current V
CC5
= 5V
l
16 30 µA
I
VCC25
V
CC25
Supply Current V
CC25
< V
CC3
, V
CC25
= 2.5V (Note 4)
l
1 2 µA
I
VCCA
V
CCA
Input Current V
CCA
= 1V
l
–15 0 15 nA
RT Charge Current Out V
RT
= 0V
H-Grade
l
l
1.4
1.3
2
2
2.6
2.6
µA
µA
WT Charge Current Out V
WT
= 0V
H-Grade
l
l
1.4
1.3
2
2
2.6
2.6
µA
µA
RT Discharge Current Out V
RT
= 1.3V
H-Grade
l
l
14
13
20
20
26
28
µA
µA
WT Discharge Current Out V
WT
= 1.3V
H-Grade
l
l
14
13
20
20
26
28
µA
µA
∆t
RT
Reset Time-Out Period Variation C
RT
= 1500pF Deviation from t
RT
= 5ms (Note 5)
H-Grade
l
l
–30
–45
0
0
30
45
%
%
t
UV
V
CC
Undervoltage Detect to RST V
CC25
/V
CC5
, V
CC3
or V
CCA
Less Than Reset
Threshold V
RT
by More Than 1%
130 µs
V
OH
RST Output Voltage High (Note 6) I
SOURCE
= 1µA
l
V
CC3
– 1 V
V
OL
RST Output Voltage Low I
SINK
= 2.5mA, V
CC5
/V
CC25
= 0V
I
SINK
= 100µA, V
CC3
= 1V, V
CC5
/V
CC25
= 0V
I
SINK
= 100µA, V
CC3
= 0V, V
CC5
/V
CC25
= 1V
I
SINK
= 100µA, V
CC3
= 1V, V
CC5
/V
CC25
= 1V
l
l
l
l
0.15
0.05
0.05
0.05
0.4
0.3
0.3
0.3
V
V
V
V
V
IH
WDI Input Threshold High
l
0.7 • V
CC3
V
V
IL
WDI Input Threshold Low
l
0.3 • V
CC3
V
t
WP
WDI Pulse Width
l
40 ns
∆t
WT
Watchdog Time-Out Period Variation C
WT
= 1500pF Deviation from t
WT
= 33ms (Note 5)
H-Grade
l
l
–30
–45
0
0
30
45
%
%
WDI Leakage Current
l
±1 µA
LTC1726-5 Only
V
OVR
V
CC5
Reset Override Voltage (Note 7) Override V
CC5
Ability to Assert RST V
CC3
±0.025 V