Datasheet
LTC2909
3
2909fb
The ● denotes the specifi cations which apply over the full operating
temperature range, otherwise specifi cations are at T
A
= 25°C. V
CC
= 2.5V (LTC2909-2.5), V
CC
= 3.3V (LTC2909-3.3), V
CC
= 5V
(LTC2909-5), ADJ1 = ADJ2 = 0.55V, SEL = fl oating, unless otherwise noted. (Note 2)
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V
CC(MIN)
Operating Supply Voltage
⎯
R
⎯
S
⎯
T in Correct State
●
0.5 V
V
CC(SHUNT)
V
CC
Shunt Regulation Voltage I
VCC
= 1mA, I
VREF
= 0
●
6.0 6.5 6.9 V
I
CC
V
CC
Input Current 2.175 < V
CC
< 6V
●
50 150 µA
V
RT
ADJ Input Threshold
●
0.4925 0.5000 0.5075 V
ΔV
RT
ADJ Hysteresis (Note 4) TMR = V
CC
1.5 3.5 10.0 mV
I
ADJ
ADJ Input Current V
ADJ
= 0.55V
●
±15 nA
V
CC(UVLO)
V
CC
UVLO Threshold LTC2909-2.5
LTC2909-3.3
LTC2909-5
●
●
●
2.175
2.871
4.350
2.213
2.921
4.425
2.250
2.970
4.500
V
V
V
ΔV
CC(UVLO)
UVLO Hysteresis (Note 4) TMR = V
CC
0.3 0.7 2.0 %
V
REF
Buffered Reference Voltage V
CC
> 2.175V, I
VREF
= ±1mA
●
0.985 1.000 1.015 V
I
TMR(UP)
TMR Pull-Up Current V
TMR
= 1V
●
–1.5 –2.1 –2.7 µA
I
TMR(DOWN)
TMR Pull-Down Current V
TMR
= 1V
●
1.5 2.1 2.7 µA
t
⎯
R
⎯
S
⎯
T(EXT)
Reset Timeout Period, External C
TMR
= 2.2nF
●
16 20 25 ms
t
⎯
R
⎯
S
⎯
T(INT)
Reset Timeout Period, Internal V
TMR
= 0V
●
150 200 260 ms
V
TMR(DIS)
Timer Disable Voltage V
TMR
Rising
●
V
CC
– 0.36
V
CC
– 0.25
V
CC
– 0.16
V
ΔV
TMR(DIS)
Timer Disable Hysteresis V
TMR
Falling
●
60 110 150 mV
V
TMR(INT)
Timer Internal Mode Voltage V
TMR
Falling
●
0.14 0.21 0.27 V
ΔV
TMR(INT)
Timer Internal Mode Hysteresis V
TMR
Rising
●
40 70 110 mV
t
PROP
ADJx Comparator Propagation Delay
to
⎯
R
⎯
S
⎯
T
ADJx Driven Beyond Reset Threshold
(V
RTX
) by 5mV
●
50 150 500 µs
t
UV
V
CC
Undervoltage Detect to
⎯
R
⎯
S
⎯
TV
CC
Less Than UVLO Threshold
(V
CC(UVLO)
) by 1%
●
50 150 500 µs
V
OL(
⎯
R
⎯
S
⎯
T)
⎯
R
⎯
S
⎯
T Output Voltage Low V
CC
= 0.5V, I = 5µA
V
CC
= 1V, I = 100µA
V
CC
= 3V, I = 2500µA
●
●
●
0.01
0.01
0.10
0.15
0.15
0.30
V
V
V
I
OH(
⎯
R
⎯
S
⎯
T)
⎯
R
⎯
S
⎯
T Output Voltage High Leakage
⎯
R
⎯
S
⎯
T = V
CC
●
±1 µA
Three-State Input SEL
V
IL
Low Level Input Voltage
●
0.4 V
V
IH
High Level Input Voltage
●
1.4 V
V
Z
Pin Voltage when Left in Open State I
SEL
= 0µA 0.9 V
I
SEL(Z)
Allowable Leakage in Open State
●
±5
±10
µA
µA
I
SEL
SEL Input Current SEL = V
CC
or SEL = GND
●
±25 µA
ELECTRICAL CHARACTERISTICS
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2: All currents into pins are positive; all voltages are referenced to
GND unless otherwise noted.
Note 3: V
CC
maximum pin voltage is limited by input current. Since the
V
CC
pin has an internal 6.5V shunt regulator, a low impedance supply
which exceeds 6V may exceed the rated terminal current. Operation
from higher voltage supplies requires a series dropping resistor. See
Applications Information.
Note 4: Threshold voltages have no hysteresis unless the part is in
comparator mode. Hysteresis is one-sided, affecting only invalid-to-valid
transitions. See Applications Information.