LTC2908
ELECTRICAL CHARACTERISTICS
SYMBOL
V
CC
I
V1
I
V2
I
V3
I
V4
I
VADJ
t
RST
t
UV
V
OH
V
OL
PARAMETER
Internal Operating Voltage
V1 Input Current
V2 Input Current
V3 Input Current
V4 Input Current
V
ADJ1
, V
ADJ2
Input Current
Reset Time-Out Period
V
X
Undervoltage Detect to RST or RST
Output Voltage High RST (Note 5)
Output Voltage Low RST
The
●
denotes specifications which apply over the full operating
temperature range, otherwise specifications are T
A
= 25°C. V
CC
= 5V for the LT2908-A1 and V
CC
= 3.3V for the LTC2908-B1, unless
otherwise noted. (Notes 2, 3)
CONDITIONS
RST in Correct Logic State
V1 = 5.0V (LTC2908-A1) (Note 4)
V1 = 3.3V (LTC2908-B1)
V2 = 3.3V (LTC2908-A1) (Note 4)
V2 = 2.5V (LTC2908-B1)
V3 = 2.5V (LTC2908-A1)
V3 = 1.8V (LTC2908-B1)
V4 = 1.8V (LTC2908-A1)
V4 = 1.5V (LTC2908-B1)
V
ADJ1
= V
ADJ2
= 0.55V
V
X
Less Than Reset Threshold V
RTX
by
More Than 1%
I
RST
= –1µA, V
CC
= 5V (LTC2908-A1)
I
RST
= –1µA, V
CC
= 3.3V (LTC2908-B1)
V
CC
= 0.5V, I
RST
= 5µA
V
CC
= 1.0V, I
RST
= 100µA
V
CC
= 3.0V, I
RST
= 2500µA
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
MIN
0.5
TYP
26
24
10
8
2
2
2
2
MAX
6
50
50
20
20
5
5
5
5
±15
260
UNITS
V
µA
µA
µA
µA
µA
µA
µA
µA
nA
ms
µs
V
V
160
200
250
V
CC
– 1.5
V
CC
– 1.0
0.01
0.01
0.10
0.15
0.15
0.30
V
V
V
Note 1:
Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2:
The greater of V1, V2 is the internal supply voltage (V
CC
).
Note 3:
All currents into pins are positive; all voltages are referenced to
GND unless otherwise noted.
Note 4:
Under typical operating conditions, most of the quiescent current
is drawn from the V1 input. When V2 exceeds V1, V2 supplies most of the
quiescent current.
Note 5:
The output pin RST has an internal pull-up to V
CC
of typically 6µA.
However, an external pull-up resistor may be used when a faster rise time
is required or for V
OH
voltages greater than V
CC
.
TYPICAL PERFOR A CE CHARACTERISTICS
Specifications are at T
A
= 25°C unless otherwise noted.
5V Threshold Voltage
vs Temperature
4.750
THRESHOLD VOLTAGE, V
RT50
(V)
THRESHOLD VOLTAGE, V
RT33
(V)
4.725
4.700
4.675
4.650
4.625
4.600
–50
3.115
THRESHOLD VOLTAGE, V
RT25
(V)
–25
50
25
0
TEMPERATURE (°C)
U W
75
2908 G01
3.3V Threshold Voltage
vs Temperature
3.135
2.375
2.5V Threshold Voltage
vs Temperature
2.360
3.095
2.345
3.075
2.330
3.055
2.315
100
3.035
–50
–25
50
25
0
TEMPERATURE (°C)
75
100
2908 G02
2.300
–50
–25
50
25
0
TEMPERATURE (°C)
75
100
2908 G03
sn2908 2908fs
3
LINEAR [ LINEAR INTEGRATED SYSTEMS ]
