LTC1235CS Linear Technology, LTC1235CS Datasheet - Page 4

• Manufacturer Part Number: LTC1235CS
• Manufacturer: Linear Technology

Specifications of LTC1235CS

• Number Of Elements: 1
• Monitored Voltage 1 (typ): 4.65V
• Battery Backup Switching: Yes
• Watchdog Timer: Yes
• Chip Enable Signals: Yes
• Reset Active Time: 280ms
• Manual Reset: Yes
• Package Type: SOL
• Operating Supply Voltage (min): 4.75V
• Operating Supply Voltage (max): 5.5V
• Reset Threshold Voltage (max): 4.75V
• Reset Threshold Voltage (min): 4.5V
• Power Dissipation: 500mW
• Operating Temp Range: 0C to 70C
• Operating Temperature Classification: Commercial
• Power Fail Detection: Yes
• Mounting: Surface Mount
• Pin Count: 16
• Supply Current: 1.5mA
• Lead Free Status / Rohs Status: Not Compliant

temperature range, otherwise specifi cations are at T
T
LTC1235
ELECTRICAL CHARACTERISTICS
PARAMETER
RESET, RESET, WDO, LOW LINE
WDI Input Threshold
WDI Input Current
Power Fail Detector
PFI Input Threshold
PFI Input Threshold PSRR
PFI Input Current
PFO Output Voltage (Note 6)
PFO Short Circuit Source Current
PFI Comparator Response Time (falling)
PFI Comparator Response Time (rising)
Chip Enable Gating
CE IN Threshold
CE IN Pullup Current (Note 4)
CE OUT Output Voltage
CE Propagation Delay
CE OUT Output Short Circuit Current
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 voltage values are with respect to GND.
Note 3: For military temperature range parts, consult the factory.
Note 4: The input pins of PB RST, BACKUP and CE IN, have weak internal
pullups which pull to the supply when the input pins are fl oating.
Note 5: The LTC1235 can be programmed either to provide or not to
provide battery backup power to the V
The power down condition of V
BACKUP pin which is latched internally when V
voltage threshold. If the latched logic level of the BACKUP pin is high,
4
A
= 25°C, unless otherwise noted.
Output Short Circuit Current (Note 6)
(Note 6)
(Note 6)
OUT
is selected by the logic level of the
OUT
pin during power failure.
CC
falls through the reset
CONDITIONS
Output Source Current
Output Sink Current
Logic Low
Logic High
WDI = V
WDI = 0V
V
I
I
PFI = HIGH, PFO = 0V
PFI = LOW, PFO = V
ΔV
ΔV
with 10kΩ Pullup
V
V
I
I
I
V
Output Source Current
Output Sink Current
SINK
SOURCE
SINK
SOURCE
SOURCE
CC
IL
IH
CC
IN
IN
= 5V
= 5V, CL = 20pF
A
= –20mV, V
= 20mV, V
= 3.2mA
= 3.2mA
= 25°C. V
OUT
= 1A
= 3.0mA
= 1μA, V
The
OD
l
OD
CC
CC
denotes the specifi cations which apply over the full operating
= 15mV
OUT
= 0V
= 15mV
= Full Operating Range, V
V
V
V
Note 6: The output pins of BATT ON, LOW LINE, PFO, WDO, RESET and
RESET have weak internal pullups of typically 3A. However, external
pullup resistors may be used when higher speed is required.
Note 7: The push-button reset input requires an active low signal.
Internally, this input signal is debounced and timed for a minimum of
40ms. When this condition is satisfi ed, the reset outputs go to the active
states. The reset outputs will remain in active states for a minimum of
140ms from the moment the push-button reset input is released from
logic low level.
OUT
CC
OUT
falls below V
will be in Battery Backup Mode and will be switched to V
will be in Battery Saving Mode when V
BATT
l
l
l
l
. If the latched logic level of the BACKUP pin is low,
V
V
OUT
OUT
BATT
1.25
MIN
–50
2.0
3.5
2.0
1
1
– 1.50
– 0.05
= 2.8V, Backup = No Connection,
±0.01
TYP
1.3
0.3
–8
25
30
40
20
20
30
35
3
4
3
2
8
3
CC
falls below V
MAX
1.35
±25
0.8
0.4
0.8
0.4
25
50
25
35
45
BATT
BATT
.
UNITS
when
mV/V
1235fa
mA
mA
mA
mA
μA
μA
μA
nA
μA
μA
μs
μs
μs
ns
ns
V
V
V
V
V
V
V
V
V
V