LTC1235

4

1235fa

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

RESET, RESET, WDO, LOW LINE

Output Short Circuit Current (Note 6)

Output Source Current

Output Sink Current

13

25

25

μA

mA

WDI Input Threshold

Logic Low

Logic High

2.0

0.8

V

V

WDI Input Current

WDI = 0V

l

l

–50

4

–8

50

μA

μA

Power Fail Detector

PFI Input Threshold

l

1.25

1.3

1.35

V

PFI Input Threshold PSRR

0.3

mV/V

PFI Input Current

±0.01

±25

nA

PFO Output Voltage (Note 6)

3.5

0.4

V

V

PFO Short Circuit Source Current

(Note 6)

PFI = HIGH, PFO = 0V

13

30

25

μA

mA

PFI Comparator Response Time (falling)

2

μs

PFI Comparator Response Time (rising)

(Note 6)

with 10kΩ Pullup

40

8

μs

μs

Chip Enable Gating

CE IN Threshold

2.0

0.8

V

V

CE IN Pullup Current (Note 4)

3μA

CE OUT Output Voltage

0.4

V

V

V

CE Propagation Delay

l

20

20

35

45

ns

ns

CE OUT Output Short Circuit Current

Output Source Current

Output Sink Current

30

35

mA

mA

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 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 floating.

Note 5: The LTC1235 can be programmed either to provide or not to

voltage threshold. If the latched logic level of the BACKUP pin is high,

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 satisfied, 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.

The