LTC3246

4

3246fa

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 voltages are referenced to GND unless otherwise specified.

Note 3: The LTC3246E is guaranteed to meet performance specifications

from 0°C to 85°C operating junction temperature. Specifications over

the –40°C to 125°C operating junction temperature range are assured by

design, characterization and correlation with statistical process controls.

The LTC3246I is guaranteed over the –40°C to 125°C operating junction

temperature range. The LTC3246H is guaranteed over the –40°C to 150°C

operating junction temperature range. The LTC3246MP is guaranteed and

tested over the –55°C to 150°C operating junction temperature range.

High junction temperatures degrade operating lifetimes; operating lifetime

is derated for junction temperatures greater than 125°C. Note that the

maximum ambient temperature consistent with these specifications is

determined by specific operating conditions in conjunction with board

layout, the rated package thermal resistance and other environmental

factors.

TYPICAL PERFORMANCE CHARACTERISTICS

Input Shutdown Current

vs Input Voltage

Input Operating Current

vs Input Voltage

Input Operating Current

vs Input Voltage

the formula:

impedance.

Note 4: This IC has overtemperature protection that is intended to protect

the device during momentary overload conditions. Junction temperatures

will exceed 150°C when overtemperature protection is active. Continuous

operation above the specified maximum operating junction temperature

may impair device reliability.

Note 5: The maximum operating junction temperature of 150°C must

be followed. Certain combinations of input voltage, output current and

ambient temperature will cause the junction temperature to exceed 150°C

and must be avoided. See Thermal Management section for information on

calculating maximum operating conditions.

Note 6: The LTC3246 will attempt to regulate the output voltage under

all load conditions, but like any regulator, the output will drop out if

for calculating available load current at low input operating voltages. Also

see “Boost Output Impedance at Dropout vs Temperature” for typical

impedance values at output voltages less than 3.3V.

0

4

8 12 16 20 24 28 32 36 40

0

1

2

3

4

5

6

7

8

9

10

3246 G01

0

5

10

15

20

25

30

35

40

10

100

1000

3246 G02

NO LOAD

125°C

25°C

–55°C

4

6

8

10

12

14

16

0

10

20

30

40

50

60

3246 G03

NO LOAD

SYMBOL

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

Watchdog Timer Control Pin (WT)

WT Pull-Up Current

l

–2

–3.1

–4.2

µA

WT Pull-Down Current

l

2

3.1

4.2

µA

Internal WT Detect Current

l

0.4

1

µA

WT Internal Timer Threshold

l

2

2.2

2.65

V

l

denotes the specifications which apply over the specified operating