LTC3621/LTC3621-2

5

Rev. D

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ELECTRICAL CHARACTERISTICS The

l

denotes the specifications which apply over the specified operating

junction temperature range, otherwise specifications are at TJ = 25°C. (Note 3) VIN = 12V, unless otherwise noted.

SYMBOL

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

fOSC

Oscillator Frequency

LTC3621/LTC3621-3.3/LTC3621-5

(E/I-Grade)

(H-Grade)

l

l

0.92

0.82

0.78

1.00

1.08

1.16

1.16

MHz

MHz

MHz

LTC3621-2/LTC3621-23.3/LTC3621-25

(E/I-Grade)

(H-Grade)

l

l

2.05

1.8

1.7

2.25

2.45

2.6

2.6

MHz

MHz

MHz

fSYNC

SYNC Capture Range

60

140

%

VINTVCC

VINTVCC LDO Output Voltage

VIN > 4V

3.6

V

ΔVPGOOD

Power Good Range

±7.5

±12.5

%

RPGOOD

Power Good Resistance

PGOOD RDS(ON) at 500µA

275

350

Ω

tPGOOD

PGOOD Delay

PGOOD Low to High

PGOOD High to Low

0

32

Cycles

Cycles

IPGOOD

PGOOD Leakage Current

100

nA

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: Transient absolute maximum voltages should not be applied for

more than 4% of the switching duty cycle.

Note 3: The LTC3621 is tested under pulsed load conditions such that

TJ ≈ TA. The LTC3621E is guaranteed to meet specifications from

0°C to 85°C 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

LTC3621I is guaranteed over the –40°C to 125°C operating junction

temperature range, and the LTC3621H is guaranteed over the –40°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 impedance and other environmental factors.

Note 4: The quiescent current in forced continuous mode does not include

switching loss of the power FETs.

Note 5: The LTC3621 is tested in a proprietary test mode that connects VFB

to the output of error amplifier.

Note 6: TJ is calculated from the ambient, TA, and power dissipation, PD,

according to the following formula:

TJ = TA + (PD • θJA)

Note 7: This IC includes overtemperature protection that is intended

to protect the device during momentary overload conditions. Junction

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

Continuous operation above the specified maximum operating junction

temperature may impair device reliability.