LTC3646/LTC3646-1

4

36461fc

For more information www.linear.com/LTC3646

ELECTRICAL CHARACTERISTICS The

l

denotes the specifications which apply over the specified operating

junction temperature range, otherwise specifications are at TA = 25°C (Note 2), PVIN = SVIN = 12V unless otherwise noted.

SYMBOL

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

tPGOOD

PGOOD Filter Time

RT = INTVCC

15

30

µs

RPGOOD

PGOOD Pull-Down Resistance

IPGOOD = 10mA

63

Ω

PGOOD Leakage

VPGOOD = VINTVCC

1.0

µA

tSS

Internal Soft-Start Time

250

500

µs

VMODE/SYNC

Mode Threshold Voltage

SYNC Threshold Voltage

Mode VIH

Mode VIL

SYNCIH

SYNCIL

l

l

l

l

1.2

1.2

0.3

0.3

V

V

V

V

MODE/SYNC Input Current

1

2

µA

Internal ITH Voltage Threshold

l

INTVCC – 0.3V

V

VON Pin Input Impedance

LTC3646

LTC3646-1

520

600

kΩ

kΩ

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: The LTC3646 is tested under pulsed load conditions such that

TJ ≈ TA. The LTC3646E 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

LTC3646I is guaranteed over the –40°C to 125°C operating junction

temperature range and the LTC3646H is guaranteed over the –40°C to

150°C operating junction temperature range. High junction temperatures

derate 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 3: Dynamic supply current is higher due to gate charging being

delivered at the switch frequency.

Note 4: Limits to VOUT are a subject to PVIN, SVIN, tON(MIN), tOFF(MIN),

and frequency constraints. See the Applications Information section for a

further discussion. These items are tested with appropriate combinations

of VIN, VON and frequency.

Note 5: RDS(ON) is guaranteed by correlation to wafer level measurements.

Note 6: Maximum allowed current draw when used as a regulated output

is 5mA. This supply is only intended to provide additional DC load current

as needed and not to regulate large transient or AC behavior as such

waveforms may impact LTC3646 operation.

Note 7: This IC includes overtemperature protection intended to protect

the device during momentary overload conditions. The maximum junction

temperature may be exceeded when overtemperature protection is active.

Continuous operation above the specified maximum operating junction

temperature may result in device degradation or failure.