LT3085

3

3085fb

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.

The LT3085 is tested and specified under pulse load conditions such that

LT3085E over the full –40°C to 125°C operating junction temperature

range is assured by design, characterization, and correlation with

statistical process controls. The LT3085I regulators are guaranteed

over the full –40°C to 125°C operating junction temperature range. The

LT3085 (MP grade) is 100% tested and guaranteed over the –55°C to

125°C operating junction temperature range.

Note 3. Minimum load current is equivalent to the quiescent current of

the part. Since all quiescent and drive current is delivered to the output

of the part, the minimum load current is the minimum current required to

maintain regulation.

Note 4. For the LT3085, dropout is caused by either minimum control

specified with respect to the output voltage. The specifications represent

the minimum input-to-output differential voltage required to maintain

regulation.

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

SET Pin Current

l

9.9

9.8

10

10

10.1

10.2

μA

μA

l

–1.5

–3

1.5

3

mV

mV

Load Regulation

l

–0.1

–0.6

–1

nA

mV

Line Regulation

0.1

0.003

0.5

nA/V

mV/V

Minimum Load Current (Notes 3, 9)

l

l

300

500

1

μA

mA

l

1.2

1.35

1.6

V

V

l

l

85

275

150

450

mV

mV

l

l

3

8

6

15

mA

mA

Current Limit (Note 9)

l

500

650

mA

Error Amplifier RMS Output Noise (Note 6)

33

Reference Current RMS Output Noise (Note 6) 10Hz ≤ f≤ 100kHz

0.7

Ripple Rejection

f=10kHz

f=1MHz

90

75

20

dB

dB

dB

10ms Pulse

0.003

%/W

The

output transistor. This current will track output current with roughly a 1:60

ratio. The minimum value is equal to the quiescent current of the device.

Note 6. Output noise is lowered by adding a small capacitor across the

voltage setting resistor. Adding this capacitor bypasses the voltage setting

resistor shot noise and reference current noise; output noise is then equal

to error amplifier noise (see Applications Information section).

Note 7. The SET pin is clamped to the output with diodes through 1k

resistors. These resistors and diodes will only carry current under

transient overloads.

Note 8. Load regulation is Kelvin sensed at the package.

Note 9. Current limit includes foldback protection circuitry. Current limit

decreases at higher input-to-output differential voltages. See the Typical

Performance Characteristics graphs for more information.

Note 10. This IC includes over-temperature protection that is intended

to protect the device during momentary overload conditions. Junction

temperature will exceed the maximum operating junction temperature

when over-temperature protection is active. Continuous operation above

the specified maximum operating junction temperature may impair device

reliability.