LTC3873-5
3
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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 LTC3873E-5 is guaranteed to meet performance specications
from 0°C to 85°C. Specications over the –40°C to 85°C operating
temperature range are assured by design, characterization and correlation
with statistical process controls. The LTC3873I-5 is guaranteed to meet
performance specications over the full –40°C to 125°C operating
temperature range.
Note 3: TJ is calculated from the ambient temperature TA and power
dissipation PD according to the following formula:
TJ = TA + (PD θJA)
Note 4: The dynamic input supply current is higher due to power MOSFET
gate charging (QG fOSC). See Applications Information.
Note 5: The LTC3873-5 is tested in a feedback loop which servos VFB to
the reference voltage with the ITH pin forced to the midpoint of its voltage
range (0.7V ≤ VITH ≤ 1.9V, midpoint = 1.3V).
Note 6: Rise and fall times are measured at 10% and 90% levels.
VCC = 5.6V.
ELECTRICAL CHARACTERISTICS The l denotes the specications which apply over the full operating
temperature range, otherwise specications are at TA = 25°C. VCC = 5V unless otherwise noted. (Note 2)
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
Input DC Supply Current
Normal Operation
Shutdown
UVLO
Typicals at VCC = 5V (Note 4)
VITH = 1.9V
VRUN/SS = 0V
VCC = UVLO Threshold – 100mV, VRUN/SS = VCC
300
50
35
400
80
50
μA
Undervoltage Lockout Threshold
VCC Rising
VCC Falling
VCC Hysteresis
l
3.8
2.5
0.9
4.1
2.9
1.25
4.4
3.3
1.7
V
Shutdown Threshold (at RUN/SS)
VRUN/SS Falling
VRUN/SS Rising
l
0.5
0.6
0.7
0.8
0.9
1.0
V
Regulated Feedback Voltage
(Note 5)
l
1.182
1.2
1.218
V
Feedback Voltage Line Regulation
3.5V < VCC < 9V (Note 5)
0.1
mV/V
Feedback Voltage Load Regulation
VITH = 1.6V (Note 5)
VITH = 1V (Note 5)
0.05
–0.05
%
VFB Input Current
(Note 5)
25
50
nA
RUN/SS Pull Up Current
VRUN/SS = 0V
VRUN/SS = 1.3V
1.5
5
3
15
4.5
25
μA
Maximum Duty Cycle
70
78
84
%
ISLMAX, Peak Slope Compensation Current
20
μA
Oscillator Frequency
160
200
240
kHz
Gate Drive Rise Time
CLOAD = 3000pF (Note 6)
40
ns
Gate Drive Fall Time
CLOAD = 3000pF (Note 6)
40
ns
Peak Current Sense Voltage
IPRG = GND
IPRG = Float
IPRG = VIN
l
95
165
265
110
185
295
125
210
325
mV
VIN Shunt Regulator Voltage
IIN = 1mA, IIN = 25mA, VRUN/SS = 0V
l
9
9.3
9.6
V
Default Internal Soft-Start
3.3
ms