LTC3803-3
3
38033fd
ELECTRICAL CHARACTERISTICS The l denotes the specications which apply over the full operating
junction temperature range, otherwise specications are at TA = 25°C. VCC = 8V, unless otherwise noted. (Notes 2, 3)
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
VCLAMP25mA
VCC Shunt Regulator Voltage
ICC = 25mA, VITH/RUN = 0V
LTC3803E-3, LTC3803I-3
LTC3803H-3
LTC3803MP-3
l
8.4
8.1
9.5
10.5
10.7
V
VMARGIN
VCLAMP1mA – VTURNON Margin
LTC3803E-3, LTC3803I-3,
LTC3803H-3
LTC3803MP-3
l
0.05
0.03
0.6
V
ICC
Input DC Supply Current
Normal Operation
Start-Up
(Note 4)
VITH/RUN = 1.3V
VCC = VTURNON – 100mV
240
40
350
90
μA
VITHSHDN
Shutdown Threshold (at ITH/RUN)
VCC > VTURNON, VITH/RUN Falling
LTC3803E-3
LTC3803I-3, LTC3803H-3
LTC3803MP-3
l
0.15
0.10
0.09
0.28
0.45
V
IITHSTART
Start-Up Current Source
VITH/RUN = 0V
0.2
0.3
0.4
μA
VFB
Regulated Feedback Voltage
(Note 5)
0°C ≤ TJ ≤ 85°C
LTC3803E-3: –40°C ≤ TJ ≤ 85°C
LTC3803I-3: –40°C ≤ TJ ≤ 125°C
LTC3803H-3: –40°C ≤ TJ ≤ 150°C
LTC3803MP-3: –55°C ≤ TJ ≤ 150°C
l
0.788
0.780
0.800
0.812
0.820
V
VIMAX
Peak Current Sense Voltage
RSL = 0 (Note 6)
LTC3803E-3
LTC3803I-3, LTC3803H-3
LTC3803MP-3
l
90
85
100
115
120
mV
gm
Error Amplier Transconductance
ITH/RUN Pin Load = ±5μA (Note 5)
200
333
500
μA/V
ΔVO(LINE)
Output Voltage Line Regulation
(Note 5)
0.05
mV/V
IFB
VFB Input Current
(Note 5)
10
50
nA
fOSC
Oscillator Frequency
VITH/RUN = 1.3V
270
300
330
kHz
DCON(MIN)
Minimum Switch On Duty Cycle
VITH/RUN = 1.3V, VFB = 0.8V
8
9.6
%
DCON(MAX)
Maximum Switch On Duty Cycle
VITH/RUN = 1.3V, VFB = 0.8V
70
80
90
%
tRISE
Gate Drive Rise Time
CLOAD = 3000pF
40
ns
tFALL
Gate Drive Fall Time
CLOAD = 3000pF (Note 7)
40
ns
ISLMAX
Peak Slope Compensation Output Current (Note 7)
5
μA
tSFST
Soft-Start Time
1.4
ms
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 LTC3803-3 is tested under pulsed load conditions such
that TJ ≈ TA. The LTC3803E-3 is guaranteed to meet specications
from 0°C to 85°C junction temperature. Specications over the –40°C
to 125°C operating junction temperature range are assured by design,
characterization and correlation with statistical process controls. The
LTC3803I-3 is guaranteed over the –40°C to 125°C operating junction
temperature range, the LTC3803H-3 is guaranteed over the –40°C to
150°C operating junction temperature range and the LTC3803MP-3 is
tested and guaranteed over the full –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 specications is determined by specic operating conditions in
conjunction with board layout, the rated package thermal impedance and
other environmental factors.
Note 3: Junction temperature TJ is calculated from the ambient
temperature TA and power dissipation PD according to the following
formula:
TJ = TA + (PD 230°C/W).
Note 4: Dynamic supply current is higher due to the gate charge being
delivered at the switching frequency.
Note 5: The LTC3803-3 is tested in a feedback loop that servos VFB to the
output of the error amplier while maintaining ITH/RUN at the midpoint of
the current limit range.
Note 6: Peak current sense voltage is reduced dependent on duty cycle
and an optional external resistor in series with the SENSE pin (RSL). For
details, refer to the programmable slope compensation feature in the
Applications Information section.
Note 7: Guaranteed by design.