LTC3873-5 Datasheet, PDF (3/16 Pages) Linear Technology – No RSENSETM Constant Frequency Current Mode Boost/Flyback/SEPIC DC/DC Controller

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