LTC3785-1 Datasheet, PDF (3/20 Pages) Linear Technology – 10V, High Effi ciency, Buck-Boost Controller with Power Good

LTC3785-1
ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T_A = 25°C. V_IN = V_OUT = V_DRV = V_BST1 = V_BST2 = 3.6V, R_T = 49.9k, R_ILSET = 59k.
PARAMETER
V_CC Regulator Sink Current
Run/Soft-Start
RUN/SS Threshold
RUN/SS Input Current
RUN/SS Discharge Current
Current Limit
Current Limit Sense Threshold
Reverse Current Limit Sense Threshold
Input Current
CCM Input Threshold (High)
CCM Input Threshold (Low)
CCM Input Current
Burst Mode Operation
Mode Threshold
Mode Input Current
t_ON Time
Oscillator
Frequency Accuracy
Switching Characteristics
Maximum Duty Cycle
TG1, TG2 Driver Impedance
BG1, BG2 Driver Impedance
TG1, TG2 Rise Time
BG1, BG2 Rise Time
TG1, TG2 Fall Time
BG1, BG2 Fall Time
Buck Driver Nonoverlap Time
Boost Driver Nonoverlap Time
Power Good
Undervoltage Threshold
Undervoltage Hysteresis
Overvoltage Threshold
Overvoltage Hysteresis
PGOOD Output Low
PGOOD Leakage
V_SENSE Input Current
CONDITIONS
V_OUT = V_CC = 5V
When IC is Enabled
When EA is at Maximum Boost Duty Cycle
RUN/SS = 0V
During Current Limit
I_SVIN to I_SSW1, R_ILSET = 121k
I_SVIN to I_SSW1, R_ILSET = 59k
I_SSW2 to I_SVOUT, CCM > 2V
I_SSW2 to I_SVOUT, CCM < 0.4V
I_SVIN
I_SVOUT
I_SSW1, I_SSW2
Boost (% Switch BG2 On)
Buck (% Switch TG1 On)
C_LOAD = 3300pF (Note 3)
C_LOAD = 3300pF (Note 3)
C_LOAD = 3300pF (Note 3)
C_LOAD = 3300pF (Note 3)
TG1 to BG1
TG2 to BG2
V_SENSE Falling, % Below FB Regulation Voltage
V_SENSE Rising % Above FB Regulation Voltage,
MODE = 0V
I_PGOOD = 500μA
V_PGOOD = 5.5V
V_SENSE = Measured FB Voltage
MIN
l 0.35
l 20
l 55
l –50
l
l 2.2
l
l 0.8
l 370
l 80
–5
5
TYP MAX
800
0.7
1.1
1.9
–1
1
5
60
100
105
155
–110 –170
–15
–35
80
150
10
20
0.1
5
0.4
0.01
1
1.5
2.2
0.01
1
1.4
509
650
90
99
2
2
20
20
20
20
100
100
–7.5 –10.5
1.5
7.5
10.5
–2
200
500
5
1
500
UNITS
μA
V
V
μA
μA
mV
mV
mV
mV
μA
μA
μA
V
V
μA
V
μA
μs
kHz
%
%
Ω
Ω
ns
ns
ns
ns
ns
ns
%
%
%
%
mV
μA
nA
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 LTC3785E-1 is guaranteed to meet performance specifications
from 0°C to 85°C. Specifications over –40°C to 85°C operating
temperature range are assured by design, characterization and correlation
with statistical process controls.
Note 3: Specification is guaranteed by design and not 100% tested in production.
Note 4: Current measurements are performed when the outputs are not switching.
Note 5: The IC is tested in a feedback loop to make the measurement.
37851f
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