LTC3785-1 Linear Technology, LTC3785-1 Datasheet - Page 3

• Manufacturer Part Number: LTC3785-1
• Description: Buck-Boost Controller
• Manufacturer: Linear Technology

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ELECTRICAL CHARACTERISTICS
temperature range, otherwise specifi cations are at T
PARAMETER
V
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
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
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 specifi cations
from 0°C to 85°C. Specifi cations over –40°C to 85°C operating
ON
CC
SENSE
Time
Regulator Sink Current
Input Current
CONDITIONS
V
When IC is Enabled
When EA is at Maximum Boost Duty Cycle
RUN/SS = 0V
During Current Limit
I
I
I
I
I
I
I
Boost (% Switch BG2 On)
Buck (% Switch TG1 On)
C
C
C
C
TG1 to BG1
TG2 to BG2
V
V
MODE = 0V
I
V
V
SVIN
SVIN
SSW2
SSW2
SVIN
SVOUT
SSW1
PGOOD
OUT
LOAD
LOAD
LOAD
LOAD
SENSE
SENSE
PGOOD
SENSE
A
to I
to I
= V
, I
to I
to I
= 3300pF (Note 3)
= 3300pF (Note 3)
= 3300pF (Note 3)
= 3300pF (Note 3)
= 25°C. V
= 500μA
SSW2
Falling, % Below FB Regulation Voltage
Rising % Above FB Regulation Voltage,
= Measured FB Voltage
= 5.5V
SSW1
SSW1
CC
SVOUT
SVOUT
= 5V
The
, R
, R
, CCM > 2V
, CCM < 0.4V
ILSET
ILSET
l
IN
denotes the specifi cations which apply over the full operating
= V
= 121k
= 59k
OUT
temperature range are assured by design, characterization and correlation
with statistical process controls.
Note 3: Specifi cation 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.
= V
DRV
= V
BST1
= V
BST2
l
l
l
l
l
l
l
l
l
l
= 3.6V, R
MIN
0.35
–50
370
2.2
0.8
20
55
80
–5
5
T
= 49.9k, R
–110
LTC3785-1
0.01
0.01
–7.5
TYP
800
105
–15
509
100
100
200
0.7
1.9
0.1
1.5
1.4
1.5
7.5
–1
60
80
10
90
99
20
20
20
20
–2
1
2
2
1
ILSET
–10.5
MAX
–170
10.5
100
155
–35
150
650
500
500
1.1
0.4
2.2
20
5
5
1
1
5
= 59k.
UNITS
37851f
3
kHz
mV
mV
mV
mV
mV
μA
μA
μA
μA
μA
μA
μA
μA
μA
nA
μs
ns
ns
ns
ns
ns
ns
%
%
%
%
%
%
Ω
Ω
V
V
V
V
V