LTC3780_12 Datasheet, PDF (9/28 Pages) Linear Technology – High Effi ciency, Synchronous, 4-Switch Buck-Boost Controller

LTC3780
TYPICAL PERFORMANCE CHARACTERISTICS T_A = 25°C, unless otherwise noted.
Load Step
Load Step
Load Step
V_OUT
500mV/DIV
V_OUT
500mV/DIV
V_OUT
500mV/DIV
I_L
5A/DIV
I_L
5A/DIV
I_L
5A/DIV
V_IN = 18V
200μs/DIV
V_OUT = 12V
LOAD STEP: 0A TO 5A
CONTINUOUS MODE
3780 G27
Line Transient
V_IN = 12V
200μs/DIV
V_OUT = 12V
LOAD STEP: 0A TO 5A
CONTINUOUS MODE
3780 G28
V_IN = 6V
200μs/DIV
V_OUT = 12V
LOAD STEP: 0A TO 5A
CONTINUOUS MODE
Line Transient
V_IN
10V/DIV
V_OUT
500mV/DIV
V_IN
10V/DIV
V_OUT
500mV/DIV
I_L
1A/DIV
V_OUT = 12V
500μs/DIV
I_LOAD = 1A
V_IN STEP: 7V TO 20V
CONTINUOUS MODE
3780 G30
I_L
1A/DIV
V_OUT = 12V
500μs/DIV
I_LOAD = 1A
V_IN STEP: 20V TO 7V
CONTINUOUS MODE
3780 G31
3780 G29
PIN FUNCTIONS (SSOP/QFN)
PGOOD (Pin 1/Pin 30): Open-Drain Logic Output. PGOOD
is pulled to ground when the output voltage is not within
±7.5% of the regulation point.
SS (Pin 2/Pin 31): Soft-start reduces the input power
sources’ surge currents by gradually increasing the
controller’s current limit. A minimum value of 6.8nF is
recommended on this pin.
SENSE⁺ (Pin 3/Pin 1): The (+) Input to the Current Sense
and Reverse Current Detect Comparators. The I_TH pin
voltage and built-in offsets between SENSE^– and SENSE⁺
pins, in conjunction with R_SENSE, set the current trip
threshold.
SENSE^– (Pin 4/Pin 2): The (–) Input to the Current Sense
and Reverse Current Detect Comparators.
I_TH (Pin 5/Pin 3): Current Control Threshold and Error
Amplifier Compensation Point. The current comparator
threshold increases with this control voltage. The voltage
ranges from 0V to 2.4V.
3780fe
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