LTC3780
TYPICAL PERFORMANCE CHARACTERISTICS
Load Step
Load Step
T
A
= 25°C, unless otherwise noted.
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
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
3780 G29
Line Transient
V
IN
10V/DIV
Line Transient
V
IN
10V/DIV
V
OUT
500mV/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
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
9
LINEAR [ LINEAR INTEGRATED SYSTEMS ]
