Datasheet
LTC3412
3
3412fb
TYPICAL PERFOR A CE CHARACTERISTICS
UW
Efficiency vs Load CurrentEfficiency vs Load Current Efficiency vs Load Current
LOAD CURRENT (A)
0.001
EFFICIENCY (%)
100
80
60
40
20
0
10
3412 G01
V
IN
= 3.3V
V
OUT
= 2.5V
Burst Mode OPERATION
FORCED CONTINUOUS
0.1 10.01
100
90
80
70
60
50
40
30
20
10
0
LOAD CURRENT (A)
0.001
EFFICIENCY (%)
10
3412 G02
V
OUT
= 2.5V
1MHz
Burst Mode OPERATION
0.1 10.01
V
IN
= 3.3V V
IN
= 5V
LOAD CURRENT (A)
0.001
EFFICIENCY (%)
100
90
80
70
60
50
40
30
20
10
0
10
3412 G03
V
OUT
= 2.5V
1MHz
FORCED CONTINUOUS
0.1 10.01
V
IN
= 3.3V V
IN
= 5V
ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 3.3V unless otherwise specified.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
f
OSC
Switching Frequency R
OSC
= 309kΩ 0.88 0.95 1.1 MHz
Switching Frequency Range (Note 6) 0.3 4 MHz
f
SYNC
SYNC Capture Range (Note 6) 0.3 4 MHz
R
PFET
R
DS(ON)
of P-Channel FET I
SW
= 1A (Note 7) 85 110 mΩ
R
NFET
R
DS(ON)
of N-Channel FET I
SW
= –1A (Note 7) 65 90 mΩ
I
LIMIT
Peak Current Limit 4 5.4 A
V
UVLO
Undervoltage Lockout Threshold 2.375 2.500 2.625 V
I
LSW
SW Leakage Current V
RUN
= 0V, V
IN
= 5.5V 0.1 1 μA
V
RUN
RUN Threshold 0.5 0.65 0.8 V
I
RUN
RUN/SS Leakage Current 1 μA
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 LTC3412E 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 LTC3412I is guaranteed to meet
specified performance over the –40°C to 85°C temperature range.
Note 3: The LTC3412 is tested in a feedback loop that adjusts V
FB
to
achieve a specified error amplifier output voltage (I
TH
).
Note 4: Dynamic supply current is higher due to the internal gate charge
being delivered at the switching frequency.
Note 5: T
J
is calculated from the ambient temperature T
A
and power
dissipation as follows: LTC3412: T
J
= T
A
+ P
D
(37.6°C/W).
Note 6: 4MHz operation is guaranteed by design and not production tested.
Note 7: Switch on resistance is guaranteed by design and test correlation
in the UF package and by production test in the FE package.