LTC3412
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
f
OSC
f
SYNC
R
PFET
R
NFET
I
LIMIT
V
UVLO
I
LSW
V
RUN
I
RUN
PARAMETER
Switching Frequency
Switching Frequency Range
SYNC Capture Range
R
DS(ON)
of P-Channel FET
R
DS(ON)
of N-Channel FET
Peak Current Limit
Undervoltage Lockout Threshold
SW Leakage Current
RUN Threshold
RUN/SS Leakage Current
CONDITIONS
R
OSC
= 309kΩ
(Note 6)
(Note 6)
I
SW
= 1A (Note 7)
I
SW
= –1A (Note 7)
MIN
0.88
0.3
0.3
TYP
0.95
MAX
1.1
4
4
110
90
2.625
1
0.8
1
UNITS
MHz
MHz
MHz
mΩ
mΩ
A
V
μA
V
μA
ELECTRICAL CHARACTERISTICS
4
2.375
V
RUN
= 0V, V
IN
= 5.5V
0.5
85
65
5.4
2.500
0.1
0.65
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.
TYPICAL PERFOR A CE CHARACTERISTICS
Efficiency vs Load Current
100
100
90
80
Burst Mode OPERATION
80
EFFICIENCY (%)
EFFICIENCY (%)
60
FORCED CONTINUOUS
40
60
50
40
30
EFFICIENCY (%)
20
V
IN
= 3.3V
V
OUT
= 2.5V
0.01
0.1
1
LOAD CURRENT (A)
10
3412 G01
0
0.001
U W
Efficiency vs Load Current
100
90
V
IN
= 3.3V
V
IN
= 5V
80
70
60
50
40
30
V
OUT
= 2.5V
1MHz
Burst Mode OPERATION
0.01
0.1
1
LOAD CURRENT (A)
10
3412 G02
Efficiency vs Load Current
70
V
IN
= 3.3V
V
IN
= 5V
20
10
20
10
0
0.001
0
0.001
V
OUT
= 2.5V
1MHz
FORCED CONTINUOUS
0.01
0.1
1
LOAD CURRENT (A)
10
3412 G03
3412fb
3
LINER [ LINEAR TECHNOLOGY ]
