Datasheet

LTC3703
4
3703fc
Typical perForMance characTerisTics
Efficiency vs Input Voltage Efficiency vs Load Current Load Transient Response
V
CC
Current vs V
CC
Voltage V
CC
Current vs Temperature
V
CC
Shutdown Current vs
V
CC
Voltage
elecTrical characTerisTics
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 LTC3703E is guaranteed to meet performance specifications from
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 LTC3703I is guaranteed over the full –40°C to 125°C
operating junction temperature range. The LTC3703H is guaranteed over the
full –40°C to 150°C operating junction temperature range.
Note 3: T
J
is calculated from the ambient temperature T
A
and power
dissipation P
D
according to the following formula:
LTC3703: T
J
= T
A
+ (P
D
• 100 °C/W) G Package
Note 4: The LTC3703 is tested in a feedback loop that servos V
FB
to the
reference voltage with the COMP pin forced to a voltage between 1V and 2V.
Note 5: The dynamic input supply current is higher due to the power
MOSFET gate charge being
delivered at the switching frequency (Q
G
f
OSC
).
Note 6: Guaranteed by design. Not subject to test.
Note 7: This IC includes overtemperature protection that is intended
to protect the device during momentary overload conditions. Junction
temperature will exceed 125°C when overtemperature protection is active.
Continuous operation above the specified maximum operating junction
temperature may impair device reliability.
Note 8: R
DS(ON)
guaranteed by correlation to wafer level measurement.
Note 9: High junction temperatures degrade operating lifetimes. Operating
lifetime at junction temperatures greater than 125°C is derated to 1000 hours.
Note 10: Transient voltages (such as due to inductive ringing) are allowed
beyond this range provided that the voltage does not exceed 10V below
ground and duration does not exceed 20ns per switching cycle.
T
A
= 25°C unless otherwise noted.
INPUT VOLTAGE (V)
EFFICIENCY (%)
3703 G01
100
95
90
85
80
75
70
0
20
40
50
10 30
60
70
80
V
OUT
= 12V
f = 300kHz
PULSE SKIP DISABLED
I
OUT
= 0.5A
I
OUT
= 5A
LOAD CURRENT (A)
0 0.5 1.5 2.5 3.5 4.5
EFFICIENCY (%)
100
95
90
85
80
75
70
1.0 2.0 3.0 4.0
3703 G02
5.0
V
OUT
= 5V
f = 250kHz
PULSE SKIP ENABLED
V
IN
= 75V
V
IN
= 45V
V
IN
= 15V
3703 G03
V
OUT
50mV/DIV
I
OUT
2A/DIV
V
IN
= 50V
V
OUT
= 12V
1A TO 5A LOAD STEP
50µs/DIV
V
CC
VOLTAGE (V)
6
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
12
3703 G04
8 10 14 16
V
CC
CURRENT (mA)
V
FB
= 0V
COMP = 1.5V
3703 G05
TEMPERATURE (°C)
–50 –25 0 25
V
CC
CURRENT (mA)
100
150
50 75 125
4
3
2
1
0
V
FB
= 0V
COMP = 1.5V
V
CC
VOLTAGE (V)
6
V
CC
CURRENT (µA)
100
90
80
70
60
50
40
30
20
10
0
14
3703 G06
8
10
12
16