LTC3703_15 Datasheet, PDF (4/34 Pages) Linear Technology – 100V Synchronous Switching Regulator Controller

LTC3703
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
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 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.
Typical Performance Characteristics T_A = 25°C unless otherwise noted.
Efficiency vs Input Voltage
100
95
I_OUT = 5A
90
I_OUT = 0.5A
85
80
75 VOUT = 12V
f = 300kHz
PULSE SKIP DISABLED
70
0 10 20 30 40 50 60
INPUT VOLTAGE (V)
70 80
3703 G01
V_CC Current vs V_CC Voltage
3.5
3.0
COMP = 1.5V
2.5
2.0
V_FB = 0V
1.5
1.0
0.5
0
6
8
10
12
14
16
V_CC VOLTAGE (V)
3703 G04
4
Efficiency vs Load Current
100
Load Transient Response
95
V_IN = 15V
V_OUT
50mV/DIV
90
V_IN = 45V
85
V_IN = 75V
I_OUT
2A/DIV
80
75
V_OUT = 5V
f = 250kHz
PULSE SKIP ENABLED
70
0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
LOAD CURRENT (A)
3703 G02
V_IN = 50V
50µs/DIV
V_OUT = 12V
1A TO 5A LOAD STEP
3703 G03
V_CC Current vs Temperature
4
3
COMP = 1.5V
2
V_FB = 0V
1
0
–50 –25
0 25 50 75 100 125 150
TEMPERATURE (°C)
3703 G05
V_CC Shutdown Current vs
V_CC Voltage
100
90
80
70
60
50
40
30
20
10
0
6
8
10
12
14
16
V_CC VOLTAGE (V)
3703 G06
3703fc