Datasheet

LM3103
SNVS523F –SEPTEMBER 2007–REVISED APRIL 2013 www.ti.com
Electrical Characteristics
Specifications with standard type are for T
J
= 25°C only; limits in boldface type apply over the full Operating Junction
Temperature (T
J
) range. Minimum and Maximum limits are specified through test, design, or statistical correlation. Typical
values represent the most likely parametric norm at T
J
= 25°C, and are provided for reference purposes only. Unless
otherwise stated the following conditions apply: V
IN
= 18V, V
OUT
= 3.3V.
Symbol Parameter Conditions Min Typ Max Units
Start-Up Regulator, V
CC
V
CC
V
CC
output voltage C
VCC
= 1 µF, no load 5.6 6.0 6.2 V
V
IN
- V
CC
V
IN
- V
CC
dropout voltage
(1)
I
CC
= 2mA 55 150 mV
I
CC
= 10mA 235 500
V
CC-UVLO
V
CC
under-voltage lockout threshold V
IN
increasing 3.5 3.7 4.1 V
(UVLO)
V
CC-UVLO-HYS
V
CC
UVLO hysteresis V
IN
decreasing 275 mV
I
IN
I
IN
operating current No switching, V
FB
= 1V 1.0 1.25 mA
I
IN-SD
I
IN
operating current, Device shutdown V
EN
= 0V 20 40 µA
I
VCC
V
CC
current limit V
CC
= 0V 20 33 42 mA
Switching Characteristics
R
DS-UP-ON
Main MOSFET R
DS(on)
0.370 0.7 Ω
R
DS- DN-ON
Syn. MOSFET R
DS(on)
0.220 0.4 Ω
Soft-start
I
SS
SS pin source current V
SS
= 0V 45 70 95 µA
Current Limit
I
CL
Syn. MOSFET current limit threshold 0.9 A
ON/OFF Timer
t
on
ON timer pulse width V
IN
= 10V, R
ON
= 33 kΩ 0.350 µs
V
IN
= 18V, R
ON
= 33 kΩ 0.170
t
on-MIN
ON timer minimum pulse width 100 ns
t
off
OFF timer pulse width 240 ns
Enable Input
V
EN
EN Pin input threshold V
EN
rising 1.6 1.85 V
V
EN-HYS
Enable threshold hysteresis V
EN
falling 230 mV
I
EN
Enable Pull-up Current V
EN
= 0V 1 µA
Regulation and Over-Voltage Comparator
V
FB
In-regulation feedback voltage T
J
= −40°C to +125°C 0.588 0.6 0.612 V
V
FB-OV
Feedback over-voltage threshold 0.655 0.680 0.705 V
I
FB
1 nA
Thermal Shutdown
T
SD
Thermal shutdown temperature T
J
rising 165 °C
T
SD-HYS
Thermal shutdown temperature T
J
falling 20 °C
hysteresis
(1) V
CC
provides self bias for the internal gate drive and control circuits. Device thermal limitations limit external loading.
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