LT3050 Series
1
3050fa
TYPICAL APPLICATION
DESCRIPTION
100mA, Linear Regulator
with Precision Current Limit
and Diagnostic Outputs
The LT
®
3050 series are micro-power, low noise, low
dropout voltage (LDO) linear regulators. The devices
supply 100mA of output current with a dropout voltage of
340mV. A 10nF bypass capacitor reduces output noise to
30V
RMS
in a 10Hz to 100kHz bandwidth and soft-starts
the reference. The LT3050’s ±45V input voltage rating
combined with its precision current limit and diagnostic
functions make the IC an ideal choice for robust, high
reliability applications.
A single resistor programs the LT3050’s current limit, accurate
to ±5% over a wide input voltage and temperature range.
A single resistor programs the LT3050’s minimum output
current monitor, useful for detecting open-circuit conditions.
The current monitor function sources a current equal to
1/100th of output current. A logic FAULT pin asserts low if
the LT3050 is in current limit, operating below its minimum
output current (open-circuit) or is in thermal shutdown.
The LT3050 optimizes stability and transient response
with low ESR ceramic capacitors, requiring a minimum of
2.2F. The LT3050 is available in fi xed output voltages of
3.3V and 5V, and as an adjustable version with an output
voltage range down to the 0.6V reference.The LT3050 is
available in the thermally-enhanced 12-Lead 3mm × 2mm
DFN and MSOP packages.
5V Supply with 100mA Precision Current Limit, 10mA I
MIN
FEATURES
APPLICATIONS
n
Output Current Monitor: 1/100
th
of I
OUT
n
Fault Indicator: Current Limit, Minimum I
OUT
or
Thermal Limit
n
Output Current: 100mA
n
Dropout Voltage: 340mV
n
Input Voltage Range: 1.6V to 45V
n
Programmable Precision Current Limit: ±5%
n
Programmable Minimum I
OUT
Monitor
n
Low Noise: 30μV
RMS
(10Hz to 100kHz)
n
Adjustable Output (V
REF
= V
OUT(MIN)
= 0.6V)
n
Fixed Output Voltages: 3.3V, 5V
n
Output Tolerance: ±2% Over Line, Load and Temperature
n
Stable with Low ESR, Ceramic Output Capacitors
(2.2F minimum)
n
Shutdown Current: <1A
n
Reverse-Battery, Reverse-Output and
Reverse-Current Protection
n
Thermal Limit Protection
n
12-Lead 3mm × 2mm DFN and MSOP Packages
n
Protected Antenna Supplies
n
Automotive Telematics
n
Industrial Applications (Trucks, Forklifts, etc.)
n
High Reliability Applications
External Current Limit R
IMAX
= 1.15k
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.
1µF
12V
V
IN
IN
I
MON
I
MAX
I
MIN
FAULT
SHDN
GND
OUT
REF/BYP
LT3050-5
5V
2.2µF
0.1µF
10nF
3k
(ADC FULL SCALE = 3V)
TO µP ADC
0.1µF
11.3k
(THRESHOLD = 10mA)
10nF
1.15k
(THRESHOLD = 100mA)
120k
3050 TA01
TEMPERATURE (°C)
CURRENT LIMIT FAULT THRESHOLD (mA)
105
100
101
102
103
104
98
99
3050 TA01a
95
96
97
–75 –50 –25 0 –25 50 75 100 125 150 175
V
IN
= 5.6V
V
IN
= 12V
V
IN
= 15V
V
OUT
= 5V
