LT3050
100mA, Low Noise
Linear Regulator With Precision Current
Limit And Diagnostic Functions
DESCRIPTION
FEATURES
The LT®3050 is a micro-power, low noise, low dropout
voltage(LDO)linearregulator. Thedevicesupplies100mA
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Output Current: 100mA
Dropout Voltage: 340mV
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Input Voltage Range: 1.6V to 45V
of output current with a dropout voltage of 340mV. A 10nF
bypass capacitor reduces output noise to 30μV in a
10Hz to 100kHz bandwidth and soft-starts the reference.
The LT3050’s 45V input voltage rating combined with its
precisioncurrentlimitanddiagnosticfunctionsmaketheIC
an ideal choice for robust, high reliability applications.
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Programmable Precision Current Limit: 5ꢀ
RMS
Programmable Minimum I
Monitor
OUT
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Output Current Monitor: 1/100 of I
OUT
Fault Indicator: Current Limit, Minimum I
or
OUT
Thermal Limit
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Low Noise: 30μV
(10Hz to 100kHz)
RMS
AsingleresistorprogramstheLT3050’scurrentlimit,accurate
to 5ꢀ over a wide input voltage and temperature range.
A single resistor programs the LT3050’s minimum output
currentmonitor,usefulfordetectingopen-circuitconditions.
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.
Adjustable Output (V = V
= 0.6V)
REF
OUT(MIN)
Output Tolerance: 2ꢀ Over Line, Load and Temperature
Stable with Low ESR, Ceramic Output Capacitors
(2.2μF minimum)
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Shutdown Current: <1μA
Reverse-Battery, Reverse-Output and
Reverse-Current Protection
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Thermal Limit Protection
The LT3050 optimizes stability and transient response
with low ESR ceramic capacitors, requiring a minimum
of 2.2μF. The LT3050 is available as an adjustable device
with an output voltage range down to the 0.6V reference.
TheLT3050isavailableinthethermally-enhanced12-Lead
3mm × 2mm DFN and MSOP packages.
12-Lead 3mm × 2mm DFN and MSOP Packages
APPLICATIONS
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Protected Antenna Supplies
Automotive Telematics
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Industrial Applications (Trucks, Forklifts, etc.)
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
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High Reliability Applications
Technology Corporation. All other trademarks are the property of their respective owners.
External Current Limit
RIMAX = 1.15k
TYPICAL APPLICATION
105
5V Supply with 100mA Precision Current Limit, 10mA IMIN
V
= 5V
OUT
104
103
102
101
100
99
IN
OUT
5V
1ꢀ
442k
V
IN
= 15V
12V
IN
SHDN
2.2ꢁF
1ꢁF
120k
V
ADJ
FAULT
1ꢀ
60.4k
V
V
= 12V
IN
IN
LT3050
I
MAX
I
= 5.6V
TO ꢁP ADC
0.1ꢁF
MON
98
1.15k
10nF
3k
(THRESHOLD = 100mA)
97
(ADC FULL SCALE = 3V)
96
I
REF/BYP
MIN
11.3k
95
0.1ꢁF
GND
–75 –50 –25
0
–25 50 75 100 125 150 175
10nF
(THRESHOLD = 10mA)
TEMPERATURE (°C)
3050 TA01
3050 TA01a
3050f
1