LTC3025
300mA Micropower
VLDO Linear Regulator
FEATURES
DESCRIPTION
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The LTC®3025 is a micropower, VLDOTM (very low dropout) linear regulator which operates from input voltages as
low as 0.9V. The device is capable of supplying 300mA of
output current with a typical dropout voltage of only 45mV.
A BIAS supply is required to run the internal reference and
LDO circuitry while output current comes directly from
the IN supply for high efficiency regulation. The low 0.4V
internal reference voltage allows the LTC3025 output to
be programmed to much lower voltages than available in
common LDOs (range of 0.4V to 3.6V). The output voltage
is programmed via two ultrasmall SMD resistors.
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Wide Input Voltage Range: 0.9V to 5.5V
Stable with Ceramic Capacitors
Very Low Dropout: 45mV at 300mA
Adjustable Output Range: 0.4V to 3.6V
±2% Voltage Accuracy over Temperature
Supply Load
Low Noise: 80μVRMS (10Hz to 100kHz)
BIAS Voltage Range: 2.5V to 5.5V
Fast Transient Recovery
Shutdown Disconnects Load from VIN and VBIAS
Low Operating Current: IIN = 4μA, IBIAS = 50μA Typ
Low Shutdown Current: IIN = 1μA, IBIAS = 0.01μA Typ
Output Current Limit
Thermal Overload Protection
Available in 6-Lead (2mm × 2mm) DFN Package
APPLICATIONS
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Low Power Handheld Devices
Low Voltage Logic Supplies
DSP Power Supplies
Cellular Phones
Portable Electronic Equipment
Handheld Medical Instruments
Post Regulator for Switching Supply Noise Rejection
The LTC3025’s low quiescent current makes it an ideal
choice for use in battery-powered systems. For 3-cell
NiMH and single cell Li-Ion applications, the BIAS voltage
can be supplied directly from the battery while the input
can come from a high efficiency buck regulator, providing
a high efficiency, low noise output.
Other features include high output voltage accuracy,
excellent transient response, stability with ultralow ESR
ceramic capacitors as small as 1μF short-circuit and
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thermal overload protection and output current limiting.
The LTC3025 is available in a tiny, low profile (0.75mm)
6-lead DFN (2mm × 2mm) package.
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and VLDO
and ThinSOT are trademarks of Linear Technology Corporation. All other trademarks are the
property of their respective owners.
TYPICAL APPLICATION
1.2V Output Voltage from 1.5V Input Supply
1MHz VIN Supply Rejection
50
Li-Ion
OR
3-CELL
NiMH
1.5V HIGH
EFFICIENCY 1.5V
DC/DC
BUCK
0.1μF
OUT
80.6k
LTC3025
IN
ADJ
0.1μF
OFF ON
40.2k
SHDN
GND
3025 TA01
1μF
VOUT = 1.2V
IOUT ≤ 300mA
45
COUT = 10μF
40
REJECTION (dB)
BIAS
35
COUT = 1μF
30
25
20
15
10
5 BIAS = 3.6V
VOUT = 1.2V
0
1.2 1.4 1.6
IOUT = 100mA
IOUT = 300mA
1.8 2.0
VIN (V)
2.2
2.4
2.6
3025 TA01b
3025fd
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