LTC3025-1/LTC3025-2/
LTC3025-3/LTC3025-4
500mA Micropower
VLDO Linear Regulators
Features
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Description
Wide Input Voltage Range: 0.9V to 5.5V
Stable with Ceramic Capacitors
Very Low Dropout: 85mV at 500mA
Adjustable Output Range: 0.4V to 3.6V (LTC3025-1)
Fixed Output: 1.2V (LTC3025-2), 1.5V (LTC3025-3),
1.8V (LTC3025-4)
±2% Voltage Accuracy over Temperature,
Supply and 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 LTC®3025-X is a micropower, VLDO™ (very low dropout) linear regulator which operates from input voltages as
low as 0.9V. The device is capable of supplying 500mA of
output current with a typical dropout voltage of only 85mV.
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 LTC3025-1
features an adjustable output with a low 0.4V reference
while the LTC3025-2, LTC3025-3, and LTC3025-4 have
fixed 1.2V, 1.5V and 1.8V output voltages respectively.
The LTC3025-X’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
,
thermal overload protection and output current limiting.
The LTC3025-X 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. Protected by U.S. Patents including 7224204, 7218082.
Typical Application
1MHz VIN Supply Rejection
1.2V Output Voltage from 1.5V Input Supply
50
45
BIAS
1.5V HIGH
EFFICIENCY 1.5V
DC/DC
BUCK
0.1µF
1µF
LTC3025-2
IN
SENSE
0.1µF
OFF ON
SHDN
VOUT = 1.2V
IOUT ≤ 500mA
GND
30251234 TA01
COUT = 10µF
40
REJECTION (dB)
Li-Ion
OR
3-CELL
NiMH
OUT
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
30251234 TA01b
30251234ff
1
