LTC3025_15 Datasheet, PDF (1/12 Pages) Linear Technology – 300mA Micropower VLDO Linear Regulator

LTC3025
300mA Micropower
VLDO Linear Regulator
FEATURES
n _{Wide Input Voltage Range: 0.9V to 5.5V}
n _{Stable with Ceramic Capacitors}
n _{Very Low Dropout: 45mV at 300mA}
n _{Adjustable Output Range: 0.4V to 3.6V}
n _{±2% Voltage Accuracy over Temperature}
Supply Load
n _{Low Noise: 80μVRMS (10Hz to 100kHz)}
n _{BIAS Voltage Range: 2.5V to 5.5V}
n _{Fast Transient Recovery}
n _{Shutdown Disconnects Load from VIN and VBIAS}
n _{Low Operating Current: IIN = 4μA, IBIAS = 50μA Typ}
n _{Low Shutdown Current: IIN = 1μA, IBIAS = 0.01μA Typ}
n _{Output Current Limit}
n _{Thermal Overload Protection}
n _{Available in 6-Lead (2mm × 2mm) DFN Package}
APPLICATIONS
n _{Low Power Handheld Devices}
n _{Low Voltage Logic Supplies}
n _{DSP Power Supplies}
n _{Cellular Phones}
n _{Portable Electronic Equipment}
n _{Handheld Medical Instruments}
n _{Post Regulator for Switching Supply Noise Rejection}
DESCRIPTION
The LTC^®3025 is a micropower, VLDO^TM (very low drop-
out) 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.
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
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
Li-Ion
OR
3-CELL
NiMH
1.5V HIGH
EFFICIENCY _1.5V
DC/DC
BUCK
0.1μF
0.1μF
OFF ON
BIAS
OUT
LTC3025
IN
ADJ
SHDN
GND
80.6k
V_OUT = 1.2V
1μF ^{IOUT ≤ 300mA}
40.2k
3025 TA01
1MHz V_IN Supply Rejection
50
45
C_OUT = 10μF
40
35
C_OUT = 1μF
30
25
20
15
10
5 ^{BIAS = 3.6V}
V_OUT = 1.2V
0
1.2 1.4 1.6
1.8 2.0
V_IN (V)
I_OUT = 100mA
I_OUT = 300mA
2.2 2.4 2.6
3025 TA01b
3025fd
1