LTC3026_15 Datasheet, PDF (1/18 Pages) Linear Technology – 1.5A Low Input Voltage VLDO Linear Regulator

Features
n _{Input Voltage Range:}
1.14V to 3.5V (with Boost Enabled)
1.14V to 5.5V (with External 5V Boost)
n _{Low Dropout Voltage: 100mV at IOUT = 1.5A}
n _{Adjustable Output Range: 0.4V to 2.6V}
n _{Output Current: Up to 1.5A}
n _{Excellent Supply Rejection Even Near Dropout}
n _{Shutdown Disconnects Load from VIN and VBST}
n _{Low Operating Current: IIN = 950µA at VIN = 1.5V}
n _{Low Shutdown Current:}
I_IN < 1µA (Typ), I_BST = 0.1µA (Typ)
n _{Stable with 10µF or Greater Ceramic Capacitors}
n _{Short-Circuit, Reverse Current Protected}
n _{Overtemperature Protected}
n _{Available in 10-Lead MSOP and 10-Lead}
(3mm × 3mm) DFN Packages
Applications
n _{High Efficiency Linear Regulator}
n _{Post Regulator for Switching Supplies}
n _{Microprocessor Supply}
L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks
and ThinSOT, VLDO are trademarks of Linear Technology Corporation. All other trademarks are
the property of their respective owners.
LTC3026
1.5A Low Input Voltage
VLDO Linear Regulator
Description
The LTC^®3026 is a very low dropout (VLDO™) linear regula-
tor that can operate at input voltages down to 1.14V. The
device is capable of supplying 1.5A of output current with
a typical dropout voltage of only 100mV. To allow opera-
tion at low input voltages the LTC3026 includes a boost
converter that provides the necessary headroom for the
internal LDO circuitry.
Output current comes directly from the input supply to
maximize efficiency. The boost converter requires only a
small chip inductor and ceramic capacitor for operation.
Additionally, the boosted output voltage of one LTC3026
can supply the boost voltage for other LTC3026s, thus
requiring a single inductor for multiple LDOs. A user sup-
plied boost voltage can be used eliminating the need for
an inductor altogether.
The LTC3026 regulator is stable with 10µF or greater
ceramic output capacitors. The device has a low 0.4V
reference voltage which is used to program the output
voltage via two external resistors. The device also has
internal current limit, overtemperature shutdown, and
reverse output current protection. The LTC3026 is avail-
able in a small 10-lead MSOP or low profile (0.75mm)
10-lead 3mm × 3mm DFN package.
Typical Application
1.2V Output Voltage from 1.5V Input Supply
V_IN = 1.5V
L1
10µH
SW
5V BOOST ^BST
CONVERTER
IN
4.7µF _{0.4V +}
–
OUT
ADJ
OFF ON SHDN
LTC3026
GND
PG
L1: MURATA LQH2MCN100K02
4.7µF
8.06k
100k _4.02k
V_OUT = 1.2V,
1.5A
C_OUT
10µF
3026 TA01a
Dropout Voltage vs Output Current
150
100
1.2V
1.5V
2.0V
2.6V
50
0
0
0.5
1.0
1.5
I_OUT (A)
3026 TA01b
3026ff
1