LTC3035_15 Datasheet, PDF (1/12 Pages) Linear Technology – 300mA VLDO Linear Regulator with Charge Pump Bias Generator

LTC3035
300mA VLDO Linear
Regulator with Charge Pump
Bias Generator
FEATURES
■ _{Wide Input Voltage Range: 1.7V to 5.5V}
■ _{Wide Adjustable Output Voltage Range:}
0.4V to 3.6V
■ _{Built-In Charge Pump Generates High Side Bias}
■ _{Very Low Dropout: 45mV at 300mA}
■ _{±2% Voltage Accuracy Over Temperature,}
Supply, Load
■ _{Fast Transient Recovery}
■ _{Low Operating Current: IIN = 100µA Typ}
■ _{Low Shutdown Current: IIN = 1µA Typ}
■ _{Stable with Ceramic Capacitor Down to 1µF}
■ _{Output Current Limit}
■ _{Thermal Overload Protected}
■ _{Reverse Output Current Protected}
■ _{Available in 8-Lead (3mm × 2mm) DFN Package}
U
APPLICATIO S
■ _{Li-Ion to 3.3V Low Dropout Supplies}
■ _{2 × AA to 1.8V Low Dropout Supplies}
■ _{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}
DESCRIPTIO
The LTC^®3035 is a micropower, VLDO™ (very low drop-
out) linear regulator which operates from input voltages as
low as 1.7V. The device is capable of supplying 300mA of
output current with a typical dropout voltage of only
45mV. To allow operation at low input voltages the LTC3035
includes a charge pump generator that provides the nec-
essary bias voltage for the internal LDO circuitry. Output
current comes directly from the input supply for high
efficiency regulation. The charge pump bias generator
requires only a 0.1µF flying capacitor and a 1µF bypass
capacitor for operation. The low 0.4V internal reference
voltage allows the LTC3035 to be programmed to much
lower output voltages than commonly available in LDOs.
The output voltage is programmed via two tiny SMD
resistors. The LTC3035’s low quiescent current makes it
an ideal choice for use in battery-powered systems.
Other features include high output voltage accuracy, ex-
cellent transient response, stability with ultralow ESR
ceramic capacitors as small as 1µF, short-circuit and
thermal overload protection, output current limiting and
reverse output current protection. The LTC3035 is avail-
able in a tiny, low profile (3mm × 2mm × 0.75mm) 8-lead
DFN package.
, LTC and LT are registered trademarks of Linear Technology Corporation.
VLDO is a trademark of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
Protected by U.S. Patents, including 6411531, others pending.
TYPICAL APPLICATIO
3.3V Output Voltage from Li-Ion Battery
0.1µF
Li-Ion
BATTERY
3.4V TO 4.2V
CP
CM
BIAS
BIAS
IN ^GENERATOR
1µF 0.4V +
–
OUT
LTC3035
ADJ
OFF ON
SHDN GND
C_BIAS
1µF
294k
V_OUT
3.3V
C_{OUT 300mA}
1µF
40.2k
3035 TA01a
Dropout Voltage vs Load Current
70
T_A = 25°C
60
50
40
30
20
10
0
0 50 100 150 200 250 300
I_OUT (mA)
3035 TA01b
3035f
1