Analog Devices Inc. ADP2140ACPZ1218R7

Description
The ADP2140 is a highly efficient, low quiescent current buck converter with a 300 mA LDO regulator. It is packaged in a small 10-lead 3 mm x 3 mm LFCSP. The total solution requires only four tiny external components.
The buck regulator uses a proprietary high-speed current-mode, constant frequency, pulse-width modulation (PWM) control scheme for excellent stability and transient response. To ensure the longest battery life in portable applications, the ADP2140 has a power-saving variable frequency mode to reduce switching frequency under light loads.
The LDO is a low quiescent current, low dropout linear regulator designed to operate in a split supply mode with Vis as low as 1.65 V. The low input voltage minimum allows the LDO to be powered from the output of the buck regulator, increasing efficiency and reducing power dissipation.
The ADP2140 runs from input voltages of 2.3 V to 5.5 V, allowing single Li /Li-polymer cell, multiple alkaline/NiMH cell, PCMCIA, and other standard power sources.

Features
Input voltage range: 2.3 V to 5.5 V
LDO input (VIN2) 1.65 V to 5.5 V
Buck output voltage range: 1.0 V to 3.3 V
LDO output voltage range: 0.8 V to 3.3 V
Buck output current: 600 mA
LDO output current: 300 mA
LDO quiescent current: 22 μA with zero load
Buck quiescent current: 20 μA in PSM mode
Low shutdown current: <0.3 μA
Low LDO dropout 110 mV @ 300 mA load
High LDO PSRR
65 dB @ 10 kHz at Vout2 = 1.2 V
55 dB @ 100 kHz at Voutz = 1.2 V
Low noise LDO: 40 μV rms at VouTZ = 1.2 V
Initial accuracy: ±1%
Current-limit and thermal overload protection
Power-good indicator
Optional enable sequencing
10-lead 0.75 mm x 3 mm x 3 mm LFCSP package

Applications
Mobile phones
Personal media players
Digital camera and audio devices
Portable and battery-powered equipment