The ADP2109 is a high efficiency, low quiescent current stepdown
dc-to-dc converter with an internal discharge switch that
allows automatic discharge of the output capacitor in an ultra
small 5-ball WLCSP package.
The total solution only requires three tiny external components. It
uses a proprietary high-speed current mode, constant frequency
PWM control scheme for excellent stability and transient response.
To ensure the longest battery life in portable applications, the
ADP2109 has a power save mode that reduces the switching
frequency under light load conditions.
The ADP2109 runs on input voltages of 2.3 V to 5.5 V, which
allow for single lithium or lithium polymer cell, multiple alkaline or
NiMH cells, PCMCIA, USB, and other standard power sources.
The maximum load current of 600 mA is achievable across the
input voltage range.
The ADP2109 is available in fixed output voltages of 1.8 V, 1.2 V,
and 1.0 V. All versions include an internal power switch and
synchronous rectifier for minimal external part count and high
efficiency. The ADP2109 has an internal soft start and internal
compensation. During logic-controlled shutdown, the input is
disconnected from the output and the ADP2109 draws less than
1 μA from the input source.
Other key features include undervoltage lockout to prevent deep
battery discharge and soft start to prevent input current overshoot
at startup. The ADP2109 is available in a 5-ball WLCSP.
Other key features include undervoltage lockout to prevent deep
battery discharge and soft start to prevent input current overshoot
at startup. The ADP2109 is available in a 5-ball WLCSP.
The ADP2108 provides the same features and operations as the
ADP2109 without the discharge switch and is available in both
WLCSP and TSOT packages.
Applications
- PDAs and palmtop computers
- Wireless handsets
- Digital audio, portable media players
- Digital cameras, GPS navigation units
