3A Fast Response Ultra Low Dropout Linear Regulators
The LP3856-ADJ fast ultra low-dropout linear regulators op-
erate from a +2.5V to +7.0V input supply. These ultra low
dropout linear regulators respond very quickly to step
changes in load, which makes them suitable for low voltage
microprocessor applications. The LP3856-ADJ is developed
on a CMOS process which allows low quiescent current op-
eration independent of output load current. This CMOS pro-
cess also allows the LP3856-ADJ to operate under extremely
low dropout conditions.
Dropout Voltage: Ultra low dropout voltage; typically 39mV
at 300mA load current and 390mV at 3A load current.
Ground Pin Current: Typically 4mA at 3A load current.
Shutdown Mode: Typically 10nA quiescent current when the
shutdown pin is pulled low.
Adjustable Output Voltage: The output voltage may be pro-
grammed via two external resistors.
Typical Application Circuit
**See Application Hints
© 2011 National Semiconductor Corporation
Ultra low dropout voltage
Stable with selected ceramic capacitors
Low ground pin current
Load regulation of 0.08%
10nA quiescent current in shutdown mode
Guaranteed output current of 3A DC
Available in TO-263 and TO-220 packages
−40°C to +125°C junction temperature range
Microprocessor power supplies
GTL, GTL+, BTL, and SSTL bus terminators
Power supplies for DSPs
High efficiency linear regulators
Other battery powered applications
March 4, 2011