特点
High Efficiency: Up to 95%
Low Quiescent Current: Only 15μA with No Load
550kHz Constant Frequency Operation
2.65V to 10V Input Voltage Range
V
OUT
from 0.8V to V
IN
, I
OUT
to 1.2A
True PLL Frequency Locking from 350kHz to 750kHz
Power Good Output Voltage Monitor
Low Dropout Operation: 100% Duty Cycle
Burst Mode? or Pulse Skipping Operation
Current Mode Operation for Excellent Line and Load Transient Response
Shutdown Mode Draws <1μA Supply Current
?2% Output Voltage Accuracy
Overcurrent and Overtemperature Protected
Available in 16-Lead SSOP Package
典型应用
典型应用
描述
The LTC?1879 is a high efficiency monolithic synchronous buck regulator using a constant frequency, current mode architecture. Operating supply current is only 15μA with no load and drops to <1μA in shutdown. The input supply voltage range of 2.65V to 10V makes the LTC1879 ideally suited for both single and dual Li-Ion battery-powered applications. 100% duty cycle provides low dropout operation, extending battery life in portable systems.
The switching frequency is internally set to 550kHz, allowing the use of small surface mount inductors and capacitors. For noise sensitive applications, the LTC1879 can be externally synchronized from 350kHz to 750kHz. Burst Mode operation is inhibited during synchronization or when the SYNC/MODE pin is pulled low.
The internal synchronous rectifier switch increases efficiency and eliminates the need for an external Schottky diode. Low output voltages are easily supported with a 0.8V feedback reference voltage. The LTC1879 is available in a 16-lead SSOP package.