特点
Dual Output Regulator in Tiny 10-Pin MSOP
High Efficiency: Up to 94%
Wide V
IN
Range: 2.65V to 9.8V
Constant Frequency 550kHz Operation
150mA LDO Regulator with Current Limit and Thermal Shutdown Protection
High Output Currents Easily Achieved
Burst Mode? Operation at Light Load
Low Dropout: 100% Duty Cycle
Current Mode Operation for Excellent Line and Load Transient Response
0.8V Reference Allows Low Output Voltages
Low Quiescent Current: 260μA Total
Shutdown Mode Draws Only 10μA Supply Current
Common Power Good Output for Both Supplies
典型应用
典型应用
描述
The LTC?3700 is a constant frequency current mode stepdown (buck) DC/DC controller with excellent AC and DC load and line regulation. The on-chip 150mA low dropout (LDO) linear regulator can be powered from the buck controller’s input supply, its own independent input supply or the buck regulator’s output. The buck controller incorporates an undervoltage lockout feature that shuts down the controller when the input voltage falls below 2.1V.
The buck regulator provides a ±2.5% output voltage accuracy. It consumes only 210μA of quiescent current in normal operation with the LDO consuming an additional 50μA. In shutdown, a mere 10μA (combined) is consumed.
For applications where efficiency is a prime consideration, the buck controller is configured for Burst Mode operation which enhances efficiency at low output current. To further maximize the life of a battery source, the external P-channel MOSFET is turned on continuously in dropout (100% duty cycle). High constant operating frequency of 550kHz allows the use of a small external inductor.
The LDO is protected by both current limit and thermal shutdown circuits.
The LTC3700 is available in a tiny 10-pin MSOP.