Features

• High Efficiency: Up to 95%
• V_IN Range: 2.5V to 5.5V
• High Frequency Operation: Up to 4MHz
• Selectable Low Ripple (Typical 25mV_p-p) Burst Mode® Operation: I_Q = 40μA
• Stable with Ceramic Capacitors
• Uses Tiny Capacitors and Inductor
• Low R_DS(ON) Internal Switches: 0.15Ω
• Current Mode Operation for Excellent Line and Load Transient Response
• Short-Circuit Protected
• Low Dropout Operation: 100% Duty Cycle
• Low Shutdown Current: I_Q ≤ 1μA
• Output Voltages from 0.6V to 5V
• Synchronizable to External Clock
• Supports Pre-Biased Outputs
• Small 10-Lead (3mm × 3mm) DFN or MSOP Package

Typical Application

Description

The LTC®3565 is a constant frequency, synchronous step-down DC/DC converter. Intended for medium power applications, it operates from a 2.5V to 5.5V input voltage range and has a user-configurable operating frequency up to 4MHz, allowing the use of tiny, low cost capacitors and inductors 1mm or less in height. The output voltage is adjustable from 0.6V to 5.5V. Internal synchronous power switches provide high efficiency. The LTC3565’s current mode architecture and external compensation allow the transient response to be optimized over a wide range of loads and output capacitors.

The LTC3565 can be configured for automatic power saving Burst Mode operation (I_Q = 40μA) to reduce gate charge losses when the load current drops below the level required for continuous operation. For reduced noise and RF interference, the SYNC/MODE pin can be configured to skip pulses or provide forced continuous operation.

To further maximize battery life, the P-channel MOSFET is turned on continuously in dropout (100% duty cycle). In shutdown, the device draws <1μA.