Features

• N-Channel MOSFET Drive
• Implements Boost, Step-Down, SEPIC and Inverting Regulators
• Wide V_IN Range: 3.5V to 36V Operation
• Wide V_OUT Range: 1.19V to 30V in Step-Down Configuration
• ±1% 1.19V Reference
• Low Dropout Operation: 95% Duty Cycle
• 200kHz Fixed Frequency
• Low Standby Current
• Very High Efficiency
• Remote Output Voltage Sense
• Logic-Controlled Micropower Shutdown
• Internal Diode for Bootstrapped Gate Drive
• Current Mode Operation for Excellent Line and Load Transient Response
• Available in an 8-Lead SO Package

Typical Application

Description

The LTC1624 is a current mode switching regulator controller that drives an external N-channel power MOSFET using a fixed frequency architecture. It can be operated in all standard switching configurations including boost, step-down, inverting and SEPIC. Burst Mode operation provides high efficiency at low load currents. A maximum high duty cycle limit of 95% provides low dropout operation which extends operating time in battery-operated systems.

The operating frequency is internally set to 200kHz, allowing small inductor values and minimizing PC board space. The operating current level is user-programmable via an external current sense resistor. Wide input supply range allows operation from 3.5V to 36V (absolute maximum).

A multifunction pin (I_TH/RUN) allows external compensation for optimum load step response plus shutdown. Soft start can also be implemented with the I_TH/RUN pin to properly sequence supplies.