Description

The LT1767EMS8E-3.3#TR is a 1.25MHz monolithic buck switching regulator designed for DC Switching Regulators. It features a high efficiency 1.5A, 0.22Ω switch and all the control circuitry required to complete a high frequency, current mode switching regulator. The current mode control provides fast transient response and excellent loop stability. The LT1767 is designed with new techniques to achieve high efficiency at high switching frequencies over a wide operating range. It also has a low dropout internal regulator that maintains consistent performance over a wide range of inputs from 24V systems to Li-Ion batteries. The operating supply current of 1mA improves efficiency, especially at lower output currents. It has a shutdown feature that reduces quiescent current to 6µA and synchronization allows an external logic level signal to increase the internal oscillator from 1.4MHz to 2MHz. It is available in an 8-pin MSOP fused leadframe package and a low thermal resistance exposed pad package. Full cycle-by-cycle short-circuit protection and thermal shutdown are provided, and its high frequency operation allows the reduction of input and output filtering components and permits the use of chip inductors.

Specifications and features

• 1.5A Switch in a Small MSOP Package
• Constant 1.25MHz Switching Frequency
• High Power Exposed Pad (MS8E) Package
• Wide Operating Voltage Range: 3V to 25V
• High Efficiency 0.22Ω Switch
• 1.2V Feedback Reference Voltage
• Fixed Output Voltages of 1.8V, 2.5V, 3.3V, 5V
• 2% Overall Output Tolerance
• Uses Low Profile Surface Mount Components
• Low Shutdown Current: 6µA
• Synchronizable to 2MHz
• Current Mode Loop Control
• Constant Maximum Switch Current Rating at All Duty Cycles*

Application Scenarios

• DSL Modems
• Portable Computers
• Wall Adapters
• Battery-Powered Systems
• Distributed Power

Comparison

- High efficiency at high switching frequencies
- Wide operating voltage range
- Constant maximum switch current rating at all duty cycles
- Synchronization capability

- Requires filtering components for high frequency operation
- Limited fixed output voltages available