Features

• Programmable dI/dt Limit
• Internally Limited dV/dt
• High Input Voltage: 48V Max
• 700mA Peak Switch Rating
• True Current Mode Control
• 100kHz Fixed Operating Frequency
• Synchronizable to 250kHz
• Low Supply Current in Shutdown: 30µA
• Low Thermal Resistance 16-Pin SO Package

Typical Application

Description

The LT1777 is a Buck (step-down) regulator designed for noise sensitive applications. It contains a dI/dt limiting circuit programmed via a small external inductor in the switching path. Internal circuitry also generates controlled dV/dt ramp rates.

The monolithic die includes all oscillator, control and protection circuitry. The part can accept operating input voltages as high as 48V, and contains an output switch rated at 700mA peak current. Current mode control offers excellent dynamic input supply rejection and short-circuit protection. The internal control circuitry is normally powered via the V_CC pin, thereby minimizing power drawn directly from the V_IN supply (see Applications Information). The fused-lead SO16 package and 100kHz switching frequency allow for minimal PC board area requirements.