LT1676 Datasheet

• Wide Input Range: 7.4V to 60V
• 700mA Peak Switch Current Rating
• Adaptive Switch Drive Maintains Efficiency at High Load Without Pulse Skipping at Light Load
• True Current Mode Control
• 100kHz Fixed Operating Frequency
• Synchronizable to 250kHz
• Low Supply Current in Shutdown: 30µA
• Available in 8-Pin SO and PDIP Packages

• Automotive DC/DC Converters
• Telecom 48V Step-Down Converters
• Cellular Phone Battery Charger Accessories
• IEEE 1394 Step-Down Converters

The LT1676 is a wide input range, high efficiency Buck (step-down) switching regulator. The monolithic die includes all oscillator, control and protection circuitry. The part can accept input voltages as high as 60V and contains an output switch rated at 700mA peak current. Current mode control offers excellent dynamic input supply rejection and short-circuit protection.

The LT1676 contains several features to enhance efficiency. 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 action of the LT1676 switch circuitry is also load dependent. At medium to high loads, the output switch circuitry maintains high rise time for good efficiency. At light loads, rise time is deliberately reduced to avoid pulse skipping behavior.

The available SO-8 package and 100kHz switching frequency allow for minimal PC board area requirements.