LT1676 Datasheet | Linear Technology

LT1676 Wide Input Range, High Efficiency, Step-Down Switching Regulator Features s s s DESCRIPTIO s s s s s Wide Input Range: 7.4V to 60V 700m A Peak Switch Current Rating Adaptive Switch Drive Maintains Efficiency at High Load Without Pulse Skipping at Light Load True Current Mode Control 100k Hz Fixed Operating Frequency Synchronizable to 250k Hz Low Supply Current in Shutdown: 30µA Available in 8-Pin SO and PDIP Packages The LT®1676 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 700m A 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 VCC pin, thereby minimizing power drawn directly from the VIN 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 100k Hz switching frequency allow for minimal PC board area requirements. , LTC and LT are registered trademarks of Linear Technology Corporation. U APPLICATIO S s s s s Automotive DC/DC Converters Tele 48V Step-Down Converters Cellular Phone Battery Charger Accessories IEEE 1394 Step-Down Converters TYPICAL APPLICATIO VIN 8V TO 50V 1 5 VIN 2 SHDN VCC 3 VSW LT1676 FB 8 VC 7 220µH- MBR160 100µF 10V EFFICIENCY (%) + 39µF 63V 6 + 5V 400m A 36.5k 1% SYNC 2200p F 22k 100p F 12.1k 1% GND 4 - 65T #30 ON MAGNETICS MPP #55030 1676 F01 Figure 1 Efficiency vs VIN and ILOAD 90 80 70 60 50 40 VIN = 12V 30 20 1 VIN = 24V VIN = 36V VIN = 48V 10 ILOAD (m A) 1676 TA01 100...