LT1776 Datasheet | Linear Technology

LT1776 Wide Input Range, High Efficiency, Step-Down Switching Regulator Features s s s s DESCRIPTIO s s s s s Wide Input Range: 7.4V to 40V Tolerates Input Transients to 60V 700m A Peak Switch Rating Adaptive Switch Drive Maintains Efficiency at High Load Without Pulse Skipping at Light Load True Current Mode Control 200k Hz Fixed Operating Frequency Synchronizable to 400k Hz Low Supply Current in Shutdown: 30µA Available in 8-Pin SO and PDIP Packages The LT®1776 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 delivers excellent dynamic input supply rejection and short-circuit protection. The LT1776 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 LT1776 switch circuitry is also load dependent. At medium to high loads, the output switch circuitry maintains fast rise time for good efficiency. At light loads, rise time is deliberately reduced to avoid pulse skipping behavior. The available SO-8 package and 200k 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 Automotive DC/DC Converters Cellular Phone Battery Charger Accessories IEEE 1394 Step-Down Converters TYPICAL APPLICATIO VIN 8V TO 40V 1 5 VIN SHDN VCC VSW 39µF 63V 6 LT1776 FB 8 VC 7 2 3 90 80 100µH- MBR160 EFFICIENCY (%) + + 100µF 10V 5V 400m A 36.5k 1% 70 60 50 40 SYNC 2200p F 22k 100p F 12.1k 1% GND 4 30 20 - 43T #30 ON MAGNETICS MPP #55030 1776 F01 Figure 1 Efficiency vs VIN and ILOAD VIN = 10V VIN = 20V VIN = 30V VIN = 40V 1 10 100 LOAD CURRENT (m A) 1000 1776...