LT1936 1.4A, 500kHz Step-Down Switching Regulator FEATURESDESCRIPTION ■ Wide Input Range: 3.6V to 36V The LT®1936 is a current mode PWM step-down DC/DC ■ Short-Circuit Protected Over Full Input Range converter with an internal 1.9A power switch, packaged ■ 1.9A Guaranteed Minimum Switch Current in a tiny, thermally enhanced 8-lead MSOP. The wide in- ■ 5V at 1.4A from 10V to 36V Input put range of 3.6V to 36V makes the LT1936 suitable for ■ 3.3V at 1.4A from 7V to 36V Input regulating power from a wide variety of sources, including ■ 5V at 1.2A from 6.3V to 36V Input automotive batteries, 24V industrial supplies and unregu- ■ 3.3V at 1.2A from 4.5V to 36V Input lated wall adapters. Its high operating frequency allows the ■ Output Adjustable Down to 1.20V use of small, low cost inductors and ceramic capacitors, ■ 500kHz Fixed Frequency Operation resulting in low, predictable output ripple. ■ Soft-Start Cycle-by-cycle current limit, frequency foldback and ■ Uses Small Ceramic Capacitors thermal shutdown provide protection against shorted ■ Internal or External Compensation outputs, and soft-start eliminates input current surge ■ Low Shutdown Current: <2μA during start-up. Transient response can be optimized by ■ Thermally Enhanced 8-Lead MSOP Package using external compensation components, or board space can be minimized by using internal compensation. The APPLICATIONS low current (<2μA) shutdown mode enables easy power management in battery-powered systems. ■ Automotive Battery Regulation ■ Industrial Control Supplies L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. ■ Unregulated Wall Adapters TYPICAL APPLICATION3.3V Step-Down ConverterEffi ciency 95 V V IN IN = 12V 4.5V TO 36V 90 VOUT = 5V 0.22μF VIN BOOST 10μH VOUT ON OFF SHDN SW 3.3V 85 1.2A VOUT = 3.3V 4.7μF LT1936 17.4k 80 COMP FB V EFFICIENCY (%) C GND 75 10k 22μF 70 1936 TA01a 65 0 0.5 1 1.5 LOAD CURRENT (A) 1936 TA01b 1936fd 1