SR036DB1

SR036DB1 Inductorless Switching Power Supply Introduction The Supertex SR036 is an inductorless, dual output off-line regulator intended for 120/240VAC line operation. The operating principle is to activate a pass element between line and load only when the input voltage is lower than a certain value. Thus conduction only occurs with a low voltage drop across the pass element, resulting in more efficient operation compared to a standard linear regulator. The SR036DB1 demo board contains all the circuitry needed to supply a low-current (<40mA) load. Included are input protection circuitry, a full wave bridge rectifier, a pass element, and output capacitors. Specifications AC Input Output Voltages VUNREG VREG Output Current IUNREG + IREG Efficiency ACIN=120VAC 60Hz, IU=40mA, IR=0mA 24VAC to 264VAC 40Hz to 100Hz 18V±20% 3.3V ±10% 40mA @ 120VAC 30mA @ 240VAC 40% typ Board Layout and Connections Q1 Z1 ACIN F1 D1 IC1 C2 C1 GND WARNING!!! Do not connect to scope ground or to the ground of other earth-grounded instruments. Doing so will short the AC line, resulting in damage to the circuit and/or instrument. Either use an isolation transformer on the AC line, use a differential probe, or use a floating, battery-powered instrument to make measurements. VREG VUNREG WARNING!!! No galvanic isolation. Dangerous voltages are present when connected to the AC mains. ACIN Connect to the AC line. Neutral to top, hot to bottom. VUNREG The unregulated output. Nominal output voltage is ...