SR086 Datasheet | Supertex Inc

Features - - Efficient operation without magnetics - - No high voltage capacitors - - Adjustable main output voltage (9.0 to 50V) - - Additional 3.3V internal regulator - - Up to 100m A bined output current - - Single BOM for 120VAC/230VAC - - Built-in soft start - - Less than 200m W standby power Applications - - White goods - - Household appliances - - Lighting controls - - Circuit breakers - - Keep-alive supplies General Description The Supertex SR086 is an inductorless switching regulator designed to operate directly from a rectified AC line. The operating principle is to turn on a pass transistor when the rectified AC is below the output voltage, and to turn it off when the output voltage reaches a specific level. A linear regulator supplied by VOUT provides an additional fixed 3.3V output. Efficiencies of around 55% may be realized for loads up to 1.0W in 120VAC applications, with around 50% efficiencies for loads up to 800m W in 230VAC applications. A logic-level enable input allows the SR086 to be disabled - useful when it is employed as a keep-alive power supply. WARNING! Galvanic isolation is not provided. Dangerous voltages are present when connected to the AC line. It is the responsibility of the designer employing the SR086 to ensure adequate safeguards are in place to protect the end user from electrical shock. The circuits shown in this datasheet are not guaranteed to meet surge and conducted EMI requirements. The effectiveness of these circuits may vary with a particular application. The designer should conduct tests to ascertain pliance with applicable standards and regulations. Typical Application Circuit 90 to 270VAC 50/60Hz 1.25A 275V 50A 1.0k V 1.0A STGD5NB120SZ 390kΩ 1.1MΩ 100n F 1.0µF 470µF Enable GATE VGD VOUT VIN FB EN VREG GND 3.3V @60m A 100n F VOUT 9.0 - 50VDC @100m A -...