Linear Technology Introduces Low Quiescent Current Single Row Flyback Regulator

Linear Technology has introduced the LT8300, a low quiescent current monolithic flyback regulator that greatly simplifies the design of isolated DC/DC converters. Because the output voltage is detected from the primary flyback signal, there is no need for feedback from the optocoupler, third winding, or signal transformer. Operating from an input voltage range of 6V to 100V, the LT8300 features a 260mA, 150V power switch that provides up to 2W of output power and is ideal for a wide variety of telecommunications, datacom, automotive, industrial and medical applications.

The LT8300 operates in a boundary-mode, current-mode controlled switching circuit that achieves ±5% regulation across the entire voltage, load, and temperature range. Boundary mode, also known as critical conduction mode (CCM), allows the use of smaller transformers than equivalent continuous conduction mode designs. Burst Mode® operation with low output Burst Mode® maintains high efficiency and, with its low quiescent current, helps extend battery run time at light loads. The output voltage is easily set with a single external resistor and transformer turns ratio. Several transformers listed in the datasheet can be used for many applications. Other features include power supply, internal soft start, and adjustable undervoltage lockout. High integration enables a solution that is simple, has a small number of components, is tightly regulated, and is suitable for isolated power delivery.

The LT8300 is available in a small 5-lead ThinSOTTM package. The extended and industrial versions operate over a junction temperature range of -40°C to 125°C. High-temperature automotive grades operate over the -40°C to 150°C temperature range. The purchase price for 1,000 tablets is US$2.95 per tablet.


Photo Caption: Micropower Isolated Monolithic Flyback Regulator Performance Summary: LT8300

· 6V to 100V VIN range · Integrated 260mA, 150V integrated power switch · No need for optocoupler, transformer or third winding feedback · Low quiescent current of 330μA at operation · Few component count · Boundary mode operation · Set VOUT with a single external resistor

· Off-the-shelf transformers · Programmable undervoltage lockout · Internal soft start