Flyback regulator eases DC/DC converter design

Linear Technology Corp. has unveiled the LT8300, a low quiescent current monolithic flyback regulator that according to the company significantly simplifies the design of an isolated DC/DC converter. No optocoupler, third winding or signal transformer are required for feedback since the output voltage is sensed from the primary-side flyback signal. The device operates from 6-100V input voltage, has a 260mA, 150V power switch and delivers up to 2W of output power, geared for a variety of telecom, datacom, automotive, industrial and medical applications, added the company.

The LT8300 operates in a boundary mode, a current-mode control switching scheme, resulting in better than ±5 percent regulation over the full line, load and temperature range.

Boundary mode, also known as critical conduction mode (CCM), permits the use of a smaller transformer compared to equivalent continuous conduction mode designs. Low output ripple Burst Mode operation maintains high efficiency and helps extend battery run times at light load with its low quiescent current. The output voltage is easily set by a single external resistor and the transformer turns ratio. Several transformers identified in the data sheet can be used for numerous applications. Additional features include power, internal soft-start and adjustable undervoltage lockout. The high level of integration results in a simple, low component count, tightly regulated solution ideal for isolated power delivery.

The LT8300 is available in a small 5-lead ThinSOT package. Extended and industrial versions operate over a junction temperature range from -40°C to 125°C, and a high temperature automotive grade operates from -40°C to 150°C. Pricing starts at $2.95 each in 1000-piece quantities.