CIE Components in Electronics
Linear Technology has launched the LT8310, a primary-side synchronous forward controller. The LT8310 operates over an input voltage range of 6V to 100V and is targeted for power levels up to 200W. It is able to provide a drive signal for secondary-side synchronous rectification to improve efficiency.
Output voltage regulation of ±8% can be attained without the use of an opto-coupler. When an opto-coupler is used, ±1.5% regulation can be realized. A programmable volt-second clamp provides a safeguard for transformer reset that prevents saturation and protects the MOSFET. This function optimizes the transformer and MOSFET, reducing solution size.
The LT8310 computes the duty cycle required to create a constant VOUT in open loop applications, thereby simplifying the design. In closed loop applications it limits maximum VOUT if the opto-coupler path breaks open.
Additional features include programmable overcurrent protection, adjustable input undervoltage, overvoltage lockout and built-in thermal shutdown. The LT8310 has a programmable 100kHz to 500kHz operating switching frequency and can be synchronized to an external clock, enabling the use of a wide range of output inductor values and transformer sizes.
The device is available in a TSSOP-20 package with several pins removed for high voltage spacing. The LT8310 E- and I-grade versions operate from a -40°C to 125°C junction temperature. The LT8310 H grade is guaranteed to operate from a -40°C to 150°C operating junction temperature. The LT8310 MP grade is guaranteed to operate from -55°C to 150°C operating junction temperature.
