The LT8311’s unique preactive mode eliminates the need for a signal transformer for primary to secondary-side communication by sensing signals on the secondary side to control synchronous rectification. This mode reduces

component count and solution size.

The LT8311 operates over a 3.7V to 30V input voltage range and is used with a primary-side IC, such as the LT3752/-1. The complete forward converter can operate with input voltages ranging from 6.5V up to 400V+ making it ideal for a wide range of applications including hybrid/electric vehicle automotive requirements.

Furthermore, the LT8311 combines a 10mA opto-driver and a feedback loop error amplifier to enable output voltage feedback from the secondary to the primary side. The entire system provides fixed frequency peak current mode control that has excellent line/load regulation and fast transient response. Additional features include a 1.5% reference voltage, a power good monitor and programmable soft-start of the output voltage.

Features:

－ Eliminates Signal Transformer for Synchronous Rectification Control

－ LT8311 Input Voltage Range:3.7V to 30V

－ Operates with Primary-Side IC for up to 400V+ Input Voltages

－ 1.5% Reference Voltage

－ Onboard 10mA Opto-Coupler Driver

－ Output Power Good Indicator

－ Programmable Soft-Start of Output Voltage

－ Onboard Feedback Error Amplifier

－ Extended & Industrial Grades:-40°C to 125°C Operating Junction Temp

－ Automotive Temp Grade:-40°C to 150°C Operating Junction Temp

－ Military Temp Grade:-55°C to 150°C Operating Junction Temp