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. It operates over a 3.7-30V input voltage range and is used with a primary-side IC, such as the LT3752/-1.
The MOSFET driver 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.
The LT8311 is available in E-, I-, H- and MP-grade variants: the E- and I-grade versions operate over a temperature range from -40 to +125°C; the H-grade version operates over a temperature range from -40 to +150°C; and the MP-grade version operates over a temperature range from -55 to +150°C. Supplied in a TSSOP-20 package with several pins removed for high peak voltage spacing, pricing starts from $3.06 (USD) each in 1,000 unit quantities.