The LTC3806 is a current mode synchronous flyback controller that drives N-channel power MOSFETs and requires very few external components. It is intended for medium power applications where multiple outputs are required. Synchronous rectification provides higher efficiency and improved output cross regulation than nonsynchronous converters. The IC contains all the necessary control circuitry including a 250kHz oscillator, precision undervoltage lockout circuit with hysteresis, gate drivers for primary and synchronous switches, current mode control circuitry and soft-start circuitry. Programmable soft-start reduces inrush currents. This makes it easier to design compliant Power Over Ethernet supplies. Low start-up current reduces power dissipation in the start-up resistor and reduces the size of the external start-up capacitor. The LTC3806 is available in a 12-pin, exposed pad DFN package.
The LTC3806 is a current mode synchronous flyback controller designed to drive N-channel power MOSFETs with very few external components. It is intended for medium power applications requiring multiple outputs, such as telecom supplies, automotive systems, and Power over Ethernet (PoE) supplies.
Key features include high efficiency at full load due to synchronous rectification, better cross-regulation than nonsynchronous converters, and a constant frequency operation of 250kHz to prevent audible noise. The device integrates an oscillator, precision undervoltage lockout circuitry, gate drivers for primary and synchronous switches, current mode control, and soft-start functionality.
| Oscillator Frequency | 250 kHz (Typ) |
|---|---|
| Maximum Duty Cycle | 89% (Typ) |
| INTVcc Output Voltage | 6.9 V (Typ) |
| Feedback Voltage Threshold | 1.230 V (Typ) |
| Package Type | 12-Pin DFN |
The typical oscillator frequency is 250 kHz.
It is intended for medium power applications where multiple outputs are required, such as telecom supplies and automotive systems.
The device is available in a 12-pin, exposed pad DFN package.