LT3710 Datasheet | Linear Technology

LT3710 Secondary Side Synchronous Post Regulator Features s s s s s s s s DESCRIPTIO Generates a Regulated Auxiliary Output in Isolated DC/DC Converters 0.8V ±1.5% Accurate Voltage Reference Dual N-Channel MOSFET Synchronous Drivers High Switching Frequency: Up to 500k Hz Programmable Current Limit Protection Programmable Soft-Start Automatic Frequency Synchronization Small 16-Pin Thermally Enhanced TSSOP Package The LT®3710 is a high efficiency step-down switching regulator intended for auxiliary outputs in single secondary winding, multiple output power supplies. The LT3710 drives dual synchronous N-channel MOSFETs and achieves high efficiency. With leading edge modulation, it operates well with either primary side peak current or voltage mode control. It is synchronized to the falling edge of the transformer secondary winding and can be used in both single-ended and double-ended isolated power converter topologies. A high speed operational amplifier is incorporated to achieve optimum pensation and fast transient response. A user selectable discontinuous conduction mode improves light load efficiency. The LT3710 is available in a thermally enhanced TSSOP-16 exposed pad power package. , LTC and LT are registered trademarks of Linear Technology Corporation. U APPLICATIO S s s s 48V Isolated DC/DC Converters Multiple Output Supplies Offline Converters TYPICAL APPLICATIO VIN 36V TO 72V L1 VCC BIAS 10k VDD VCC BOOST SYNC GBIAS 10p F LT3710 VFB FG ISNS LTC1698 10k 180p F TG BG LT3781 SG 0.01µF CS 680p F CSET TG 0.1µF SW ILP BG SS BGS VFB PGND CL- CL+ VAOUT 3.3k 33n F 2.32k 3.01k 220Ω Q2 B340A 4700p F 4.7µF Q1 L2 1.8µH CMDSH-3 VP CG - - - - SYNC OPTODRV VC + - VREF VFB GND ISOLATION BOUNDARY COUT2: POSCAP, 680µF/4V L2: SUMIDA CEP125-IR8MC-H Q1, Q2: SILICONIX Si7440DP PLEASE REFER TO FIGURE 3 IN THE APPLICATIONS SECTION FOR THE PLETE SCHEMATIC Figure 1. Simplified Single Secondary Winding 3.3V and 1.8V Output Isolated DC/DC Converter 3710f VOUT1...