Datasheet LT3710 (Analog Devices)
| Manufacturer | Analog Devices |
| Description | Secondary Side Synchronous Post Regulator |
| Pages / Page | 12 / 1 — FEATURES. DESCRIPTIO. Generates a Regulated Auxiliary Output in Isolated. … |
| File Format / Size | PDF / 228 Kb |
| Document Language | English |
FEATURES. DESCRIPTIO. Generates a Regulated Auxiliary Output in Isolated. DC/DC Converters. 0.8V. 1.5% Accurate Voltage Reference
Model Line for this Datasheet
Text Version of Document
LT3710 Secondary Side Synchronous Post Regulator
U FEATURES DESCRIPTIO
■
Generates a Regulated Auxiliary Output in Isolated
The LT®3710 is a high efficiency step-down switching
DC/DC Converters
regulator intended for auxiliary outputs in single second- ■
0.8V
±
1.5% Accurate Voltage Reference
ary winding, multiple output power supplies. ■
Dual N-Channel MOSFET Synchronous Drivers
The LT3710 drives dual synchronous N-channel MOSFETs ■
High Switching Frequency: Up to 500kHz
and achieves high efficiency. With leading edge modula- ■
Programmable Current Limit Protection
tion, it operates well with either primary side peak current ■ Programmable Soft-Start or voltage mode control. It is synchronized to the falling ■ Automatic Frequency Synchronization edge of the transformer secondary winding and can be ■ Small 16-Pin Thermally Enhanced TSSOP Package used in both single-ended and double-ended isolated power converter topologies. A high speed operational
U
amplifier is incorporated to achieve optimum compensa-
APPLICATIO S
tion and fast transient response. A user selectable discon- ■ 48V Isolated DC/DC Converters tinuous conduction mode improves light load efficiency. ■ Multiple Output Supplies The LT3710 is available in a thermally enhanced TSSOP-16 ■ Offline Converters exposed pad power package. , LTC and LT are registered trademarks of Linear Technology Corporation.
U TYPICAL APPLICATIO
L1 VOUT1 3.3V AT 10A VIN VCC 36V BIAS TO 72V 10k VDD VCC BOOST CMDSH-3 VCOMP SYNC GBIAS • • 10pF 4.7µF CG LT3710 V L2 FB CSET TG Q1 CS 1.8µH 0.006Ω VOUT2 FG 680pF 0.1µF 1.8V SW AT 10A + ISNS ILCOMP BG Q2 B340A 4700pF COUT2 LTC1698 10k SS VAOUT 0.01µF BGS 3.3k 180pF 3.01k 220Ω TG BG SG SYNC 33nF • • LT3781 PGND VFB CL– CL+ 2.32k 3710 F01 OPTODRV VREF V + GND C VFB – COUT2: POSCAP, 680µF/4V PLEASE REFER TO FIGURE 3 ISOLATION L2: SUMIDA CEP125-IR8MC-H IN THE APPLICATIONS SECTION BOUNDARY Q1, Q2: SILICONIX Si7440DP FOR THE COMPLETE SCHEMATIC
Figure 1. Simplified Single Secondary Winding 3.3V and 1.8V Output Isolated DC/DC Converter
3710f 1
U FEATURES DESCRIPTIO
■
Generates a Regulated Auxiliary Output in Isolated
The LT®3710 is a high efficiency step-down switching
DC/DC Converters
regulator intended for auxiliary outputs in single second- ■
0.8V
±
1.5% Accurate Voltage Reference
ary winding, multiple output power supplies. ■
Dual N-Channel MOSFET Synchronous Drivers
The LT3710 drives dual synchronous N-channel MOSFETs ■
High Switching Frequency: Up to 500kHz
and achieves high efficiency. With leading edge modula- ■
Programmable Current Limit Protection
tion, it operates well with either primary side peak current ■ Programmable Soft-Start or voltage mode control. It is synchronized to the falling ■ Automatic Frequency Synchronization edge of the transformer secondary winding and can be ■ Small 16-Pin Thermally Enhanced TSSOP Package used in both single-ended and double-ended isolated power converter topologies. A high speed operational
U
amplifier is incorporated to achieve optimum compensa-
APPLICATIO S
tion and fast transient response. A user selectable discon- ■ 48V Isolated DC/DC Converters tinuous conduction mode improves light load efficiency. ■ Multiple Output Supplies The LT3710 is available in a thermally enhanced TSSOP-16 ■ Offline Converters exposed pad power package. , LTC and LT are registered trademarks of Linear Technology Corporation.
U TYPICAL APPLICATIO
L1 VOUT1 3.3V AT 10A VIN VCC 36V BIAS TO 72V 10k VDD VCC BOOST CMDSH-3 VCOMP SYNC GBIAS • • 10pF 4.7µF CG LT3710 V L2 FB CSET TG Q1 CS 1.8µH 0.006Ω VOUT2 FG 680pF 0.1µF 1.8V SW AT 10A + ISNS ILCOMP BG Q2 B340A 4700pF COUT2 LTC1698 10k SS VAOUT 0.01µF BGS 3.3k 180pF 3.01k 220Ω TG BG SG SYNC 33nF • • LT3781 PGND VFB CL– CL+ 2.32k 3710 F01 OPTODRV VREF V + GND C VFB – COUT2: POSCAP, 680µF/4V PLEASE REFER TO FIGURE 3 ISOLATION L2: SUMIDA CEP125-IR8MC-H IN THE APPLICATIONS SECTION BOUNDARY Q1, Q2: SILICONIX Si7440DP FOR THE COMPLETE SCHEMATIC
Figure 1. Simplified Single Secondary Winding 3.3V and 1.8V Output Isolated DC/DC Converter
3710f 1
