Datasheet LTC1871-7 (Analog Devices)
| Manufacturer | Analog Devices |
| Description | High Input Voltage, Current Mode Boost, Flyback and SEPIC Controller |
| Pages / Page | 34 / 1 — FeaTures. DescripTion. Optimized for High Input Voltage Applications. … |
| File Format / Size | PDF / 398 Kb |
| Document Language | English |
FeaTures. DescripTion. Optimized for High Input Voltage Applications. Wide Chip Supply Voltage Range: 6V to 36V
Model Line for this Datasheet
Text Version of Document
LTC1871-7 High Input Voltage, Current Mode Boost, Flyback and SEPIC Controller
FeaTures DescripTion
n
Optimized for High Input Voltage Applications
The LTC®1871-7 is a current mode, boost, flyback and n
Wide Chip Supply Voltage Range: 6V to 36V
SEPIC controller optimized for driving 6V-rated MOSFETs n
Internal 7V Low Dropout Voltage Regulator
in high voltage applications. The LTC1871-7 works equally
Optimized for 6V-Rated MOSFETs
well in low or high power applications and requires few n
Current Mode Control Provides Excellent
components to provide a complete power supply solution.
Transient Response
The switching frequency can be set with an external resistor n
High Maximum Duty Cycle (92% Typ)
over a 50kHz to 1MHz range, and can be synchronized to n
±2% RUN Pin Threshold with 100mV Hysteresis
an external clock using the MODE/SYNC pin. Burst Mode n
±1% Internal Voltage Reference
operation at light loads, a low minimum operating supply n Micropower Shutdown: IQ = 10µA voltage of 6V and a low shutdown quiescent current of n Programmable Operating Frequency 10µA make the LTC1871-7 well suited for battery-operated (50kHz to 1MHz) with One External Resistor systems. For applications requiring constant frequency n Synchronizable to an External Clock Up to 1.3 × fOSC operation, Burst Mode operation can be defeated using n User-Controlled Pulse Skip or Burst Mode® Operation the MODE/SYNC pin. The LTC1871-7 is available in the n Output Overvoltage Protection 10-lead MSOP package. n Can be Used in a No RSENSE™ Mode for VDS < 36V
PARAMETER LTC1871-7 LTC1871
n Small 10-Lead MSOP Package INTVCC 7.0V 5.2V
applicaTions
INTVCC UV+ 5.6V 2.1V INTVCC UV– 4.6V 1.9V n Telecom Power Supplies L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks n 42V Automotive Systems of Linear Technology Corporation. No RSENSE is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. n 24V Industrial Controls n IP Phone Power Supplies
Typical applicaTion
D3 10BQ060 V VOUT IN 36V TO 72V 12V 2.2µF 3:1 0.4A 604k 100V 100k • 26.7k 47µF X7R T1 Q1 16V VP1-0076 FMMT625 • X5R D1 9.1V 10Ω 2.2nF RUN SENSE I D2 TH VIN 3.4k 4148 LTC1871-7 FB INTVCC 12.4k FREQ GATE M1 FDC2512 MODE/SYNC GND 0.1µF 110k 120k 4.7µF 0.12Ω X5R X5R 18717 F01
Figure 1. Small, Nonisolated 12V Flyback Telecom Housekeeping Supply
18717fd 1 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Applications Package Description Revision History Typical Application Related Parts
FeaTures DescripTion
n
Optimized for High Input Voltage Applications
The LTC®1871-7 is a current mode, boost, flyback and n
Wide Chip Supply Voltage Range: 6V to 36V
SEPIC controller optimized for driving 6V-rated MOSFETs n
Internal 7V Low Dropout Voltage Regulator
in high voltage applications. The LTC1871-7 works equally
Optimized for 6V-Rated MOSFETs
well in low or high power applications and requires few n
Current Mode Control Provides Excellent
components to provide a complete power supply solution.
Transient Response
The switching frequency can be set with an external resistor n
High Maximum Duty Cycle (92% Typ)
over a 50kHz to 1MHz range, and can be synchronized to n
±2% RUN Pin Threshold with 100mV Hysteresis
an external clock using the MODE/SYNC pin. Burst Mode n
±1% Internal Voltage Reference
operation at light loads, a low minimum operating supply n Micropower Shutdown: IQ = 10µA voltage of 6V and a low shutdown quiescent current of n Programmable Operating Frequency 10µA make the LTC1871-7 well suited for battery-operated (50kHz to 1MHz) with One External Resistor systems. For applications requiring constant frequency n Synchronizable to an External Clock Up to 1.3 × fOSC operation, Burst Mode operation can be defeated using n User-Controlled Pulse Skip or Burst Mode® Operation the MODE/SYNC pin. The LTC1871-7 is available in the n Output Overvoltage Protection 10-lead MSOP package. n Can be Used in a No RSENSE™ Mode for VDS < 36V
PARAMETER LTC1871-7 LTC1871
n Small 10-Lead MSOP Package INTVCC 7.0V 5.2V
applicaTions
INTVCC UV+ 5.6V 2.1V INTVCC UV– 4.6V 1.9V n Telecom Power Supplies L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks n 42V Automotive Systems of Linear Technology Corporation. No RSENSE is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. n 24V Industrial Controls n IP Phone Power Supplies
Typical applicaTion
D3 10BQ060 V VOUT IN 36V TO 72V 12V 2.2µF 3:1 0.4A 604k 100V 100k • 26.7k 47µF X7R T1 Q1 16V VP1-0076 FMMT625 • X5R D1 9.1V 10Ω 2.2nF RUN SENSE I D2 TH VIN 3.4k 4148 LTC1871-7 FB INTVCC 12.4k FREQ GATE M1 FDC2512 MODE/SYNC GND 0.1µF 110k 120k 4.7µF 0.12Ω X5R X5R 18717 F01
Figure 1. Small, Nonisolated 12V Flyback Telecom Housekeeping Supply
18717fd 1 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Applications Package Description Revision History Typical Application Related Parts
