Datasheet LTC1265, LTC1265-3.3, LTC1265-5 (Analog Devices)
| Manufacturer | Analog Devices |
| Description | 1.2A, High Efficiency Step-Down DC/DC Converter |
| Pages / Page | 16 / 1 — FEATURES. DESCRIPTIO. High Efficiency: Up to 95%. Internal 0.3. Power … |
| File Format / Size | PDF / 244 Kb |
| Document Language | English |
FEATURES. DESCRIPTIO. High Efficiency: Up to 95%. Internal 0.3. Power Switch (VIN = 10V). APPLICATIO S. TYPICAL APPLICATIO
Model Line for this Datasheet
Text Version of Document
LTC1265/LTC1265-3.3/LTC1265-5 1.2A, High Efficiency Step-Down DC/DC Converter
U FEATURES DESCRIPTIO
■
High Efficiency: Up to 95%
The LTC®1265 is a monolithic step-down current mode ■ Current Mode Operation for Excellent Line and Load DC/DC converter featuring Burst Mode TM operation at low Transient Response output current. The LTC1265 incorporates a 0.3Ω switch ■
Internal 0.3
Ω
Power Switch (VIN = 10V)
(VIN =10V) allowing up to 1.2A of output current. ■ Short-Circuit Protection Under no load condition, the converter draws only 160µA. ■ Low Dropout Operation: 100% Duty Cycle In shutdown it typically draws a mere 5µA making this ■ Low-Battery Detector converter ideal for current sensitive applications. In drop- ■ Low 160µA Standby Current at Light Loads out the internal P-channel MOSFET switch is turned on ■ Active-High Micropower Shutdown: IQ < 15µA continuously maximizing the life of the battery source. The ■ Peak Inductor Current Independent of Inductor Value LTC1265 incorporates automatic power saving Burst Mode ■ Available in 14-pin SO Package operation to reduce gate charge losses when the load
U
currents drop below the level required for continuous
APPLICATIO S
operation. ■ 5V to 3.3V Conversion The inductor current is user-programmable via an external ■ Distributed Power Systems current sense resistor. Operation up to 700kHz permits ■ Step-Down Converters the use of small surface mount inductors and capacitors. ■ Inverting Converters , LTC and LT are registered trademarks of Linear Technology Corporation. ■ Memory Backup Supply Burst Mode is a trademark of Linear Technology Corporation. ■ Portable Instruments ■ Battery-Powered Equipment ■ Cellular Telephones
U TYPICAL APPLICATIO
VIN 5.4V TO
LTC1265-5 Efficiency
12V + C ††† IN 68µF 0.1µF 100 L1* R PWR V SENSE** 20V IN VIN 33µH 0.1Ω VOUT V SHDN SW IN = 6V 5V 95 1A LTC1265-5 V D1† IN = 9V 1k + C †† OUT I 90 TH PGND 220µF VIN = 12V 10V 3900pF 85 C 130pF T SENSE+ 1000pF EFFICIENCY (%) 80 L = 33µH SENSE– VOUT = 5V 75 * COILTRONICS CTX33-4 RSENSE = 0.1Ω SGND ** IRC LRC2010-01-R100-J CT = 130pF † MBRS130LT3 70 †† AVX TPSE227K010 0.01 0.10 1.00 ††† AVX TPSE686K020 LOAD CURRENT (A) LTC1265-FO1 LTC1265 TA01
Figure 1. High Efficiency Step-Down Converter
1
U FEATURES DESCRIPTIO
■
High Efficiency: Up to 95%
The LTC®1265 is a monolithic step-down current mode ■ Current Mode Operation for Excellent Line and Load DC/DC converter featuring Burst Mode TM operation at low Transient Response output current. The LTC1265 incorporates a 0.3Ω switch ■
Internal 0.3
Ω
Power Switch (VIN = 10V)
(VIN =10V) allowing up to 1.2A of output current. ■ Short-Circuit Protection Under no load condition, the converter draws only 160µA. ■ Low Dropout Operation: 100% Duty Cycle In shutdown it typically draws a mere 5µA making this ■ Low-Battery Detector converter ideal for current sensitive applications. In drop- ■ Low 160µA Standby Current at Light Loads out the internal P-channel MOSFET switch is turned on ■ Active-High Micropower Shutdown: IQ < 15µA continuously maximizing the life of the battery source. The ■ Peak Inductor Current Independent of Inductor Value LTC1265 incorporates automatic power saving Burst Mode ■ Available in 14-pin SO Package operation to reduce gate charge losses when the load
U
currents drop below the level required for continuous
APPLICATIO S
operation. ■ 5V to 3.3V Conversion The inductor current is user-programmable via an external ■ Distributed Power Systems current sense resistor. Operation up to 700kHz permits ■ Step-Down Converters the use of small surface mount inductors and capacitors. ■ Inverting Converters , LTC and LT are registered trademarks of Linear Technology Corporation. ■ Memory Backup Supply Burst Mode is a trademark of Linear Technology Corporation. ■ Portable Instruments ■ Battery-Powered Equipment ■ Cellular Telephones
U TYPICAL APPLICATIO
VIN 5.4V TO
LTC1265-5 Efficiency
12V + C ††† IN 68µF 0.1µF 100 L1* R PWR V SENSE** 20V IN VIN 33µH 0.1Ω VOUT V SHDN SW IN = 6V 5V 95 1A LTC1265-5 V D1† IN = 9V 1k + C †† OUT I 90 TH PGND 220µF VIN = 12V 10V 3900pF 85 C 130pF T SENSE+ 1000pF EFFICIENCY (%) 80 L = 33µH SENSE– VOUT = 5V 75 * COILTRONICS CTX33-4 RSENSE = 0.1Ω SGND ** IRC LRC2010-01-R100-J CT = 130pF † MBRS130LT3 70 †† AVX TPSE227K010 0.01 0.10 1.00 ††† AVX TPSE686K020 LOAD CURRENT (A) LTC1265-FO1 LTC1265 TA01
Figure 1. High Efficiency Step-Down Converter
1
