Datasheet LTC1624 (Analog Devices)
| Hersteller | Analog Devices |
| Beschreibung | High Efficiency SO-8 N-Channel Switching Regulator Controller |
| Seiten / Seite | 28 / 1 — FEATURES. DESCRIPTION. Wide VIN Range: 3.5V to 36V Operation. Wide VOUT … |
| Dateiformat / Größe | PDF / 413 Kb |
| Dokumentensprache | Englisch |
FEATURES. DESCRIPTION. Wide VIN Range: 3.5V to 36V Operation. Wide VOUT Range: 1.19V to 30V in Step-Down. Configuration
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LTC1624 High Efficiency SO-8 N-Channel Switching Regulator Controller
U FEATURES DESCRIPTION
■ N-Channel MOSFET Drive The LTC®1624 is a current mode switching regulator ■ Implements Boost, Step-Down, SEPIC controller that drives an external N-channel power MOSFET and Inverting Regulators using a fixed frequency architecture. It can be operated in ■
Wide VIN Range: 3.5V to 36V Operation
all standard switching configurations including boost, ■
Wide VOUT Range: 1.19V to 30V in Step-Down
step-down, inverting and SEPIC. Burst ModeTM operation
Configuration
provides high efficiency at low load currents. A maximum ■ ±
1% 1.19V Reference
high duty cycle limit of 95% provides low dropout operation ■
Low Dropout Operation: 95% Duty Cycle
which extends operating time in battery-operated systems. ■ 200kHz Fixed Frequency The operating frequency is internally set to 200kHz, allowing ■ Low Standby Current small inductor values and minimizing PC board space. The ■ Very High Efficiency operating current level is user-programmable via an external ■ Remote Output Voltage Sense current sense resistor. Wide input supply range allows ■ Logic-Controlled Micropower Shutdown operation from 3.5V to 36V (absolute maximum). ■ Internal Diode for Bootstrapped Gate Drive ■ Current Mode Operation for Excellent Line and A multifunction pin (ITH / RUN) allows external Load Transient Response compensation for optimum load step response plus ■ Available in an 8-Lead SO Package shutdown. Soft start can also be implemented with the ITH/RUN pin to properly sequence supplies.
U APPLICATIONS
■ Notebook and Palmtop Computers, PDAs ■ Cellular Telephones and Wireless Modems ■ Battery-Operated Digital Devices ■ DC Power Distribution Systems , LTC and LT are registered trademarks of Linear Technology Corporation. ■ Battery Chargers Burst Mode is a trademark of Linear Technology Corporation.
U TYPICAL APPLICATION
VIN 4.8V TO 28V 1000pF SENSE– VIN + CIN RSENSE 22µF 0.05Ω 35V ITH/RUN BOOST C × 2 C M1 470pF LTC1624 Si4412DY V R FB TG C C L1 6.8k 100pF B 0.1µF 10µH VOUT GND SW 3.3V D1 2A MBRS340T3 R2 35.7k + COUT 100µF R1 10V 20k × 2
Figure 1. High Efficiency Step-Down Converter
1624 F01 1
U FEATURES DESCRIPTION
■ N-Channel MOSFET Drive The LTC®1624 is a current mode switching regulator ■ Implements Boost, Step-Down, SEPIC controller that drives an external N-channel power MOSFET and Inverting Regulators using a fixed frequency architecture. It can be operated in ■
Wide VIN Range: 3.5V to 36V Operation
all standard switching configurations including boost, ■
Wide VOUT Range: 1.19V to 30V in Step-Down
step-down, inverting and SEPIC. Burst ModeTM operation
Configuration
provides high efficiency at low load currents. A maximum ■ ±
1% 1.19V Reference
high duty cycle limit of 95% provides low dropout operation ■
Low Dropout Operation: 95% Duty Cycle
which extends operating time in battery-operated systems. ■ 200kHz Fixed Frequency The operating frequency is internally set to 200kHz, allowing ■ Low Standby Current small inductor values and minimizing PC board space. The ■ Very High Efficiency operating current level is user-programmable via an external ■ Remote Output Voltage Sense current sense resistor. Wide input supply range allows ■ Logic-Controlled Micropower Shutdown operation from 3.5V to 36V (absolute maximum). ■ Internal Diode for Bootstrapped Gate Drive ■ Current Mode Operation for Excellent Line and A multifunction pin (ITH / RUN) allows external Load Transient Response compensation for optimum load step response plus ■ Available in an 8-Lead SO Package shutdown. Soft start can also be implemented with the ITH/RUN pin to properly sequence supplies.
U APPLICATIONS
■ Notebook and Palmtop Computers, PDAs ■ Cellular Telephones and Wireless Modems ■ Battery-Operated Digital Devices ■ DC Power Distribution Systems , LTC and LT are registered trademarks of Linear Technology Corporation. ■ Battery Chargers Burst Mode is a trademark of Linear Technology Corporation.
U TYPICAL APPLICATION
VIN 4.8V TO 28V 1000pF SENSE– VIN + CIN RSENSE 22µF 0.05Ω 35V ITH/RUN BOOST C × 2 C M1 470pF LTC1624 Si4412DY V R FB TG C C L1 6.8k 100pF B 0.1µF 10µH VOUT GND SW 3.3V D1 2A MBRS340T3 R2 35.7k + COUT 100µF R1 10V 20k × 2
Figure 1. High Efficiency Step-Down Converter
1624 F01 1