Datasheet LTC3713 (Analog Devices)
| Fabricante | Analog Devices |
| Descripción | Low Input Voltage, High Power, No RSENSE Synchronous Buck DC/DC Controller |
| Páginas / Página | 24 / 1 — FEATURES. DESCRIPTIO. Very Low VIN(MIN): 1.5V. True Current Mode Control. … |
| Formato / tamaño de archivo | PDF / 291 Kb |
| Idioma del documento | Inglés |
FEATURES. DESCRIPTIO. Very Low VIN(MIN): 1.5V. True Current Mode Control. 5V Drive for N-Channel MOSFETs Eliminates
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LTC3713 Low Input Voltage, High Power, No R TM SENSE Synchronous Buck DC/DC Controller
U FEATURES DESCRIPTIO
■
Very Low VIN(MIN): 1.5V
The LTC®3713 is a high current, high efficiency synchro- ■
True Current Mode Control
nous buck switching regulator controller optimized for ■
5V Drive for N-Channel MOSFETs Eliminates
use with very low input supply voltages. It operates from
Auxillary 5V Supply
inputs as low as 1.5V and provides a regulated output ■
No Sense Resistor Required
voltage from 0.8V up to (0.9)VIN. The controller uses ■
Uses Standard 5V Logic-Level N-Channel MOSFETs
a valley current control architecture to enable high operat- ■ Adjustable Current Limit ing frequencies without requiring a sense resistor. ■ Adjustable Frequency Operating frequency is selected by an external resistor and ■ Switch tON(MIN) < 100ns is compensated for variations in VIN and VOUT. The LTC3713 ■ 2% to 90% Duty Cycle at 200kHz uses a pair of standard 5V logic-level N-channel external ■ 0.8V ±1% Reference MOSFETs, eliminating the need for expensive P-channel ■ Power Good Output Voltage Monitor or low threshold devices. ■ Programmable Soft-Start Discontinuous mode operation provides high efficiency ■ Output Overvoltage Protection operation at light loads. A forced continuous control ■ Optional Short-Circuit Shutdown Timer pin reduces noise and RF interference, and can assist ■ Small 24-Lead SSOP Package
U
secondary winding regulation by disabling discontinuous
APPLICATIO S
operation when the main output is lightly loaded. Fault protection is provided by internal foldback current limit- ■ Telecom Card 3.3V, 2.5V, 1.8V Step-Down ing, an output overvoltage comparator and an optional ■ Bus Termination (DDR memory, SSTL) short-circuit shutdown timer. ■ Synchronous Buck with General Purpose Boost , LTC and LT are registered trademarks of Linear Technology Corporation. ■ Low VIN Synchronous Boost No RSENSE is a trademark of Linear Technology Corporation.
U TYPICAL APPLICATIO
VIN 1.8V TO 3.3V CMDSH-3 22µF SHDN BOOST ×2
Efficiency vs Load Current
330k 0.33µF 100 5.6k I TG M1 VIN = 2.5V ON L1 90 LTC3713 1.8µH VOUT A V SW1 80 FB1 1.25V + B C 10A SENSE+ OUT 70 10k 270µF 680pF BG M2 ×2 60 20k B340A ITH PGND 50 SENSE– 40 10µF EFFICIENCY (%) RUN/SS INTVCC 30 0.1µF PGOOD VIN1 20 SGND V 3713 F01a IN2 10 4.7µF MBR0520 COUT: PANASONIC EEFUEOD271R 0 4.7µH L1: (A) PANASONIC ETQP6FIR8BFA 0.01 0.04 0.10 0.40 1 3 7 12 15 (B) TOKO D104C-1.8µH LOAD CURRENT (A) VFB2 SW2 M1, M2: (A) IRF7822, (B) IRF7811A 12.1k 37.4k 3713 F01b
Figure 1. High Efficiency Step-Down Converter from 1.8V to 3.3V Input
3713fa 1
U FEATURES DESCRIPTIO
■
Very Low VIN(MIN): 1.5V
The LTC®3713 is a high current, high efficiency synchro- ■
True Current Mode Control
nous buck switching regulator controller optimized for ■
5V Drive for N-Channel MOSFETs Eliminates
use with very low input supply voltages. It operates from
Auxillary 5V Supply
inputs as low as 1.5V and provides a regulated output ■
No Sense Resistor Required
voltage from 0.8V up to (0.9)VIN. The controller uses ■
Uses Standard 5V Logic-Level N-Channel MOSFETs
a valley current control architecture to enable high operat- ■ Adjustable Current Limit ing frequencies without requiring a sense resistor. ■ Adjustable Frequency Operating frequency is selected by an external resistor and ■ Switch tON(MIN) < 100ns is compensated for variations in VIN and VOUT. The LTC3713 ■ 2% to 90% Duty Cycle at 200kHz uses a pair of standard 5V logic-level N-channel external ■ 0.8V ±1% Reference MOSFETs, eliminating the need for expensive P-channel ■ Power Good Output Voltage Monitor or low threshold devices. ■ Programmable Soft-Start Discontinuous mode operation provides high efficiency ■ Output Overvoltage Protection operation at light loads. A forced continuous control ■ Optional Short-Circuit Shutdown Timer pin reduces noise and RF interference, and can assist ■ Small 24-Lead SSOP Package
U
secondary winding regulation by disabling discontinuous
APPLICATIO S
operation when the main output is lightly loaded. Fault protection is provided by internal foldback current limit- ■ Telecom Card 3.3V, 2.5V, 1.8V Step-Down ing, an output overvoltage comparator and an optional ■ Bus Termination (DDR memory, SSTL) short-circuit shutdown timer. ■ Synchronous Buck with General Purpose Boost , LTC and LT are registered trademarks of Linear Technology Corporation. ■ Low VIN Synchronous Boost No RSENSE is a trademark of Linear Technology Corporation.
U TYPICAL APPLICATIO
VIN 1.8V TO 3.3V CMDSH-3 22µF SHDN BOOST ×2
Efficiency vs Load Current
330k 0.33µF 100 5.6k I TG M1 VIN = 2.5V ON L1 90 LTC3713 1.8µH VOUT A V SW1 80 FB1 1.25V + B C 10A SENSE+ OUT 70 10k 270µF 680pF BG M2 ×2 60 20k B340A ITH PGND 50 SENSE– 40 10µF EFFICIENCY (%) RUN/SS INTVCC 30 0.1µF PGOOD VIN1 20 SGND V 3713 F01a IN2 10 4.7µF MBR0520 COUT: PANASONIC EEFUEOD271R 0 4.7µH L1: (A) PANASONIC ETQP6FIR8BFA 0.01 0.04 0.10 0.40 1 3 7 12 15 (B) TOKO D104C-1.8µH LOAD CURRENT (A) VFB2 SW2 M1, M2: (A) IRF7822, (B) IRF7811A 12.1k 37.4k 3713 F01b
Figure 1. High Efficiency Step-Down Converter from 1.8V to 3.3V Input
3713fa 1