Datasheet LTC3709 (Analog Devices)
| Hersteller | Analog Devices |
| Beschreibung | Fast 2-Phase, No RSENSE , Synchronous DC/DC Controller with Tracking/Sequencing |
| Seiten / Seite | 24 / 1 — FEATURES. DESCRIPTIO. PolyPhase® Valley Current Mode Controller. … |
| Dateiformat / Größe | PDF / 329 Kb |
| Dokumentensprache | Englisch |
FEATURES. DESCRIPTIO. PolyPhase® Valley Current Mode Controller. Synchronizable to an External Clock with PLL
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LTC3709 Fast 2-Phase, No R TM SENSE , Synchronous DC/DC Controller with Tracking/Sequencing
U FEATURES DESCRIPTIO
■
PolyPhase® Valley Current Mode Controller
The LTC®3709 is a single output, dual phase, synchronous ■
Synchronizable to an External Clock with PLL
step-down switching regulator. The controller uses a ■
Coincident or Ratiometric Tracking
constant on-time, valley current control architecture to ■
Sense Resistor Optional
deliver very low duty cycles without requiring a sense ■
2% to 90% Duty Cycle at 200kHz
resistor. Operating frequency is selected by an external ■
tON(MIN) < 100ns
resistor and is compensated for variations in input supply ■
True Remote Sensing Differential Amplifier
voltage. An internal phase-lock loop allows the LTC3709 ■ High Efficiency at Both Light and Heavy Loads to be synchronized to an external clock. ■ Power Good Output Voltage Monitor A TRACK pin is provided for tracking or sequencing the ■ 0.6V ±1% Reference output voltage among several LTC3709 chips or an ■ Adjustable Current Limit LTC3709 and other DC/DC regulators. Soft-start is ac- ■ Programmable Soft-Start and Operating Frequency complished using an external timing capacitor. ■ Output Overvoltage Protection ■ Optional Short-Circuit Shutdown Timer Fault protection is provided by an output overvoltage com- ■ Available in 32-Lead (5mm × 5mm) QFN and 36-Lead parator and an optional short-circuit shutdown timer. The SSOP Packages current limit level is user programmable. A wide supply range allows voltages as high as 31V to step down as low
U
as 0.6V.
APPLICATIO S
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. ■ Notebook Computers No RSENSE is a trademark of Linear Technology Corporation. PolyPhase is a registered trademark of Linear Technology Corporation. ■ Power Supply for DSP, ASIC, Graphic Processors All other trademarks are the property of their respective owners. Protected by U.S. Patents including 5481178, 6476589, 6144194, 5847554, 6100678, 6304066, 6580258, 6674274, 6462525, 6593724.
U TYPICAL APPLICATIO High Efficiency Dual Phase 1.5V/30A Step-Down Converter
5V 4.7µF 324k 10Ω VIN 4.5V TO 28V 10µF 1µF 35V 47.5k VCC DRVCC ION ×3 TRACK TG1 HAT2168H
Efficiency and Power Loss
VRNG 0.22µF FCB BOOST1 1.22 100 10 10k µH VIN = 12V 100k SW1 95 9 0.1µF PGOOD SENSE1+ 90 8 RUN/SS BG1 HAT2165H EFFICIENCY POWER LOSS (W) 85 7 3.32k EXTLPF SENSE1– 80 6 INTLPF PGND1 75 5 100nF I LTC3709 TH VIN 680pF 20k 70 4 SGND TG2 HAT2168H EFFICIENCY (%) 65 3 0.22µF 10k BOOST2 POWER LOSS 1.22µH V 60 2 OUT V SW2 1.5V FB 55 1 DIFFOUT SENSE2+ 30A 15k 50 0 BG2 HAT2165H 0.01 0.1 1 10 100 V – + 330µF OS LOAD CURRENT (A) SENSE2– + 2.5V VOS PGND2 × 3709 TA01b 4 3709 TA01a 3709fb 1
U FEATURES DESCRIPTIO
■
PolyPhase® Valley Current Mode Controller
The LTC®3709 is a single output, dual phase, synchronous ■
Synchronizable to an External Clock with PLL
step-down switching regulator. The controller uses a ■
Coincident or Ratiometric Tracking
constant on-time, valley current control architecture to ■
Sense Resistor Optional
deliver very low duty cycles without requiring a sense ■
2% to 90% Duty Cycle at 200kHz
resistor. Operating frequency is selected by an external ■
tON(MIN) < 100ns
resistor and is compensated for variations in input supply ■
True Remote Sensing Differential Amplifier
voltage. An internal phase-lock loop allows the LTC3709 ■ High Efficiency at Both Light and Heavy Loads to be synchronized to an external clock. ■ Power Good Output Voltage Monitor A TRACK pin is provided for tracking or sequencing the ■ 0.6V ±1% Reference output voltage among several LTC3709 chips or an ■ Adjustable Current Limit LTC3709 and other DC/DC regulators. Soft-start is ac- ■ Programmable Soft-Start and Operating Frequency complished using an external timing capacitor. ■ Output Overvoltage Protection ■ Optional Short-Circuit Shutdown Timer Fault protection is provided by an output overvoltage com- ■ Available in 32-Lead (5mm × 5mm) QFN and 36-Lead parator and an optional short-circuit shutdown timer. The SSOP Packages current limit level is user programmable. A wide supply range allows voltages as high as 31V to step down as low
U
as 0.6V.
APPLICATIO S
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. ■ Notebook Computers No RSENSE is a trademark of Linear Technology Corporation. PolyPhase is a registered trademark of Linear Technology Corporation. ■ Power Supply for DSP, ASIC, Graphic Processors All other trademarks are the property of their respective owners. Protected by U.S. Patents including 5481178, 6476589, 6144194, 5847554, 6100678, 6304066, 6580258, 6674274, 6462525, 6593724.
U TYPICAL APPLICATIO High Efficiency Dual Phase 1.5V/30A Step-Down Converter
5V 4.7µF 324k 10Ω VIN 4.5V TO 28V 10µF 1µF 35V 47.5k VCC DRVCC ION ×3 TRACK TG1 HAT2168H
Efficiency and Power Loss
VRNG 0.22µF FCB BOOST1 1.22 100 10 10k µH VIN = 12V 100k SW1 95 9 0.1µF PGOOD SENSE1+ 90 8 RUN/SS BG1 HAT2165H EFFICIENCY POWER LOSS (W) 85 7 3.32k EXTLPF SENSE1– 80 6 INTLPF PGND1 75 5 100nF I LTC3709 TH VIN 680pF 20k 70 4 SGND TG2 HAT2168H EFFICIENCY (%) 65 3 0.22µF 10k BOOST2 POWER LOSS 1.22µH V 60 2 OUT V SW2 1.5V FB 55 1 DIFFOUT SENSE2+ 30A 15k 50 0 BG2 HAT2165H 0.01 0.1 1 10 100 V – + 330µF OS LOAD CURRENT (A) SENSE2– + 2.5V VOS PGND2 × 3709 TA01b 4 3709 TA01a 3709fb 1