Datasheet LTC3835-1 (Analog Devices)
| Hersteller | Analog Devices |
| Beschreibung | Low IQ Synchronous Step-Down Controller |
| Seiten / Seite | 28 / 1 — FEATURES. DESCRIPTION. Wide Output Voltage Range: 0.8V ≤ VOUT ≤ 10V. Low … |
| Dateiformat / Größe | PDF / 299 Kb |
| Dokumentensprache | Englisch |
FEATURES. DESCRIPTION. Wide Output Voltage Range: 0.8V ≤ VOUT ≤ 10V. Low Operating IQ: 80μA. OPTI-LOOP
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LTC3835-1 Low IQ Synchronous Step-Down Controller
FEATURES DESCRIPTION
n
Wide Output Voltage Range: 0.8V ≤ VOUT ≤ 10V
The LTC®3835-1 is a high performance step-down switch- n
Low Operating IQ: 80μA
ing regulator controller that drives an all N-channel synchro- n
OPTI-LOOP
®
Compensation Minimizes COUT
nous power MOSFET stage. A constant-frequency current n
±1% Output Voltage Accuracy
mode architecture allows a phase-lockable frequency of n
Wide VIN Range: 4V to 36V Operation
up to 650kHz. n
Phase-Lockable Fixed Frequency 140kHz to 650kHz
The 80μA no-load quiescent current extends operating n Dual N-Channel MOSFET Synchronous Drive life in battery powered systems. OPTI-LOOP compensa- n Very Low Dropout Operation: 99% Duty Cycle tion allows the transient response to be optimized over n Adjustable Output Voltage Soft-Start or Tracking a wide range of output capacitance and ESR values. The n Output Current Foldback Limiting LTC3835-1 features a precision 0.8V reference and a power n Output Overvoltage Protection good output indicator. The 4V to 36V input supply range n Low Shutdown IQ: 10μA encompasses a wide range of battery chemistries. n Selectable Continuous, Pulse-Skipping or Burst Mode® Operation at Light Loads The TRACK/SS pin ramps the output voltage during start- n Small 16-Lead Narrow SSOP or 3mm × 5mm up. Current foldback limits MOSFET heat dissipation during DFN Package short-circuit conditions.
Comparison of LTC3835 and LTC3835-1 APPLICATIONS CLKOUT/ PART # PHASMD EXTV
n
CC PGOOD PACKAGES
Automotive Systems LTC3835 YES YES YES FE20/4 × 5 QFN n Telecom Systems LTC3835-1 NO NO NO n GN16/3 × 5 DFN Battery-Operated Digital Devices L, LT, LTC, LTM, Burst Mode, and OPTI-LOOP are registered trademarks of Linear n Distributed DC Power Systems Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents, including 5408150, 5481178, 5705919, 5929620, 6304066, 6498466, 6580258, 6611131.
TYPICAL APPLICATION High Effi ciency Step-Down Converter Effi ciency and Power Loss
VIN PLLLPF VIN
vs Load Current
4V TO 36V 10μF 100 100000 0.01μF RUN TG VIN = 12V; VOUT = 3.3V TRACK/SS 0.22μF 90 EFFICIENCY 10000 BOOST 80 3.3μH 0.012Ω VOUT I POWER LOSS (mW) TH 70 SW 3.3V 330pF 1000 LTC3835-1 5A 60 100pF 33k 50 100 150μF SGND INTVCC 40 4.7μF EFFICIENCY (%) POWER LOSS 10 20k PLLIN/MODE 30 V 20 FB BG 1 10 SENSE– 62.5k 0 0.1 SENSE+ PGND 0.001 0.01 0.1 1 10 100 1000 10000 LOAD CURRENT (mA) 38351 TA01b 38351 TA01 38351fc 1
FEATURES DESCRIPTION
n
Wide Output Voltage Range: 0.8V ≤ VOUT ≤ 10V
The LTC®3835-1 is a high performance step-down switch- n
Low Operating IQ: 80μA
ing regulator controller that drives an all N-channel synchro- n
OPTI-LOOP
®
Compensation Minimizes COUT
nous power MOSFET stage. A constant-frequency current n
±1% Output Voltage Accuracy
mode architecture allows a phase-lockable frequency of n
Wide VIN Range: 4V to 36V Operation
up to 650kHz. n
Phase-Lockable Fixed Frequency 140kHz to 650kHz
The 80μA no-load quiescent current extends operating n Dual N-Channel MOSFET Synchronous Drive life in battery powered systems. OPTI-LOOP compensa- n Very Low Dropout Operation: 99% Duty Cycle tion allows the transient response to be optimized over n Adjustable Output Voltage Soft-Start or Tracking a wide range of output capacitance and ESR values. The n Output Current Foldback Limiting LTC3835-1 features a precision 0.8V reference and a power n Output Overvoltage Protection good output indicator. The 4V to 36V input supply range n Low Shutdown IQ: 10μA encompasses a wide range of battery chemistries. n Selectable Continuous, Pulse-Skipping or Burst Mode® Operation at Light Loads The TRACK/SS pin ramps the output voltage during start- n Small 16-Lead Narrow SSOP or 3mm × 5mm up. Current foldback limits MOSFET heat dissipation during DFN Package short-circuit conditions.
Comparison of LTC3835 and LTC3835-1 APPLICATIONS CLKOUT/ PART # PHASMD EXTV
n
CC PGOOD PACKAGES
Automotive Systems LTC3835 YES YES YES FE20/4 × 5 QFN n Telecom Systems LTC3835-1 NO NO NO n GN16/3 × 5 DFN Battery-Operated Digital Devices L, LT, LTC, LTM, Burst Mode, and OPTI-LOOP are registered trademarks of Linear n Distributed DC Power Systems Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents, including 5408150, 5481178, 5705919, 5929620, 6304066, 6498466, 6580258, 6611131.
TYPICAL APPLICATION High Effi ciency Step-Down Converter Effi ciency and Power Loss
VIN PLLLPF VIN
vs Load Current
4V TO 36V 10μF 100 100000 0.01μF RUN TG VIN = 12V; VOUT = 3.3V TRACK/SS 0.22μF 90 EFFICIENCY 10000 BOOST 80 3.3μH 0.012Ω VOUT I POWER LOSS (mW) TH 70 SW 3.3V 330pF 1000 LTC3835-1 5A 60 100pF 33k 50 100 150μF SGND INTVCC 40 4.7μF EFFICIENCY (%) POWER LOSS 10 20k PLLIN/MODE 30 V 20 FB BG 1 10 SENSE– 62.5k 0 0.1 SENSE+ PGND 0.001 0.01 0.1 1 10 100 1000 10000 LOAD CURRENT (mA) 38351 TA01b 38351 TA01 38351fc 1