Datasheet LTC3727LX-1 (Analog Devices)
| Manufacturer | Analog Devices |
| Description | High Efficiency, 2-Phase Synchronous Step-Down Switching Regulator |
| Pages / Page | 28 / 1 — FEATURES. DESCRIPTIO. Wide Output Voltage Range: 0.8V. VOUT. 14V. … |
| File Format / Size | PDF / 431 Kb |
| Document Language | English |
FEATURES. DESCRIPTIO. Wide Output Voltage Range: 0.8V. VOUT. 14V. Out-of-Phase Controllers Reduce Required Input
Model Line for this Datasheet
Text Version of Document
LTC3727LX-1 High Efficiency, 2-Phase Synchronous Step-Down Switching Regulator
U FEATURES DESCRIPTIO
■
Wide Output Voltage Range: 0.8V
≤
VOUT
≤
14V
The LTC®3727LX-1 is a high performance dual step-down ■
Out-of-Phase Controllers Reduce Required Input
switching regulator controller that drives all N-channel
Capacitance and Power Supply Induced Noise
synchronous power MOSFET stages. A constant-frequency ■
OPTI-LOOP® Compensation Minimizes COUT
current mode architecture allows phase-lockable frequency ■ ±
1.5% Output Voltage Accuracy
of up to 550kHz. Power loss and noise due to the ESR of ■
Power Good Output Voltage Monitor
the input capacitors are minimized by operating the two ■
Phase-Lockable Fixed Frequency 250kHz to 550kHz
controller output stages out of phase. ■ Dual N-Channel MOSFET Synchronous Drive OPTI-LOOP compensation allows the transient response ■ Wide VIN Range: 4V to 32V Operation to be optimized over a wide range of output capacitance and ■ Very Low Dropout Operation: 99% Duty Cycle ESR values. There is a precision 0.8V reference and a power ■ Adjustable Soft-Start Current Ramping good output indicator. A wide 4V to 28V (32V maximum) ■ Foldback Output Current Limiting input supply range encompasses all battery chemistries. ■ Output Overvoltage Protection ■ Low Shutdown I
Table 1
Q: 20µA ■ Selectable Constant-Frequency or Burst Mode®
PART VIN VREF ACCURACY LATCH- MINIMUM
Operation
NUMBER RANGE OVERTEMPERATURE OFF ON-TIME
■ Small 28-Lead SSOP and 5mm × 5mm QFN Packages LTC3727LX-1 4V to 32V ±1.5% No 120ns LTC3727 4V to 36V ±1% Yes 180ns
U
LTC3727-1 4V to 36V ±1% No 180ns
APPLICATIO S
LTC3727A-1 4V to 36V ±1% No 120ns ■ Telecom Systems , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. Burst ■ Automotive Systems Mode and OPTI-LOOP are registered trademarks of Linear Technology Corporation. All other ■ Distributed DC Power Systems trademarks are the property of their respective owners. Protected by U.S. Patents, including 5481178, 5929620, 6177787, 6144194, 6100678, 5408150, 6580258, 6304066, 5705919.
U TYPICAL APPLICATIO
VIN + 18V TO 28V 22µF 1µF 4.7µF 50V CERAMIC V CERAMIC IN PGOOD INTVCC M1 TG1 TG2 M3 0.1µF BOOST1 BOOST2 0.1µF 8µH 15µH SW1 SW2 LTC3727LX-1 M2 BG1 BG2 M4 PLLIN PGND SENSE1+ SENSE2+ 1000pF 0.015Ω 1000pF 0.015Ω SENSE1– SENSE2– VOUT1 VOUT2 5V VOSENSE1 VOSENSE2 12V 5A 105k 280k 4A 1% ITH1 ITH2 1% + 220pF + 56µF 47µF 220pF RUN/SS1 SGND RUN/SS2 20k 20k 15V 6V 1% 1% SP SP 15k 15k 0.1µF 0.1µF M1, M2, M3, M4: FDS6680A 3727LX1 F01
Figure 1. High Efficiency Dual 12V/5V Step-Down Converter
3727lx1fa 1
U FEATURES DESCRIPTIO
■
Wide Output Voltage Range: 0.8V
≤
VOUT
≤
14V
The LTC®3727LX-1 is a high performance dual step-down ■
Out-of-Phase Controllers Reduce Required Input
switching regulator controller that drives all N-channel
Capacitance and Power Supply Induced Noise
synchronous power MOSFET stages. A constant-frequency ■
OPTI-LOOP® Compensation Minimizes COUT
current mode architecture allows phase-lockable frequency ■ ±
1.5% Output Voltage Accuracy
of up to 550kHz. Power loss and noise due to the ESR of ■
Power Good Output Voltage Monitor
the input capacitors are minimized by operating the two ■
Phase-Lockable Fixed Frequency 250kHz to 550kHz
controller output stages out of phase. ■ Dual N-Channel MOSFET Synchronous Drive OPTI-LOOP compensation allows the transient response ■ Wide VIN Range: 4V to 32V Operation to be optimized over a wide range of output capacitance and ■ Very Low Dropout Operation: 99% Duty Cycle ESR values. There is a precision 0.8V reference and a power ■ Adjustable Soft-Start Current Ramping good output indicator. A wide 4V to 28V (32V maximum) ■ Foldback Output Current Limiting input supply range encompasses all battery chemistries. ■ Output Overvoltage Protection ■ Low Shutdown I
Table 1
Q: 20µA ■ Selectable Constant-Frequency or Burst Mode®
PART VIN VREF ACCURACY LATCH- MINIMUM
Operation
NUMBER RANGE OVERTEMPERATURE OFF ON-TIME
■ Small 28-Lead SSOP and 5mm × 5mm QFN Packages LTC3727LX-1 4V to 32V ±1.5% No 120ns LTC3727 4V to 36V ±1% Yes 180ns
U
LTC3727-1 4V to 36V ±1% No 180ns
APPLICATIO S
LTC3727A-1 4V to 36V ±1% No 120ns ■ Telecom Systems , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. Burst ■ Automotive Systems Mode and OPTI-LOOP are registered trademarks of Linear Technology Corporation. All other ■ Distributed DC Power Systems trademarks are the property of their respective owners. Protected by U.S. Patents, including 5481178, 5929620, 6177787, 6144194, 6100678, 5408150, 6580258, 6304066, 5705919.
U TYPICAL APPLICATIO
VIN + 18V TO 28V 22µF 1µF 4.7µF 50V CERAMIC V CERAMIC IN PGOOD INTVCC M1 TG1 TG2 M3 0.1µF BOOST1 BOOST2 0.1µF 8µH 15µH SW1 SW2 LTC3727LX-1 M2 BG1 BG2 M4 PLLIN PGND SENSE1+ SENSE2+ 1000pF 0.015Ω 1000pF 0.015Ω SENSE1– SENSE2– VOUT1 VOUT2 5V VOSENSE1 VOSENSE2 12V 5A 105k 280k 4A 1% ITH1 ITH2 1% + 220pF + 56µF 47µF 220pF RUN/SS1 SGND RUN/SS2 20k 20k 15V 6V 1% 1% SP SP 15k 15k 0.1µF 0.1µF M1, M2, M3, M4: FDS6680A 3727LX1 F01
Figure 1. High Efficiency Dual 12V/5V Step-Down Converter
3727lx1fa 1
