Datasheet LTC3890-1 (Analog Devices)
| Manufacturer | Analog Devices |
| Description | 60V Low IQ, Dual, 2-Phase Synchronous Step-Down DC/DC Controller |
| Pages / Page | 36 / 1 — FEATURES. DESCRIPTION. Wide VIN Range: 4V to 60V (65V Abs Max). Low … |
| File Format / Size | PDF / 898 Kb |
| Document Language | English |
FEATURES. DESCRIPTION. Wide VIN Range: 4V to 60V (65V Abs Max). Low Operating IQ: 50µA (One Channel On)
Model Line for this Datasheet
Text Version of Document
LTC3890-1 60V Low IQ, Dual, 2-Phase Synchronous Step-Down DC/DC Controller
FEATURES DESCRIPTION
n
Wide VIN Range: 4V to 60V (65V Abs Max)
The LTC®3890-1 is a high performance dual step-down n
Low Operating IQ: 50µA (One Channel On)
switching regulator DC/DC controller that drives all n
Wide Output Voltage Range: 0.8V ≤ VOUT ≤ 24V
N-channel synchronous power MOSFET stages. A constant n
RSENSE or DCR Current Sensing
frequency current mode architecture allows a phase- n Out-of-Phase Controllers Reduce Required Input lockable frequency of up to 850kHz. Power loss and supply Capacitance and Power Supply Induced Noise noise are minimized by operating the two controller output n Phase-Lockable Frequency (75kHz to 850kHz) stages out-of-phase. n Programmable Fixed Frequency (50kHz to 900kHz) The 50μA no-load quiescent current extends operating life n Selectable Continuous, Pulse-Skipping or Low Ripple in battery-powered systems. OPTI-LOOP® compensation Burst Mode® Operation at Light Loads allows the transient response to be optimized over a wide n Very Low Dropout Operation: 99% Duty Cycle range of output capacitance and ESR values. A wide 4V n Adjustable Output Voltage Soft-Start or Tracking to 60V input supply range encompasses a wide range of n Power Good Output Voltage Monitor intermediate bus voltages and battery chemistries. n Output Overvoltage Protection Independent TRACK/SS pins for each controller ramp the n Low Shutdown IQ: <14µA output voltages during start-up. Current foldback limits n Internal LDO Powers Gate Drive from VIN or EXTVCC MOSFET heat dissipation during short-circuit conditions. n No Current Foldback During Start-Up The PLLIN/MODE pin selects among Burst Mode operation, n Narrow SSOP Package pulse-skipping mode, or continuous conduction mode at light loads.
APPLICATIONS
For a leadless 32-pin QFN package with additional features n Automotive Always-On Systems of adjustable current limit, clock out, phase modulation n Battery Operated Digital Devices and two PGOOD outputs, see the LTC3890 data sheet. n Distributed DC Power Systems L, LT, LTC, LTM, Linear Technology, Burst Mode, OPTI-LOOP and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents including 5481178, 5705919, 5929620, 6100678, 6144194, 6177787, 6304066, 6580258, 7230497.
TYPICAL APPLICATION High Efficiency Dual 8.5V/3.3V Output Step-Down Converter Efficiency and Power Loss
VIN
vs Output Current
9V TO 60V 4.7µF 22µF 100 10000 V V IN = 12V IN INTVCC 90 VOUT = 3.3V TG1 TG2 0.1µF 0.1µF 80 1000 4.7µH BOOST1 BOOST2 8µH POWER LOSS (mW) 70 SW1 SW2 60 100 BG1 BG2 LTC3890-1 50 PGND 40 10 SENSE1+ EFFICIENCY (%) SENSE2+ 30 0.008Ω 0.01Ω 20 1 V SENSE1– SENSE2– V OUT1 OUT2 10 3.3V 8.5V VFB1 VFB2 0 0.1 5A 100k ITH1 ITH2 100k 3A 0.0001 0.001 0.01 0.1 1 10 470µF 1000pF 1000pF TRACK/SS1 SGND TRACK/SS2 330µF 10.5k OUTPUT CURRENT (A) 31.6k 34.8k 34.8k 38901 TA01b 0.1µF 0.1µF 38901 TA01a 38901fb 1 Document Outline Features Description Applications Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Functional Diagram Operation Applications Information Typical Applications Package Description Revision History Typical Application Related Parts
FEATURES DESCRIPTION
n
Wide VIN Range: 4V to 60V (65V Abs Max)
The LTC®3890-1 is a high performance dual step-down n
Low Operating IQ: 50µA (One Channel On)
switching regulator DC/DC controller that drives all n
Wide Output Voltage Range: 0.8V ≤ VOUT ≤ 24V
N-channel synchronous power MOSFET stages. A constant n
RSENSE or DCR Current Sensing
frequency current mode architecture allows a phase- n Out-of-Phase Controllers Reduce Required Input lockable frequency of up to 850kHz. Power loss and supply Capacitance and Power Supply Induced Noise noise are minimized by operating the two controller output n Phase-Lockable Frequency (75kHz to 850kHz) stages out-of-phase. n Programmable Fixed Frequency (50kHz to 900kHz) The 50μA no-load quiescent current extends operating life n Selectable Continuous, Pulse-Skipping or Low Ripple in battery-powered systems. OPTI-LOOP® compensation Burst Mode® Operation at Light Loads allows the transient response to be optimized over a wide n Very Low Dropout Operation: 99% Duty Cycle range of output capacitance and ESR values. A wide 4V n Adjustable Output Voltage Soft-Start or Tracking to 60V input supply range encompasses a wide range of n Power Good Output Voltage Monitor intermediate bus voltages and battery chemistries. n Output Overvoltage Protection Independent TRACK/SS pins for each controller ramp the n Low Shutdown IQ: <14µA output voltages during start-up. Current foldback limits n Internal LDO Powers Gate Drive from VIN or EXTVCC MOSFET heat dissipation during short-circuit conditions. n No Current Foldback During Start-Up The PLLIN/MODE pin selects among Burst Mode operation, n Narrow SSOP Package pulse-skipping mode, or continuous conduction mode at light loads.
APPLICATIONS
For a leadless 32-pin QFN package with additional features n Automotive Always-On Systems of adjustable current limit, clock out, phase modulation n Battery Operated Digital Devices and two PGOOD outputs, see the LTC3890 data sheet. n Distributed DC Power Systems L, LT, LTC, LTM, Linear Technology, Burst Mode, OPTI-LOOP and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents including 5481178, 5705919, 5929620, 6100678, 6144194, 6177787, 6304066, 6580258, 7230497.
TYPICAL APPLICATION High Efficiency Dual 8.5V/3.3V Output Step-Down Converter Efficiency and Power Loss
VIN
vs Output Current
9V TO 60V 4.7µF 22µF 100 10000 V V IN = 12V IN INTVCC 90 VOUT = 3.3V TG1 TG2 0.1µF 0.1µF 80 1000 4.7µH BOOST1 BOOST2 8µH POWER LOSS (mW) 70 SW1 SW2 60 100 BG1 BG2 LTC3890-1 50 PGND 40 10 SENSE1+ EFFICIENCY (%) SENSE2+ 30 0.008Ω 0.01Ω 20 1 V SENSE1– SENSE2– V OUT1 OUT2 10 3.3V 8.5V VFB1 VFB2 0 0.1 5A 100k ITH1 ITH2 100k 3A 0.0001 0.001 0.01 0.1 1 10 470µF 1000pF 1000pF TRACK/SS1 SGND TRACK/SS2 330µF 10.5k OUTPUT CURRENT (A) 31.6k 34.8k 34.8k 38901 TA01b 0.1µF 0.1µF 38901 TA01a 38901fb 1 Document Outline Features Description Applications Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Functional Diagram Operation Applications Information Typical Applications Package Description Revision History Typical Application Related Parts
