LTC3891
RECOMMENDED FOR NEW DESIGNSLow IQ, 60V Synchronous Step-Down Controller
- Part Models
- 16
- 1ku List Price
- Starting From $5.25
Overview
- Wide VIN Range: 4V to 60V (65V Abs Max)
- Low Operating IQ: 50μA
- Wide Output Voltage Range: 0.8V ≤ VOUT ≤ 24V
- RSENSE or DCR Current Sensing
- Phase-Lockable Frequency (75kHz to 750kHz)
- Programmable Fixed Frequency (50kHz to 900kHz)
- Selectable Continuous, Pulse-Skipping or Low Ripple Burst Mode® Operation at Light Load
- Selectable Current Limit
- Very Low Dropout Operation: 99% Duty Cycle
- Adjustable Output Voltage Soft-Start or Tracking
- Power Good Output Voltage Monitor
- Output Overvoltage Protection
- Low Shutdown IQ: < 14μA
- Internal LDO Powers Gate Drive from VIN or EXTVCC
- No Current Foldback During Start-Up
- Small 20-Pin 3mm × 4mm QFN and TSSOP Packages
The LTC3891 is a high performance step-down switching regulator DC/DC controller that drives an all N-channel synchronous power MOSFET stage. A constant frequency current mode architecture allows a phase-lockable frequency of up to 750kHz.
The 50μA no-load quiescent current extends operating run time in battery-powered systems. OPTI-LOOP® compensation allows the transient response to be optimized over a wide range of output capacitance and ESR values. The LTC3891 features a precision 0.8V reference and power good output indicator. A wide 4V to 60V input supply range encompasses a wide range of intermediate bus voltages and battery chemistries. The output voltage of the LTC3891 can be programmed between 0.8V to 24V.
The TRACK/SS pin ramps the output voltages during start-up. Current foldback limits MOSFET heat dissipation during short-circuit conditions. The PLLIN/MODE pin selects among Burst Mode operation, pulse-skipping mode, or continuous conduction mode at light loads.
Applications
- Automotive Always-On Systems
- Battery Powered Digital Devices
- Distributed DC Power Systems
Documentation
Data Sheet 1
User Guide 2
Design Note 2
Technical Articles 2
Rarely Asked Question 1
Analog Dialogue 1
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal. View our quality and reliability program and certifications for more information.
| Part Model | Pin/Package Drawing | Documentation | CAD Symbols, Footprints, and 3D Models |
|---|---|---|---|
| LTC3891EFE#PBF | 20-Lead TSSOP w/ EP | ||
| LTC3891EFE#TRPBF | 20-Lead TSSOP w/ EP | ||
| LTC3891EUDC#PBF | 20-Lead QFN (3mm x 4mm x 0.75mm w/ EP) | ||
| LTC3891EUDC#TRPBF | 20-Lead QFN (3mm x 4mm x 0.75mm w/ EP) | ||
| LTC3891HFE#PBF | 20-Lead TSSOP w/ EP | ||
| LTC3891HFE#TRPBF | 20-Lead TSSOP w/ EP | ||
| LTC3891HUDC#PBF | 20-Lead QFN (3mm x 4mm x 0.75mm w/ EP) | ||
| LTC3891HUDC#TRPBF | 20-Lead QFN (3mm x 4mm x 0.75mm w/ EP) | ||
| LTC3891IFE#PBF | 20-Lead TSSOP w/ EP | ||
| LTC3891IFE#TRPBF | 20-Lead TSSOP w/ EP | ||
| LTC3891IUDC#PBF | 20-Lead QFN (3mm x 4mm x 0.75mm w/ EP) | ||
| LTC3891IUDC#TRPBF | 20-Lead QFN (3mm x 4mm x 0.75mm w/ EP) | ||
| LTC3891MPFE#PBF | 20-Lead TSSOP w/ EP | ||
| LTC3891MPFE#TRPBF | 20-Lead TSSOP w/ EP | ||
| LTC3891MPUDC#PBF | 20-Lead QFN (3mm x 4mm x 0.75mm w/ EP) | ||
| LTC3891MPUDC#TRPBF | 20-Lead QFN (3mm x 4mm x 0.75mm w/ EP) |
| Part Models | Product Lifecycle | PCN |
|---|---|---|
|
Apr 6, 2022 - 22_0068 Laser Top Mark for ETSSOP and TSSOP Packages Assembled in ADPG [PNG] and UTL |
||
| LTC3891EFE#PBF | PRODUCTION | |
| LTC3891EFE#TRPBF | PRODUCTION | |
| LTC3891HFE#PBF | PRODUCTION | |
| LTC3891HFE#TRPBF | PRODUCTION | |
| LTC3891IFE#PBF | PRODUCTION | |
| LTC3891IFE#TRPBF | PRODUCTION | |
| LTC3891MPFE#PBF | PRODUCTION | |
| LTC3891MPFE#TRPBF | PRODUCTION | |
|
Jul 31, 2020 - 20_0245 Notification of Wafer Fab Location Change for 0.6µm BICMOS Process Devices from ADI Milpitas (Hillview) to Vanguard Int. (Taiwan) |
||
| LTC3891EFE#PBF | PRODUCTION | |
| LTC3891EFE#TRPBF | PRODUCTION | |
| LTC3891EUDC#PBF | PRODUCTION | |
| LTC3891EUDC#TRPBF | PRODUCTION | |
| LTC3891HFE#PBF | PRODUCTION | |
| LTC3891HFE#TRPBF | PRODUCTION | |
| LTC3891HUDC#PBF | PRODUCTION | |
| LTC3891HUDC#TRPBF | PRODUCTION | |
| LTC3891IFE#PBF | PRODUCTION | |
| LTC3891IFE#TRPBF | PRODUCTION | |
| LTC3891IUDC#PBF | PRODUCTION | |
| LTC3891IUDC#TRPBF | PRODUCTION | |
| LTC3891MPFE#PBF | PRODUCTION | |
| LTC3891MPFE#TRPBF | PRODUCTION | |
| LTC3891MPUDC#PBF | PRODUCTION | |
| LTC3891MPUDC#TRPBF | PRODUCTION | |
|
Apr 14, 2025 - 25_0017 Bond Wire Change from Gold to Copper |
||
| LTC3891HFE#PBF | PRODUCTION | |
| LTC3891HFE#TRPBF | PRODUCTION | |
| LTC3891HUDC#PBF | PRODUCTION | |
| LTC3891HUDC#TRPBF | PRODUCTION | |
This is the most up-to-date revision of the Data Sheet.
Software Resources
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Request a Driver/SoftwareHardware Ecosystem
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Tools & Simulations
LTspice 4
- LTC3891 Demo Circuit - Low Iq, High Voltage Step-Down Converter (4.5-60V to 12V @ 15A)
- LTC3891 Demo Circuit - High Efficiency Positive to Negative Converter (12-36V to -12V @ 10A)
- LTC4000/LTC3891 Demo Circuit - High Voltage High Current Step-Down Converter, Power Path Controller & Li-Ion Battery Charger (24-60V to 16.8V @ 6.0A)
- LTC3891 Demo Circuit - High Voltage Synchronous Step-Down Converter with Low IQ (4.5V to 60V to 3.3V @ 5A)
Models for the following parts are available in LTspice:
- LTC3891
LTpowerCAD 4
- LTC3891 Project - Low Iq, Synchronous Step-Down Supply with Inductor DCR Current Sensing (16-55V to 12V @ 15A)
- LTC3891 Project - Low Iq, Synchronous Step-Down Supply with Inductor DCR Current Sensing (4.5-60V to 3.3V @ 5A)
- LTC3891 Project - Low Iq, Synchronous Step-Down Supply with Rsense Current Sensing (16-55V to 12V @ 15A)
- LTC3891 Project - Low Iq, Synchronous Step-Down Supply with Rsense Current Sensing (4.5-60V to 3.3V @ 5A)
Design tools for the following parts are available in LTpowerCAD:
- LTC3891
LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.
LTpowerCAD® is a power supply design program which selects power stage components, provides detailed power efficiency, shows quick loop Bode plot stability and load transient analysis, and can export to LTspice for simulation.
