LTC3869
RECOMMENDED FOR NEW DESIGNSDual, 2-Phase Synchronous Step-Down DC/DC Controllers
- Part Models
- 10
- 1ku List Price
- Starting From $4.04
Overview
- Dual, 180° Phased Controllers Reduce Required Input Capacitance and Power Supply Induced Noise
- Accurate Multiphase Current Matching
- RSENSE or DCR Current Sensing
- ±0.75% 0.6V Output Voltage Accuracy
- Phase-Lockable Fixed Frequency 250kHz to 780kHz
- High Efficiency: Up to 95%
- Dual N-channel MOSFET Synchronous Drive
- Wide VIN Range: 4V to 38V (40V Max) Operation
- Wide VOUT Range: 0.6V to 12.5V Operation
- Adjustable Soft-Start Current Ramping or Tracking
- Foldback Output Current Limiting
- Output Overvoltage Protection
- Power Good Output Voltage Monitor
- 5V Low Dropout Regulator
- Small 28-Lead QFN and Narrow SSOP Packages
The LTC3869 is a high performance dual synchronous step-down switching regulator controller that drives all N-channel synchronous power MOSFET stages. A constant frequency current mode architecture allows a phase-lockable frequency of up to 780kHz. Power loss and noise due to the ESR of the input capacitors are minimized by operating the two controller output stages out-of-phase.
OPTI-LOOP® compensation allows the transient response to be optimized over a wide range of output capacitance and ESR values. A wide 4V to 38V input supply range encompasses most battery chemistries. Independent TK/SS pins for each controller ramp the output voltage during start-up. Current foldback limits MOSFET heat dissipation during short-circuit conditions. The MODE/PLLIN pin selects among Burst Mode® operation, pulse-skipping mode, or continuous inductor current mode and allows the IC to be synchronized to an external clock.
The LTC3869 is available in low profile 4mm × 4mm and 4mm × 5mm QFN packages. The LTC3869-2 is available in an SSOP-28 package. The LTC3869 is pin-compatible with the LTC3850.
Applications
- Server Systems
- Telecom Systems
- Industrial and Medical Instruments
- High Power Battery-Operated Devices
- DC Power Distribution Systems
Documentation
Data Sheet 1
User Guide 2
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 |
|---|---|---|---|
| LTC3869EUF#PBF | 28-Lead QFN (4mm x 4mm x 0.75mm w/ EP) | ||
| LTC3869EUF#TRPBF | 28-Lead QFN (4mm x 4mm x 0.75mm w/ EP) | ||
| LTC3869EUFD#PBF | 28-Lead QFN (4mm x 5mm x 0.75mm w/ EP) | ||
| LTC3869EUFD#TRPBF | 28-Lead QFN (4mm x 5mm x 0.75mm w/ EP) | ||
| LTC3869IGN-2#PBF | 28-Lead SSOP (Narrow 0.15 Inch) | ||
| LTC3869IGN-2#TRPBF | 28-Lead SSOP (Narrow 0.15 Inch) | ||
| LTC3869IUF#PBF | 28-Lead QFN (4mm x 4mm x 0.75mm w/ EP) | ||
| LTC3869IUF#TRPBF | 28-Lead QFN (4mm x 4mm x 0.75mm w/ EP) | ||
| LTC3869IUFD#PBF | 28-Lead QFN (4mm x 5mm x 0.75mm w/ EP) | ||
| LTC3869IUFD#TRPBF | 28-Lead QFN (4mm x 5mm x 0.75mm w/ EP) |
| Part Models | Product Lifecycle | PCN |
|---|---|---|
|
Jan 20, 2022 - 21_0269 Addition of Alternate Assembly Site ASE Taiwan for Select LFCSP Products |
||
| LTC3869EUF#PBF | PRODUCTION | |
| LTC3869EUF#TRPBF | PRODUCTION | |
| LTC3869EUFD#PBF | PRODUCTION | |
| LTC3869EUFD#TRPBF | PRODUCTION | |
| LTC3869IUF#PBF | PRODUCTION | |
| LTC3869IUF#TRPBF | PRODUCTION | |
| LTC3869IUFD#PBF | PRODUCTION | |
| LTC3869IUFD#TRPBF | PRODUCTION | |
|
Dec 28, 2020 - 20_0245 Notification of Wafer Fab Location Change for 0.6µm BICMOS Process Devices from ADI Milpitas (Hillview) to Vanguard Int. (Taiwan) |
||
| LTC3869EUF#PBF | PRODUCTION | |
| LTC3869EUF#TRPBF | PRODUCTION | |
| LTC3869EUFD#PBF | PRODUCTION | |
| LTC3869EUFD#TRPBF | PRODUCTION | |
| LTC3869IGN-2#PBF | PRODUCTION | |
| LTC3869IGN-2#TRPBF | PRODUCTION | |
| LTC3869IUF#PBF | PRODUCTION | |
| LTC3869IUF#TRPBF | PRODUCTION | |
| LTC3869IUFD#PBF | PRODUCTION | |
| LTC3869IUFD#TRPBF | PRODUCTION | |
|
Aug 10, 2022 - 22_0177 Laser Top Mark Conversion for QSOP20_24_28 Assembled in ADPG [PNG] and UTL |
||
| LTC3869IGN-2#PBF | PRODUCTION | |
| LTC3869IGN-2#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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|---|---|---|
| Circuit Monitors 1 | ||
| LTC2960 | RECOMMENDED FOR NEW DESIGNS | 36V Nano-Current Two-Input Voltage Monitor |
| Hot Swap Controllers 1 | ||
| LT4363 | RECOMMENDED FOR NEW DESIGNS | High Voltage Surge Stopper with Current Limit |
| Power System Management (PSM) & Sequencers 1 | ||
| LTC2974 | RECOMMENDED FOR NEW DESIGNS | 4-Channel PMBus Power System Manager Featuring Accurate Output Current Measurement |
| Switching Regulators & Controllers 1 | ||
| LTC3880 | RECOMMENDED FOR NEW DESIGNS | Dual Output PolyPhase Step-Down DC/DC Controller with Digital Power System Management |
Tools & Simulations
LTspice 4
- LTC3869-2 Demo Circuit - High Efficiency Dual 3.3V/2.5V Buck Converter using Inductor DCR Current Sensing (4.5-26V to 3.3V & 2.5V @ 5A)
- LTC3869 Demo Circuit - High Efficiency Dual 1.5V/1.2V Buck Converter using Rsense Current Sensing (4.5-14V to 1.5V & 1.2V @ 15A)
- LTC3869-2 Demo Circuit - High Efficiency Dual 3.3V/2.5V Buck Converter using Rsense Current Sensing (4.5-26V to 3.3V & 2.5V @ 5A)
- LTC3869 Demo Circuit - High Efficiency Dual 1.5V/1.2V Buck Converter using Inductor DCR Current Sensing (4.5-14V to 1.5V & 1.2V @ 15A)
Models for the following parts are available in LTspice:
- LTC3869
- LTC3869-2
LTpowerCAD 4
- LTC3869-2 Project - High Efficiency Dual Buck Converter using Rsense Current Sensing (4.5-26V to 3.3V & 2.5V @ 5A)
- LTC3869 Project - High Efficiency Dual 1.5V/1.2V Buck Converter using Inductor DCR Current Sensing (4.5-14V to 1.5V & 1.2V @ 15A)
- LTC3869 Project - Dual, Synchronous Step-Down DC/DC Controllers with Rsense Current Sensing (4.5-14V to 1V @ 15A & 1.5V @ 15A)
- LTC3869-2 Project - Dual, Synchronous Step-Down DC/DC Controllers with Inductor DCR Current Sensing (4.5-26V to 3.3V @ 5A & 2.5V @ 5A)
Design tools for the following parts are available in LTpowerCAD:
- LTC3869
- LTC3869-2
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.
Evaluation Kits
LTC3869IGN-2 Demo Board | VIN = 4.5V to 26V, VOUT1= 3.3V @ 5A, VOUT2 = 2.5V @ 5A, with RSENSE
Resources
LTC3869IGN-2 Demo Board | VIN = 4.5V to 26V, VOUT1 = 3.3V @ 5A, VOUT2 = 2.5V @ 5A, with DCR Sense
Resources
LTC3869EUFD Demo Board | VIN = 4.5V to 14V, VOUT1 = 1.5V @15A, VOUT2 = 1.2V @ 15A, with RSENSE
Resources
LTC3869EUFD Demo Board | VIN = 4.5V to 14V, VOUT1 = 1.5V @15A, VOUT2 = 1.2V @ 15A, with DCR Sense