LTC3868
PRODUCTIONLow IQ, Dual 2-Phase Synchronous Step-Down Controller
- Part Models
- 4
- 1ku List Price
- Starting From $4.13
Overview
- Low Operating IQ: 170μA (One Channel On)
- Wide Output Voltage Range: 0.8V ≤ VOUT ≤ 14V
- Wide VIN Range: 4V to 24V
- RSENSE or DCR Current Sensing
- Out-of-Phase Controllers Reduce Required Input Capacitance and Power Supply Induced Noise
- OPTI-LOOP® Compensation Minimizes COUT
- Phase-Lockable Frequency (75kHz to 850kHz)
- Programmable Fixed Frequency (50kHz to 900kHz)
- Selectable Continuous, Pulse-Skipping or Burst Mode® Operation at Light Loads
- Very Low Dropout Operation: 99% Duty Cycle
- Adjustable Output Voltage Soft-Start
- Power Good Output Voltage Monitor
- Output Overvoltage Protection
- Output Latchoff Protection During Short Circuit
- Low Shutdown IQ: 8μA
- Internal LDO Powers Gate Drive from VIN or EXTVCC
- No Current Foldback During Start-Up
- Small 5mm × 5mm QFN Package
The LTC3868 is a high performance dual 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 850kHz. Power loss and noise due to the input capacitor ESR are minimized by operating the two controller outputs out of phase.
The 170μA no-load quiescent current extends operating life 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 LTC3868 features a precision 0.8V reference and a power good output indicator. A wide 4V to 24V input supply range encompasses a wide range of intermediate bus voltages and battery chemistries.
Independent soft-start pins for each controller ramp the output voltages during start-up. Current foldback limits MOSFET heat dissipation during short-circuit conditions. The output short-circuit latchoff feature further protects the circuit in short-circuit conditions.
For a leaded 28-lead SSOP package with a fixed current limit and one PGOOD output, without phase modulation or a clock output, see the LTC3868-1 data sheet.
| LTC3868 | LTC3868-1 | |
| Features | Adjustable Current Limit, Clock Out Pin, Phase Modulation, Two PGOOD | Fixed Current Limit, One PGOOD |
| Package | QFN-32 | SSOP-28 |
Applications
- Notebook and Palmtop Computers
- Portable Instruments
- Battery Operated Digital Devices
- Distributed DC Power Systems
Documentation
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 |
|---|---|---|---|
| LTC3868EUH#PBF | 32-Lead QFN (5mm x 5mm x 0.75mm w/ EP) | ||
| LTC3868EUH#TRPBF | 32-Lead QFN (5mm x 5mm x 0.75mm w/ EP) | ||
| LTC3868IUH#PBF | 32-Lead QFN (5mm x 5mm x 0.75mm w/ EP) | ||
| LTC3868IUH#TRPBF | 32-Lead QFN (5mm x 5mm x 0.75mm w/ EP) |
| Part Models | Product Lifecycle | PCN |
|---|---|---|
|
Feb 14, 2025 - 25_0017 Bond Wire Change from Gold to Copper |
||
| LTC3868EUH#PBF | PRODUCTION | |
| LTC3868EUH#TRPBF | PRODUCTION | |
| LTC3868IUH#PBF | PRODUCTION | |
| LTC3868IUH#TRPBF | PRODUCTION | |
|
Jan 20, 2022 - 21_0269 Addition of Alternate Assembly Site ASE Taiwan for Select LFCSP Products |
||
| LTC3868EUH#PBF | PRODUCTION | |
| LTC3868EUH#TRPBF | PRODUCTION | |
| LTC3868IUH#PBF | PRODUCTION | |
| LTC3868IUH#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) |
||
| LTC3868EUH#PBF | PRODUCTION | |
| LTC3868EUH#TRPBF | PRODUCTION | |
| LTC3868IUH#PBF | PRODUCTION | |
| LTC3868IUH#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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| Overvoltage & Overcurrent Protectors 1 | ||
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| Power System Management (PSM) & Sequencers 1 | ||
| LTC2974 | RECOMMENDED FOR NEW DESIGNS | 4-Channel PMBus Power System Manager Featuring Accurate Output Current Measurement |
Tools & Simulations
LTspice
Models for the following parts are available in LTspice:
- LTC3868
- LTC3868-1
LTpowerCAD 1
Design tools for the following parts are available in LTpowerCAD:
- LTC3868
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.
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