LTC3868-1 - Low IQ, Dual 2-Phase Synchronous Step-Down Controller
The LTC3868-1 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 LTC3868-1 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 leadless 32-pin QFN package with the additional features of adjustable current limit, clock out, phase modulation and two PGOOD outputs, see the LTC3868 data sheet.
Features- 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 4mm × 5mm QFN and Narrow SSOP Packages
Typical Application
| Applications- Notebook and Palmtop Computers
- Portable Instruments
- Battery Operated Digital Devices
- Distributed DC Power Systems
Packaging
|
Order Information
Part Number | Package | Temp | Price(1-99) | Price (1k)* |
---|
LTC3868EGN-1#PBF | SSOP-28 | E | $3.70 | $2.59 |
LTC3868EGN-1#TRPBF | SSOP-28 | E | | $2.65 |
LTC3868EUFD-1#PBF | 4x5 QFN-28 | E | $3.87 | $2.71 |
LTC3868EUFD-1#TRPBF | 4x5 QFN-28 | E | | $2.77 |
LTC3868IGN-1#PBF | SSOP-28 | I | $4.03 | $2.82 |
LTC3868IGN-1#TRPBF | SSOP-28 | I | | $2.88 |
LTC3868IUFD-1#PBF | 4x5 QFN-28 | I | $4.20 | $2.94 |
LTC3868IUFD-1#TRPBF | 4x5 QFN-28 | I | | $3.00 |
DatasheetReliability DataPress Release | Related Product- LT8705 - 80V VIN and VOUT Synchronous 4-Switch Buck- Boost DC/DC Controller
- LTC4364 - Surge Stopper with Ideal Diode
- LTC3868 - Low IQ, Dual 2-Phase Synchronous Step-Down Controller
- LT3763 - 60V High Current Step-Down LED Driver Controller
- LTC3810 - 100V Current Mode Synchronous Switching Regulator Controller
- LTC3639 - High Efficiency, 150V 100mA Synchronous Step-Down Regulator
- LTC3890 - 60V Low IQ, Dual, 2-Phase Synchronous Step-Down DC/DC Controller
- LTC3891 - Low IQ, 60V Synchronous Step-Down Controller
- LT3757 - Boost, Flyback, SEPIC and Inverting Controller
- LT3758 - High Input Voltage, Boost, Flyback, SEPIC and Inverting Controller
|