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LTC3890-3
60V Low IQ, Dual, 2-Phase Synchronous Step-Down DC/DC Controller
Overview
Features and Benefits
- Wide VIN Range: 4V to 60V (65V Abs Max)
- Low Operating IQ: 50μA (One Channel On)
- Wide Output Voltage Range: 0.8V ≤ VOUT ≤ 24V
- RSENSE or DCR Current Sensing
- Out-of-Phase Controllers Reduce Input Capacitance and Power Supply Induced Noise
- Phase-Lockable Frequency (75kHz to 850kHz)
- Programmable Fixed Frequency (50kHz to 900kHz)
- Selectable Continuous, Pulse-Skipping or Low Ripple Burst Mode® Operation at Light Loads
- Very Low Dropout Operation: 99% Duty Cycle
- Adjustable Output Voltage Soft-Start or Tracking
- Power Good Output Voltage Monitor
- Low Shutdown IQ: <14μA
- Internal LDO Powers Gate Drive from VIN or EXTVCC
- Narrow SSOP Package
Product Details
The LTC3890-3 is a high performance dual step-down switching regulator DC/DC 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 supply noise are minimized by operating the two controller output stages out-of-phase.
The 50μA 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. A wide 4V to 60V input supply range encompasses a wide range of intermediate bus voltages and battery chemistries.
Independent TRACK/SS pins for each controller ramp the output voltages during start-up. Current mode control limits the inductor current during short-circuit conditions. The PLLIN/MODE pin selects among Burst Mode operation, pulse-skipping mode, or continuous conduction mode at light loads.
For versions with different and/or additional features, see the LTC3890 family summary, Table 1, in the Pin Functions section of this data sheet.
| LTC3890 | LTC3890-1 | LTC3890-2 | LTC3890-3 | |
| Adjustable Current Limit | Yes | No | Yes | No |
| CLKOUT/PHASMD for Multiphase Operation |
Yes | No | Yes | No |
| Number of PGood Outputs |
2 | 1 | 2 | 1 |
| OVP – Bottom Gate Crowbar |
Yes | Yes | No | No |
| Current Limit Foldback | Yes | Yes | No | No |
| Light Load Operation when Synced to External Clock |
Forced Continuous | Forced Continuous | Pulse Skipping | Pulse Skipping |
| SENSE Pins Common Mode Range |
Common Mode < 0.5V Requires VFB < 0.65V |
Common Mode < 0.5V Requires VFB < 0.65V |
Not Dependant on VFB. Easy to make a non-synchronous Boost or SEPIC |
Not Dependant on VFB. Easy to make a non-synchronous Boost or SEPIC |
| Package | 5X5 QFN-32 | SSOP-28 | 5X5 QFN-32 | SSOP-28 |
Applications
- Automotive Always-On Systems
- Battery Operated Digital Devices
- Distributed DC Power Systems
Product Lifecycle
Recommended for New Designs
This product has been released to the market. The data sheet contains all final specifications and operating conditions. For new designs, ADI recommends utilization of these products.
Evaluation Kits (1)
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Tools & Simulations
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Reference Materials
Technical Articles (1)
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