The LTC3890HGN-1 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 noise due to the ESR of the input capacitor are minimized by operating the two controller output stages out-of-phase.
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 LTC3890HGN-1 features a precision 0.8V reference and power good output indicators. 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 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. For a leaded package version (28-lead Narrow SSOP), see the LTC3890-1 data sheet.
LTC3890HGN-1 LTC3890-1LTC3890-2 LTC3890-3Adjustable Current LimitLimitYes No Yes NoCLKOUT/PHASMD forMultiphase OperationYes No YesNoNumber of PGoodOutputs2 1 2 1OVP – Bottom GateCrowbarYesYesNoNoCurrent Limit FoldbackYesYes No NoLight Load Operationwhen Synced to ExternalClockForced ContinuousForced ContinuousPulse SkippingPulse SkippingSENSE Pins CommonMode RangeCommon Mode < 0.5VRequires VFB < 0.65VCommon Mode < 0.5VRequires VFB < 0.65VNot Dependant onVFB. Easy to make anon-synchronousBoost or SEPICNot Dependant onVFB. Easy to make anon-synchronousBoost or SEPICPackage 5 × 5 QFN-32SSOP-28 5 × 5 QFN-32 SSOP-28Feature
- 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 Required 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
- Selectable Current Limit
- Very Low Dropout Operation: 99% Duty Cycle
- Adjustable Output Voltage Soft-Start or Tracking
- Power Good Output Voltage Monitors
- Output Overvoltage Protection
- Low Shutdown IQ : < 14μA
- Internal LDO Powers Gate Drive from VIN or EXTVCC
- No Current Foldback During Start-Up
- Small Low Profile (0.75mm) 5mm × 5mm QFN Package
Applications
- Automotive Always-On Systems
- Battery Operated Digital Devices
- Distributed DC Power Systems
(Picture: Pinout)
