LTC3890 - 60V Low IQ, Dual, 2-Phase Synchronous Step-Down DC/DC Controller

Features

• Wide V_IN Range: 4V to 60V (65V Abs Max)
• Low Operating I_Q: 50μA (One Channel On)
• Wide Output Voltage Range: 0.8V ≤ V_OUT ≤ 24V
• R_SENSE 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 I_Q : < 14μA
• Internal LDO Powers Gate Drive from V_IN or EXTV_CC
• No Current Foldback During Start-up
• Small Low Profile (0.75mm) 5mm × 5mm QFN Package

Typical Application

Description

The LTC3890 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 LTC3890 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.

Packaging

QFN-32

Order Info

• Part numbers ending in PBF are lead free. Please contact LTC marketing for information on lead based finish parts.
• Part numbers containing TR or TRM are shipped in tape and reel or 500 unit mini tape and reel, respectively
• Please refer to our general ordering information or the product datasheet for more details

Package Variations and Pricing

Part Number	Package	Pins	Temp	Price (1-99)	Price (1k)*	RoHS Data
LTC3890EGN-1#PBF	SSOP	28	E	$6.80	$4.76	View
LTC3890EGN-1#TRPBF	SSOP	28	E		$4.82	View
LTC3890EUH#PBF	QFN	32	E	$6.97	$4.88	View
LTC3890EUH#TRPBF	QFN	32	E		$4.94	View
LTC3890IGN-1#PBF	SSOP	32	I	$7.82	$5.47	View
LTC3890IGN-1#TRPBF	SSOP	32	I		$5.53	View
LTC3890IUH#PBF	QFN	32	I	$7.99	$5.59	View
LTC3890IUH#TRPBF	QFN	32	I		$5.65	View
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^* The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Linear Technology sales office or authorized distributor.

Applications

• Automotive Always-On Systems
• Battery Operated Digital Devices
• Distributed DC Power Systems

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