LTC6908 - Dual Output Oscillator with Spread Spectrum Modulation
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LTC3850 - Dual, 2-Phase Synchronous Step-Down Switching Controller

Features

  • Click Here for LTC3850 Evaluation Kit
  • Dual, 180° Phased Controllers Reduce Required
  • Input Capacitance and Power Supply Induced Noise
  • High Efficiency: Up to 95%
  • RSENSE or DCR Current Sensing
  • ±1% 0.8V Output Voltage Accuracy
  • Phase-Lockable Fixed Frequency 250kHz to 780kHz
  • Supports Pre-Biased Output
  • Dual N-Channel MOSFET Synchronous Drive
  • Wide VIN Range: 4V to 24V (30V for LTC3850I) Operation
  • Adjustable Soft-Start Current Ramping or Tracking
  • Foldback Output Current Limiting
  • Output Overvoltage Protection
  • Power Good Output Voltage Monitor
  • 28-Pin 4mm × 4mm, 4mm × 5mm QFN and Narrow SSOP Packages

Typical Application

LTC3850
LTC3850
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Description

The LTC3850 is a high performance dual synchronous step-down switching regulator controller that drives all N-channel power MOSFET stages. A constant-frequency current mode architecture allows a phase-lockable frequency of up to 780kHz. Power loss and supply noise are minimized by operating the two controller output stages out of phase.

OPTI-LOOP compensation allows the transient response to be optimized over a wide range of output capacitance and ESR values. The LTC3850 features a precision 0.8V reference and a power good output indicator. A wide 4V to 24V (28V maximum/30V for LTC3850I) input supply range encompasses most battery chemistries and intermediate bus voltages.

Independent TK/SS pins for each controller ramp the output voltages during start-up. Current foldback limits MOSFET heat dissipation during short-circuit conditions. The MODE/PLLIN pin selects among Burst Mode operation, pulse-skipping mode, or continuous inductor current mode and allows the IC to be synchronized to an external clock.

The LTC3850 is available in low profile 28-pin 4mm x 4mm, 4mm x 5mm QFN and narrow SSOP packages.
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Packaging

SSOP-28, QFN-28

LTC3850
LTC3850
LTC3850
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Order Info

Package Variations and Pricing

Part Number Package Pins Temp Price (1-99) Price (1k)* RoHS Data
LTC3850EGN#PBF SSOP 28 E $3.43 $2.40 View
LTC3850EGN#TRPBF SSOP 28 E   $2.46 View
LTC3850EGN-1#PBF SSOP 28 E $3.43 $2.40 View
LTC3850EGN-1#TRPBF SSOP 28 E   $2.46 View
LTC3850EUF#PBF QFN 28 E $3.43 $2.40 View
LTC3850EUF#TRPBF QFN 28 E   $2.46 View
LTC3850EUFD#PBF QFN 28 E $3.43 $2.40 View
LTC3850EUFD#TRPBF QFN 28 E   $2.46 View
LTC3850IGN#PBF SSOP 28 I $3.64 $2.55 View
LTC3850IGN#TRPBF SSOP 28 I   $2.61 View
LTC3850IGN-1#PBF SSOP 28 I $3.64 $2.55 View
LTC3850IGN-1#TRPBF SSOP 28 I   $2.61 View
LTC3850IGN-2#PBF SSOP 28 I $3.64 $2.55 View
LTC3850IGN-2#TRPBF SSOP 28 I   $2.61 View
LTC3850IUF#PBF QFN 28 I $3.64 $2.55 View
LTC3850IUF#TRPBF QFN 28 I   $2.61 View
LTC3850IUFD#PBF QFN 28 I $3.64 $2.55 View
LTC3850IUFD#TRPBF QFN 28 I   $2.61 View
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Request Samples
* 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.

Evaluation Kits

Part Number Description Price
DC1126A LTC3850EUF Demo Board | 6.5V ≤ Vin ≤ 14V, Vout 1=3.3V/5A, Vout 2=2.5V/5A $150.00
DC1185A-A LTC3850EUF Demo Board | 6.5V ≤ Vin ≤ 14V, Vout 1=2V/10A, Vout2=1.8V/10A, 500kHz $150.00
DC1185B-B LTC3850EUF Demo Board | 6.5V ≤ Vin ≤ 14V, Vout 1=1.5V/15A, Vout 2=1.2V/15A, 400kHz $150.00
DC1185B-A LTC3850EUF Demo Board | 6.5V ≤ Vin ≤ 14V, Vout 1=2V/10A, Vout 2=1.8V/10A, 500kHz $150.00
DC1231A-A LTC3850EGN Demo Board | 6.5V ≤ Vin ≤ 24V, Vout 1=3.3V/5A, Vout 2=2.5V/5A $150.00
DC1231A-B LTC3850EGN Demo Board | 6.5V ≤ Vin ≤ 24V, Vout 1=3.3V/5A, Vout 2=2.5V/5A, with DCR Current Sense $150.00
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Applications

  • Notebook and Palmtop Computers
  • Portable Instruments
  • Battery-Operated Digital Devices
  • DC Power Distribution Systems
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Simulate

LTSpice / SwitcherCAD III is a powerful FREE circuit simulator and schematic capture program, providing macro models for 80% of Linear Technology's switching regulators, over 200 op amp models, as well as resistors, transistors and MOSFET models.

  • Step 1. If you do not already have a copy of LTSpice, click here to download and install LTSpice / SwitcherCAD III

  • Step 2. Once LTSpice is installed, click here for a ready to run  demonstration circuit of the LT3850.

  • Step 3. If LTspice / SwitcherCAD III does not automatically open after clicking the above link, you can instead run the simulation by right clicking on the link and selecting “Save Target As”. After saving the file to your computer, start LTSpice and open the demonstartion circuit by selecting "Open" from the "File" menu.
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