LTC3311/
LTC3311-X
Info : RECOMMENDED FOR NEW DESIGNS
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LTC3311/
LTC3311-X

5V, 12.5A Synchronous Step-Down Silent Switcher in 3mm × 3mm LQFN

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Info : RECOMMENDED FOR NEW DESIGNS tooltip
Info : RECOMMENDED FOR NEW DESIGNS tooltip
Part Details
Part Models 36
1ku List Price Starting From $4.42
Features
  • Pin Compatible with LTC3310/LTC3310S and LTC3311S
  • Silent Switcher® Architecture:
    • Ultralow EMI Emissions
  • High Efficiency—4.5mΩ NMOS and 16mΩ PMOS
  • Wide Bandwidth, Fast Transient Response
  • Safely Tolerates Inductor Saturation in Overload
  • VIN Range: 2.25V to 5.5V
  • VOUT Range: 0.5V to VIN
  • VOUT Accuracy: ±1% with Remote Sense
  • Peak Current Mode Control
  • Minimum On-Time: 35ns
  • Programmable Frequency to 5MHz
  • Precision 400mV Enable Threshold, 1µA in Shutdown
  • Output Soft-Start with Voltage Tracking
  • Power Good Output
  • Die Temperature Monitor
  • Configurable for Paralleling Power Stages in Forced Continuous Mode
  • Thermally-Enhanced 3mm × 3mm LQFN Package
  • AEC-Q100 Qualified for Automotive Applications
Additional Details
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The LTC3311/LTC3311-X is a very small, low noise, monolithic step-down DC/DC converter capable of providing up to 12.5A of output current from a 2.25V to 5.5V input supply. The device employs Silent Switcher 1 architecture to achieve both low EMI and high efficiency at switching frequencies as high as 5MHz. For systems with higher power requirements, multi-phasing parallel converters is readily implemented.

The LTC3311/LTC3311-X uses a constant frequency, peak current mode control architecture for fast transient response. A 500mV reference allows for low voltage outputs. 100% duty cycle operation delivers low drop out.

Other features include a power good signal when the output is in regulation, precision enable threshold, output overvoltage protection, thermal shutdown, a temperature monitor, clock synchronization, mode selection and output short circuit protection. The device is available in a compact 18-lead 3mm × 3mm LQFN package.

APPLICATIONS

  • Automotive/Industrial/Communications
  • Servers, Telecom Power Supplies
  • Distributed DC Power Systems (POL)
  • FPGA, ASIC, μP Core Supplies
Part Models 36
1ku List Price Starting From $4.42

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Documentation

Documentation

Part Model Pin/Package Drawing Documentation CAD Symbols, Footprints, and 3D Models
LTC3311HV#PBF
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LTC3311JV-0.75#PBF
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Software & Part Ecosystem

Software & Part Ecosystem

Evaluation Kit

Evaluation Kits 6

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DC3056A

LTC3311 | 3.3V to 1.2V at 12.5A, 2MHz Automotive Low EMI Buck Regulator in a 1.22cm2 Solution

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DC3056A

LTC3311 | 3.3V to 1.2V at 12.5A, 2MHz Automotive Low EMI Buck Regulator in a 1.22cm2 Solution

LTC3311 | 3.3V to 1.2V at 12.5A, 2MHz Automotive Low EMI Buck Regulator in a 1.22cm2 Solution

Product Detail

Demonstration circuit 3056A features the LTC3311, 12.5A, low voltage synchronous step-down Silent Switcher® operating as a 2MHz, 2.25V–5.5V input, 1.2V 12.5A output buck regulator. The LTC3311 supports output voltages from 0.5V to VIN with operating frequencies from 500kHz up to 5MHz. The LTC3311 is a compact, ultralow emission, high efficiency, and high speed synchronous monolithic step-down switching regulator. The Silent Switcher technology optimizes fast-current loops and makes it easier to minimize EMI/EMC emissions. Fast minimum on-time of 35ns enables high VIN to low VOUT conversion at high frequency.

DC3056A is set up to run in forced continuous mode with a 2MHz switching frequency but can be configured to pulse-skipping mode and different switching frequencies. RT is connected to VIN which sets the MODE/SYNC pin as an input and allows the LTC3311 to sync from an external clock. Connecting the MODE/SYNC pin to VIN sets the mode to forced continuous mode and connecting the MODE/SYNC pin to GND sets the mode to pulse-skipping.

Figure 5 in the demo manual shows the efficiency and power loss of the circuit with a 3.3V input in forced continuous mode operation. The DC3056A also has an EMI filter to reduce conducted EMI. This EMI filter can be included by applying the input voltage at the VIN EMI terminal. The EMI performance of the board is shown in the EMI Test Results section. The red lines in Figure 7 through Figure 9 in the demo manual illustrate the CISPR25 Class 5 peak limits for the conducted and radiated emission tests.

The LTC3311 data sheet gives a complete description of the device, operation and application information. The data sheet must be read in conjunction with the demo manual. The LTC3311 is assembled in a 3mm × 3mm LQFN-18 package with exposed pads for low thermal resistance. The layout recommendations for low EMI operation and maximum thermal performance are available in the data sheet section Low EMI PCB Layout.

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DC3186A

LTC3311 | 3.3V to 1.2V at 50A, 37.5A, 25A Multiphase 2MHz Automotive Low EMI Buck Regulator

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DC3186A

LTC3311 | 3.3V to 1.2V at 50A, 37.5A, 25A Multiphase 2MHz Automotive Low EMI Buck Regulator

LTC3311 | 3.3V to 1.2V at 50A, 37.5A, 25A Multiphase 2MHz Automotive Low EMI Buck Regulator

Product Detail

Demonstration Circuit 3186A features the LTC3311 12.5A, low voltage synchronous step-down Silent Switcher® operating as a multiphase 2MHz, 3V to 5.5V input, 1.2V buck regulator. The DC3186A has three build options to provide a two phase 25A, three phase 37.5A, or four phase 50A output solution. The LTC3311 supports adjustable output voltages from 0.5V to VIN and operating frequencies from 500kHz up to 5MHz in multiphase operation. All phases of DC3186A operate in forced continuous mode.

The DC3186A also has an EMI filter to reduce conducted EMI. This EMI filter can be included by applying the input voltage at the VIN EMI terminal.

The Efficiency vs Load graph shows the efficiency of the circuit with a 3.3V input for all three build options.

An on-board transient circuit is included to measure fast transient performance.

The LTC3311 data sheet gives a complete description of the part, its operation, and application information. The data sheet must be read in conjunction with the demo manual. The LTC3311 is assembled in a 3mm × 3mm LQFN package with exposed pads for low thermal resistance.

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DC3059A

LTC3311-0.85 | 3.3V to 0.85V at 12.5A, 2MHz Automotive Low EMI Buck Regulator in a 1.04cm2 Solution

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DC3059A

LTC3311-0.85 | 3.3V to 0.85V at 12.5A, 2MHz Automotive Low EMI Buck Regulator in a 1.04cm2 Solution

LTC3311-0.85 | 3.3V to 0.85V at 12.5A, 2MHz Automotive Low EMI Buck Regulator in a 1.04cm2 Solution

Product Detail

Demonstration Circuit 3059A features the LTC3311-0.85, fixed 0.85V, 12.5A synchronous step-down Silent Switcher® operating as a 2MHz, 3V to 3.6V input, 0.85V/12.5A output buck regulator. The LTC3311-0.85 supports fixed 0.85V output voltage with operating frequencies from 500kHz up to 5MHz. The LTC3311-0.85 is a compact, ultralow emission, high efficiency, and high speed synchronous monolithic step-down switching regulator. The LTC3311-0.85 has Active Voltage Positioning (AVP) where the output voltage is dependent on load current. At light loads the output voltage is regulated above the nominal value. At full load the output voltage is regulated below the nominal value. The DC load regulation is adjusted to improve transient performance and reduce required output capacitance.

DC3059A is set up to run in forced continuous mode with a 2MHz switching frequency but can be configured to run at different switching frequencies, or in pulse skip mode. The LTC3311-0.85 oscillator can also synchronize to an external clock using MODE/SYNC turret, with the DC3059 default setup. Figure 5 shows the efficiency and power loss of the DC3059A with a 3.3V input in both operation modes.

The DC3059A is optimized for keeping its output within ±3% of the target voltage during a 4A to 8A, 4A/μs load step transient. A fast load step transient circuit is placed on the back of the demo board to measure the load step response of the converter.

The DC3059A also has an EMI filter to reduce conducted EMI. This EMI filter can be included by applying the input voltage at the VIN EMI terminal. The EMI performance of the board is shown in the EMI Test Results section. The red lines in the EMI performance graphs illustrate the CISPR25 Class 5 peak limits for the conducted and radiated emission tests.

The LTC3311-0.85 data sheet gives a complete description of the part and its application information. The data sheet must be read in conjunction with the demo manual. The LTC3311-0.85 is assembled in a 3mm × 3mm LQFN package with exposed pads for low thermal resistance. The layout recommendations for low EMI operation and maximum thermal performance are available in the data sheet section Low EMI PCB Layout.

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DC3217A

LTC3311-0.75 | 3.3V to 0.75V at 12.5A, 2MHz Automotive Low EMI Buck Regulator

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DC3217A

LTC3311-0.75 | 3.3V to 0.75V at 12.5A, 2MHz Automotive Low EMI Buck Regulator

LTC3311-0.75 | 3.3V to 0.75V at 12.5A, 2MHz Automotive Low EMI Buck Regulator

Product Detail

Demonstration Circuit 3217A features the LTC3311-0.75, fixed 0.75V, 12.5A synchronous step-down Silent Switcher® operating as a 2MHz, 3V to 3.6V input, 0.75V at 12.5A output buck regulator. The LTC3311-0.75 supports fixed 0.75V output voltage with operating frequencies from 500kHz up to 5MHz. The LTC3311-0.75 is a compact, ultralow emission, high efficiency, and high speed synchronous monolithic step-down switching regulator. The LTC3311-0.75 has Active Voltage Positioning (AVP) where the output voltage is dependent on load current. At light load, the output voltage is regulated above the nominal value. At full load, the output voltage is regulated below the nominal value. The DC load regulation is adjusted to improve transient performance and reduce required output capacitance.

DC3217A is set up to run in forced continuous mode with a 2MHz switching frequency but can be configured to run at different switching frequencies, or in pulse-skipping mode. The LTC3311-0.75 oscillator can also synchronize to an external clock using MODE/SYNC turret, with the DC3217A default setup. Figure 7 in the demo manual shows the efficiency and power loss of the DC3217A with a 3.3V input in both operation modes.

The DC3217A is optimized for keeping its output within ±3% of the target voltage during a 4A to 12A, 8A/μs load step transient. A fast load step transient circuit is placed on the back of the demo board to measure the load step response of the converter.

The DC3217A also has an EMI filter to reduce conducted EMI. This EMI filter can be included by applying the input voltage at the VIN EMI terminal. The EMI performance of the board is shown in the EMI Test Results section. The red lines in the EMI performance graphs illustrate the CISPR25 Class 5 peak limits for the conducted and radiated emission tests.

The LTC3311-0.75 data sheet gives a complete description of the part and its application information. The data sheet must be read in conjunction with the demo manual. The LTC3311-0.75 is assembled in a 3mm × 3mm LQFN package with exposed pads for low thermal resistance. The layout recommendations for low EMI operation and maximum thermal performance are available in the data sheet section Low EMI PCB Layout.

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DC3113A

LTC3311-1 | 3.3V to 1V at 12.5A, 2MHz Automotive Low EMI Buck Regulator

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DC3113A

LTC3311-1 | 3.3V to 1V at 12.5A, 2MHz Automotive Low EMI Buck Regulator

LTC3311-1 | 3.3V to 1V at 12.5A, 2MHz Automotive Low EMI Buck Regulator

Product Detail

Demonstration Circuit 3113A features the LTC3311-1, fixed 1V, 12.5A synchronous step-down Silent Switcher® operating as a 2MHz, 3V to 3.6V input, 1V/12.5A output buck regulator. The LTC3311-1 supports fixed 1V output voltage with operating frequencies from 500kHz up to 5MHz. The LTC3311-1 is a compact, ultralow emission, high efficiency, and high speed synchronous monolithic step-down switching regulator. The LTC3311-1 has Active Voltage Positioning (AVP) where the output voltage is dependent on load current. At light load, the output voltage is regulated above the nominal value. At full load, the output voltage is regulated below the nominal value. The DC load regulation is adjusted to improve transient performance and reduce required output capacitance.

DC3113A is set up to run in forced continuous mode with a 2MHz switching frequency but can be configured to run at different switching frequencies, or in pulse-skipping mode. The LTC3311-1 oscillator can also synchronize to an external clock using MODE/SYNC turret, with the DC3113A default setup. Figure 7 in the demo manual shows the efficiency and power loss of the DC3113A with a 3.3V input in both operation modes.

The DC3113A is optimized for a 4A to 12A, 8A/μs load step transient. A fast load step transient circuit is placed on the back of the demo board to measure the load step response of the converter.

The DC3113A also has an EMI filter to reduce conducted EMI. This EMI filter can be included by applying the input voltage at the VIN EMI terminal. The EMI performance of the board is shown in the EMI TEST RESULTS section. The red lines in the EMI performance graphs illustrate the CISPR25 Class 5 peak limits for the conducted and radiated emission tests.

The LTC3311-1 data sheet gives a complete description of the part and its application information. The data sheet must be read in conjunction with this demo manual. The LTC3311-1 is assembled in a 3mm × 3mm LQFN package with exposed pads for low thermal resistance. The layout recommendations for low EMI operation and maximum thermal performance are available in the data sheet section Low EMI PCB Layout.

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DC3127A

LTC3311-0.875 | 3.3V to 0.875V at 12.5A, 2MHz Automotive Low EMI Buck Regulator in a 1.04cm2 Solution

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DC3127A

LTC3311-0.875 | 3.3V to 0.875V at 12.5A, 2MHz Automotive Low EMI Buck Regulator in a 1.04cm2 Solution

LTC3311-0.875 | 3.3V to 0.875V at 12.5A, 2MHz Automotive Low EMI Buck Regulator in a 1.04cm2 Solution

Product Detail

Demonstration circuit 3127A features the LTC3311-0.875, fixed 0.875V, 12.5A synchronous step-down Silent Switcher® operating as a 2MHz, 3V to 3.6V input, 0.875V/12.5A output buck regulator. The LTC3311-0.875 supports fixed 0.875V output voltage with operating frequencies from 500kHz up to 5MHz. The LTC3311-0.875 is a compact, ultralow emission, high efficiency, and high speed synchronous monolithic step-down switching regulator. The LTC3311-0.875 has Active Voltage Positioning (AVP) where the output voltage is dependent on load current. At light loads the output voltage is regulated above the nominal value. At full load the output voltage is regulated below the nominal value. The DC load regulation is adjusted to improve transient performance and reduce required output capacitance.

DC3127A is set up to run in forced continuous mode with a 2MHz switching frequency but can be configured to run at different switching frequencies, or in pulse skip mode. The LTC3311-0.875 oscillator can also synchronize to an external clock using MODE/SYNC turret, with the DC3127 default setup. Figure 5 in the demo manual shows the efficiency and power loss of the DC3127A with a 3.3V input in both operation modes.

The DC3127A is optimized for keeping its output within ±3% of the target voltage during a 4A to 8A, 4A/μs load step transient. A fast load step transient circuit is placed on the back of the demo board to measure the load step response of the converter.

The DC3127A also has an EMI filter to reduce conducted EMI. This EMI filter can be included by applying the input voltage at the VIN EMI terminal. The EMI performance of the board is shown in the EMI TEST RESULTS section. The red lines in the EMI performance graphs illustrate the CISPR25 Class 5 peak limits for the conducted and radiated emission tests.

The LTC3311-0.875 data sheet gives a complete description of the part and its application information. The data sheet must be read in conjunction with the demo manual. The LTC3311-0.875 is assembled in a 3mm × 3mm LQFN package with exposed pads for low thermal resistance. The layout recommendations for low EMI operation and maximum thermal performance are available in the data sheet section Low EMI PCB Layout.

Tools & Simulations

Tools & Simulations 1

LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.

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