LTC3887/LTC3887-1 - Dual Output PolyPhase Step-Down DC/DC Controller with Digital Power System Management

Features

  • Order Custom Programmed Parts
  • PMBus/I2C Compliant Serial Interface
  • Telemetry Read Back includes VIN, IIN, VOUT, IOUT,
  • Temperature, Duty Cycle and Faults
  • Programmable Voltage, Current Limit, Digital Soft-Start/Stop, Sequencing, Margining, OV/UV and Frequency Synchronization (250kHz to 1MHz)
  • ±0.5% Output Voltage Accuracy Over Temperature
  • Integrated 16-Bit ADC
  • VOUT Range: 0.5V to 5.5V (VOUT0, VOUT1)
  • Internal EEPROM and Fault Logging with ECC
  • Integrated N-Channel MOSFET Gate Drivers (LTC3887)
  • Minimum On-Time 45ns
  • Wide VIN Range: 4.5V to 24V
  • Analog Current Mode Control Loop
  • Remote Differential Sense for PolyPhase® Applications
  • Accurate PolyPhase Current Sharing for Up to Six Phases
  • Available in a 40-Pin (6mm × 6mm) QFN Package
  • Download LTpowerPlay software
Designed for Automotive and Transportation Applications
AEC-Q100 data available for specific packages


Typical Application

LTC3887 Typical Application
LTC3887 Typical Application

Description

The LTC®3887/LTC3887-1 are dual, PolyPhase DC/DC synchronous step-down switching regulator controllers with an I2C-based PMBus compliant serial interface. The controllers use a constant frequency, current mode architecture that is supported by LTpowerPlay® a software development tool with graphical user interface (GUI).

Switching frequency, channel phasing, output voltage, and device address can be programmed using external configuration resistors. Additionally, parameters can be set via the digital interface or stored in EEPROM. Voltage, current, internal/external temperature and fault status can be read back through the bus interface.

The LTC3887 has integrated gate drivers. The LTC3887-1 has three-state PWM pins to drive power blocks or DrMOS power stages. The LTC3887 is an enhanced version of the LTC3880 with greater output voltage range and more digital features. Refer to page 15 for more detail.

Packaging

CAD Symbols and Footprints: The downloadable Zip file below contains the schematic symbol and PCB footprints.

For complete and up to date package information and drawings, please refer to our packaging page

Part Number Package Code Temp Package
Drawing
RoHS
LTC3887EUJ-1#PBF 6x6 QFN-40 UJ E 05-08-1728 Yes
LTC3887EUJ-1#TRPBF 6x6 QFN-40 UJ E 05-08-1728 Yes
LTC3887EUJ#PBF 6x6 QFN-40 UJ E 05-08-1728 Yes
LTC3887EUJ#TRPBF 6x6 QFN-40 UJ E 05-08-1728 Yes
LTC3887IUJ-1#PBF 6x6 QFN-40 UJ I 05-08-1728 Yes
LTC3887IUJ-1#TRPBF 6x6 QFN-40 UJ I 05-08-1728 Yes
LTC3887IUJ#PBF 6x6 QFN-40 UJ I 05-08-1728 Yes
LTC3887IUJ#TRPBF 6x6 QFN-40 UJ I 05-08-1728 Yes


LTC3887 Package Drawing

Order Info

  • Part numbers ending in PBF are lead free. Solder plated terminal finish (SnPb) versions are non-standard and special terms and conditions and pricing applies if available. Please contact LTC marketing for information.
  • 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 Temp Price
(1-99)
Price
(1k)*
RoHS
LTC3887EUJ-1#PBF 6x6 QFN-40 E $7.82 $5.47 Yes
LTC3887EUJ-1#TRPBF 6x6 QFN-40 E $5.53 Yes
LTC3887EUJ#PBF 6x6 QFN-40 E $7.82 $5.47 Yes
LTC3887EUJ#TRPBF 6x6 QFN-40 E $5.53 Yes
LTC3887IUJ-1#PBF 6x6 QFN-40 I $8.99 $6.29 Yes
LTC3887IUJ-1#TRPBF 6x6 QFN-40 I $6.35 Yes
LTC3887IUJ#PBF 6x6 QFN-40 I $8.99 $6.29 Yes
LTC3887IUJ#TRPBF 6x6 QFN-40 I $6.35 Yes
Buy NowRequest 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.

Demo Boards

Linear Technology offers many demo boards free of charge to qualified customers. Contact your local sales office or distributor to inquire about a demo board. Certain demo boards are also available for sale via credit card on this website. Demo boards are for evaluation purposes only. It remains the customer’s responsibility to verify proper and reliable operation in the actual end application.

Part Number Description Price Documentation
DC1709A LTC3880/-1 & LTC3887/-1 Demo Board I Programming Clamshell Socketed Demo Board $125.00
DC2263A-A LTC3887EUJ Demo Board (RSENSE) | Dual PMBus Buck, 7V ≤ VIN ≤ 18V, Vout0/Vout1 = 0.8V to 1.8V @ 25A Contact Factory
DC2263A-B LTC3887EUJ Demo Board (DCR SENSE) | 2 Phase PMBus Buck, 7V ≤ VIN ≤ 18V, Vout = 0.8V to 1.8V @ 50A Contact Factory
DC2394A LTC3887EUJ-1 Demo Board (DCR Sense) | PMBus Buck with DrMOS, 7V ≤ VIN ≤ 14V, Vout0/Vout1 = 0.8V to 1.8V @ 30A Contact Factory
DC2454A LTC3887EUJ-1/LTC3870EUF-1 Demo Board | Dual Phase PMBus Buck Controller with Slave Controller, 7V ≤ VIN ≤ 14V, 0.8V ≤ VOUT ≤ 1.8V @ 100A Contact Factory
Buy Now

Companion Boards

Part Number Description Price Documentation
DC1613A USB-to-PMBus Controller for Use with LTpowerPlay $50.00
DC2026C Linduino One Isolated USB Demo Board: An Arduino- and QuikEval-Compatible Code Development Platform $75.00
DC2086A Powered Programming Adapter for Digital Power System Management Products $199.00
Buy Now
Click here to view our complete list of demo boards

Designed for Automotive and Transportation Applications

AEC-Q100 data is available for these specific part numbers. Please contact your local sales representative for more information regarding reliability reports or to inquire about parts that are not included. For more information, view our Automotive and Transportation page

Part Number Package Temp Price
(1-99)
Price
(1k)*
RoHS
LTC3887EUJ-1#PBF 6x6 QFN-40 E $7.82 $5.47 Yes
LTC3887EUJ-1#TRPBF 6x6 QFN-40 E $5.53 Yes
LTC3887EUJ#PBF 6x6 QFN-40 E $7.82 $5.47 Yes
LTC3887EUJ#TRPBF 6x6 QFN-40 E $5.53 Yes
LTC3887IUJ-1#PBF 6x6 QFN-40 I $8.99 $6.29 Yes
LTC3887IUJ-1#TRPBF 6x6 QFN-40 I $6.35 Yes
LTC3887IUJ#PBF 6x6 QFN-40 I $8.99 $6.29 Yes
LTC3887IUJ#TRPBF 6x6 QFN-40 I $6.35 Yes
Buy NowRequest 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.

Applications

  • High Current Distributed Power Systems
  • Telecom, Datacom and Storage Systems
  • Intelligent Energy Efficient Power Regulation

Product Notifications

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Need help? Email mylinear@linear.com with questions and comments.

Design Tools

LTpowerPlay

LTpowerPlay is a powerful development environment supporting Linear Technology's Digital Power System Management (PSM) products, providing unprecedented diagnostic and debug features.

Click here to download LTpowerPlay

LTspice

LTspice® software is a powerful, fast and free simulation tool, schematic capture and waveform viewer with enhancements and models for improving the simulation of switching regulators. Click here to download LTspice

Models for the following parts are available in LTspice:
LTC3887

LTpowerCAD

The LTpowerCAD design tool is a complete power supply design tool program that can significantly ease the tasks of power supply design. It guides users to a solution, selects power stage components, provides detailed power efficiency, shows quick loop bode plot stability and load transient analysis, and can export a final design to LTspice for simulation. Click here to download LTpowerCAD

To open the project file for this circuit:

Design tools for the following parts are available in LTpowerCAD:
LTC3887
LTC3887 Parallel

Linduino

Linduino is an Arduino compatible platform for developing and distributing firmware libraries and code for SPI and I²C-compatible integrated circuits. The Linduino One board interfaces to more than 300 QuikEval demonstration cards, supporting a variety of product types including analog-to-digital converters (ADCs)digital-to-analog converters (DACs)power monitors, and more. Firmware libraries for individual devices are written in C and designed to be portable to a wide variety of processors and microcontrollers. Each library has a demonstration program that can be uploaded to the Linduino One platform to allow the circuit and software to be quickly and easily verified.

Click here for more information on Linduino

Code

Linduino is Linear Technology's Arduino compatible system for developing and distributing firmware libraries and example code for Linear Technology’s integrated circuits. The code below can be downloaded or copied and pasted into your project. Please visit the Linduino Home Page for demo board, manual and setup information.

This part is Code Supported: There is example code available for this part. The code below may rely on other drivers available in the full library.

Download LTC3887 - DC2263A.ino

/*!
Linear Technology DC2263A Demonstration Board
LTC3887: Dual Output PolyPhase Step-Down DC/DC Controller with Digital Power System Management

@verbatim

NOTES
  Setup:
   Set the terminal baud rate to 115200 and select the newline terminator.

@endverbatim

http://www.linear.com/product/LTC3887

http://www.linear.com/demo/DC2263A

REVISION HISTORY
$Revision: 4376 $
$Date: 2015-11-20 14:31:33 -0700 (Fri, 20 Nov 2015) $

Copyright (c) 2014, Linear Technology Corp.(LTC)
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

1. Redistributions of source code must retain the above copyright notice, this
   list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright notice,
   this list of conditions and the following disclaimer in the documentation
   and/or other materials provided with the distribution.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

The views and conclusions contained in the software and documentation are those
of the authors and should not be interpreted as representing official policies,
either expressed or implied, of Linear Technology Corp.

The Linear Technology Linduino is not affiliated with the official Arduino team.
However, the Linduino is only possible because of the Arduino team's commitment
to the open-source community.  Please, visit http://www.arduino.cc and
http://store.arduino.cc , and consider a purchase that will help fund their
ongoing work.
*/

/*! @file
    @ingroup LTC3880
*/

#include <Arduino.h>
#include <stdint.h>
#include "Linduino.h"
#include "UserInterface.h"
#include "LT_I2CBus.h"
#include "LT_SMBusNoPec.h"
#include "LT_SMBusPec.h"
#include "LT_PMBus.h"

#define LTC3887_I2C_ADDRESS 0x4F

// Global variables
static uint8_t ltc3887_i2c_address;
static LT_SMBus *smbus = new LT_SMBusNoPec();
static LT_PMBus *pmbus = new LT_PMBus(smbus);

//! Initialize Linduino
//! @return void
void setup()
{
  Serial.begin(115200);         //! Initialize the serial port to the PC
  print_title();
  ltc3887_i2c_address = LTC3887_I2C_ADDRESS;
  pmbus->disablePec(ltc3887_i2c_address);
  print_prompt();
}

//! Repeats Linduino loop
//! @return void
void loop()
{
  uint8_t user_command;
  uint8_t res;
  uint8_t model[7];
  uint8_t *addresses = NULL;

  if (Serial.available())                          //! Checks for user input
  {
    user_command = read_int();                     //! Reads the user command
    if (user_command != 'm')
      Serial.println(user_command);

    switch (user_command)                          //! Prints the appropriate submenu
    {
      case 1:
        menu_1_basic_commands();                 // Print single-ended voltage menu
        break;
      case 2:
        pmbus->readModel(ltc3887_i2c_address, model);
        Serial.print(F("MODEL "));
        Serial.print((char *)model);
        Serial.println();
        break;
      case 3:
        res = pmbus->readPmbusRevision(ltc3887_i2c_address);
        Serial.print(F("REVISION "));
        Serial.println(res, HEX);
        break;
      case 4:
        pmbus->enablePec(ltc3887_i2c_address);
        delete smbus;
        delete pmbus;
        smbus = new LT_SMBusPec();
        pmbus = new LT_PMBus(smbus);
        break;
      case 5:
        pmbus->disablePec(ltc3887_i2c_address);
        delete smbus;
        delete pmbus;
        smbus = new LT_SMBusNoPec();
        pmbus = new LT_PMBus(smbus);
        break;
      case 6:
        addresses = smbus->probe(0);
        while (*addresses != 0)
        {
          Serial.print(F("ADDR 0x"));
          Serial.println(*addresses++, HEX);
        }
        break;
      case 7 :
        pmbus->reset(ltc3887_i2c_address);
        break;
      default:
        Serial.println(F("Incorrect Option"));
        break;
    }
    print_prompt();
  }

}

// Function Definitions

//! Prints the title block when program first starts.
//! @return void
void print_title()
{
  Serial.print(F("\n*****************************************************************\n"));
  Serial.print(F("* DC1590B Demonstration Program                                 *\n"));
  Serial.print(F("*                                                               *\n"));
  Serial.print(F("* This program demonstrates how to send and receive data from   *\n"));
  Serial.print(F("* the DC1590B demo board.                                       *\n"));
  Serial.print(F("*                                                               *\n"));
  Serial.print(F("* Set the baud rate to 115200 and select the newline terminator.*\n"));
  Serial.print(F("*                                                               *\n"));
  Serial.print(F("*****************************************************************\n"));
}

//! Prints main menu.
//! @return void
void print_prompt()
{
  Serial.print(F("\n  1-Basic Commands\n"));
  Serial.print(F("  2-Model Number\n"));
  Serial.print(F("  3-Revision Number\n"));
  Serial.print(F("  4-PEC On\n"));
  Serial.print(F("  5-PEC Off\n"));
  Serial.print(F("  6-Bus Probe\n"));
  Serial.print(F("  7-Reset\n"));
  Serial.print(F("\nEnter a command:"));
}

//! Prints a warning if the demo board is not detected.
//! @return void
void print_warning_prompt()
{
  Serial.println(F("\nWarning: Demo board not detected. Linduino will attempt to proceed."));
}

//! Print all voltages
//! @return void
void print_all_voltages()
{
  float   voltage;
  uint8_t page;

  for (page = 0; page < 2; page++)
  {
    pmbus->setPage(ltc3887_i2c_address, page);
    voltage = pmbus->readVout(ltc3887_i2c_address, false);
    Serial.print(F("LTC3887 VOUT "));
    Serial.println(voltage, DEC);
  }
}

//! Print all currents
//! @return void
void print_all_currents()
{
  float   current;
  uint8_t page;

  for (page = 0; page < 2; page++)
  {
    pmbus->setPage(ltc3887_i2c_address, page);
    current = pmbus->readIout(ltc3887_i2c_address, false);
    Serial.print(F("LTC3887 IOUT "));
    Serial.println(current, DEC);
  }
}

//! Print all status bytes and words
//! @return void
void print_all_status()
{
  uint8_t b;
  uint16_t w;
  uint8_t page;

  for (page = 0; page < 2; page++)
  {
    Serial.print(F("PAGE "));
    Serial.println(page, DEC);
    pmbus->setPage(ltc3887_i2c_address, page);
//    pmbus->waitForNotBusy(ltc3887_i2c_address);
    b = pmbus->readStatusByte(ltc3887_i2c_address);
//    pmbus->waitForNotBusy(ltc3887_i2c_address);
    Serial.print(F("LTC3887 STATUS BYTE 0x"));
    Serial.println(b, HEX);
    w = pmbus->readStatusWord(ltc3887_i2c_address);
//    pmbus->waitForNotBusy(ltc3887_i2c_address);
    Serial.print(F("LTC3887 STATUS WORD 0x"));
    Serial.println(w, HEX);
  }
}

//! Sequenc off and then on
//! @return void
void sequence_off_on()
{
  pmbus->sequenceOffGlobal();
  delay (2000);
  pmbus->sequenceOnGlobal();
}

//! Margin high
//! @return void
void margin_high()
{
  pmbus->marginHighGlobal();
}

//! Margin low
//! @return void
void margin_low()
{
  pmbus->marginLowGlobal();
}

//! Go to nominal
//! @return void
void margin_off()
{
  pmbus->sequenceOnGlobal();
}

//! Display menu 1
//! @return void
void menu_1_basic_commands()
{
  uint8_t user_command;

  do
  {
    //! Displays the Read/Write menu
    Serial.print(F("\nRead/Write\n\n"));
    Serial.print(F("  1-Read All Voltages\n"));
    Serial.print(F("  2-Read All Currents\n"));
    Serial.print(F("  3-Read All Status\n"));
    Serial.print(F("  4-Sequence Off/On\n"));
    Serial.print(F("  5-Margin High\n"));
    Serial.print(F("  6-Margin Low\n"));
    Serial.print(F("  7-Margin Off\n"));
    Serial.print(F("  8-ClearFaults\n"));
    Serial.print(F("  m-Main Menu\n"));
    Serial.print(F("\nEnter a command: "));

    user_command = read_int();                              //! Reads the user command
    if (user_command == 'm')                                // Print m if it is entered
    {
      Serial.print(F("m\n"));
    }
    else
      Serial.println(user_command);                         // Print user command

    switch (user_command)
    {
      case 1:
        print_all_voltages();
        break;
      case 2:
        print_all_currents();
        break;
      case 3:
        print_all_status();
        break;
      case 4:
        sequence_off_on();
        break;
      case 5:
        margin_high();
        break;
      case 6:
        margin_low();
        break;
      case 7:
        margin_off();
        break;
      case 8:
        pmbus->clearAllFaults(ltc3887_i2c_address);
      default:
        if (user_command != 'm')
          Serial.println(F("Invalid Selection"));
        break;
    }
  }
  while (user_command != 'm');
}


Download LTC3887 - Linduino CPP File

#include "LT_PMBusDeviceLTC3887.h"

uint32_t LT_PMBusDeviceLTC3887::cap_ =  HAS_VOUT
                                        | HAS_VIN
                                        | HAS_IOUT
                                        | HAS_IIN
                                        | HAS_POUT
                                        | HAS_TEMP
                                        | HAS_DC
                                        | HAS_STATUS_WORD
                                        | HAS_STATUS_EXT
                                        ;

Download LTC3887 - Linduino Header File

/*!
LTC PSM Device

@verbatim

Representation of a device and its capabilities.

@endverbatim

REVISION HISTORY
$Revision: 3845 $
$Date: 2015-08-24 14:11:21 -0600 (Mon, 24 Aug 2015) $

Copyright (c) 2014, Linear Technology Corp.(LTC)
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

1. Redistributions of source code must retain the above copyright notice, this
   list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright notice,
   this list of conditions and the following disclaimer in the documentation
   and/or other materials provided with the distribution.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

The views and conclusions contained in the software and documentation are those
of the authors and should not be interpreted as representing official policies,
either expressed or implied, of Linear Technology Corp.

The Linear Technology Linduino is not affiliated with the official Arduino team.
However, the Linduino is only possible because of the Arduino team's commitment
to the open-source community.  Please, visit http://www.arduino.cc and
http://store.arduino.cc , and consider a purchase that will help fund their
ongoing work.
*/

/*! @file
    @ingroup LT_PMBusDevice
    Library Header File for LT_PMBusDeviceLTC3887
*/

#ifndef LT_PMBusDeviceLTC3887_H_
#define LT_PMBusDeviceLTC3887_H_

#include "LT_PMBusDeviceController.h"

class LT_PMBusDeviceLTC3887 : public LT_PMBusDeviceController
{
  public:

    static uint32_t cap_;

    LT_PMBusDeviceLTC3887(LT_PMBus *pmbus, uint8_t address) : LT_PMBusDeviceController(pmbus, address, 2)
    {
    }

    uint32_t getCapabilities (
    )
    {
      return cap_;
    }

    //! Is/are these capability(s) supported?
    //! @return true if yes
    bool hasCapability(
      uint32_t capability          //!< List of capabilities
    )
    {
      return (cap_ & capability) == capability;
    }

    static LT_PMBusDevice *detect(LT_PMBus *pmbus, uint8_t address)
    {
      uint16_t id;
      LT_PMBusDeviceLTC3887 *device;

      id = pmbus->readMfrSpecialId(address);
      if (  (id & 0xFFF0) == 0x4700)
      {
        if (pmbus->getRailAddress(address) != address)
        {
          device = new LT_PMBusDeviceLTC3887(pmbus, address);
          device->probeSpeed();
          return device;
        }
        else
          return NULL;
      }
      else
        return NULL;
    }

    uint8_t getNumPages(void)
    {
      return 2;
    }

};

#endif /* LT_PMBusDeviceLTC3887_H_ */

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