I (A) CHANNEL 1 TEMP (C) IN1 V (V) OUT1 I (A) OUT1 LTM4677 Dual 18A or Single 36A Module Regulator with Digital Power System Management FEATURES DESCRIPTION n Dual, Fast, Analog Loops with Digital Interface The LTM 4677 is a dual 18A or single 36A step-down for Control and Monitoring Module (power module) DC/DC regulator with 40ms n Wide Input Voltage Range: 4.5V to 16V turn-on time. It features remote configurability and n Output Voltage Range: 0.5V to 1.8V telemetry-monitoring of power management parameters 2 n 0.5% Maximum DC Output Error Over Temperature over PMBus an open standard I C-based digital inter- n 2.5% Current Readback Accuracy face protocol. The LTM4677 is comprised of fast analog n Pin Compatible with LTM4676A (Dual 13A, Single 26A) control loops, precision mixed-signal circuitry, EEPROM, 2 n 400kHz PMBus-Compliant I C Serial Interface power MOSFETs, inductors and supporting components. n Supports Telemetry Polling Rates up to 125Hz The LTM4677s 2-wire serial interface allows outputs to n Integrated 16-Bit ADC be margined, tuned and ramped up and down at program- n Constant Frequency Current Mode Control mable slew rates with sequencing delay times. Input and n Parallel and Current Share Multiple Modules output currents and voltages, output power, temperatures, n 16mm 16mm 5.01mm BGA Package uptime and peak values are readable. Custom configura- Readable Data: tion of the EEPROM contents is not required. At start-up, n Input and Output Voltages, Currents, and Temperatures output voltages, switching frequency, and channel phase n Running Peak Values, Uptime, Faults and Warnings angle assignments can be set by pin-strapping resistors. n Onboard EEPROM Fault Log Record with ECC The LTpowerPlay GUI and DC1613 USB-to-PMBus con- Writable Data and Configurable Parameters: verter and demo kits are available. n Output Voltage, Voltage Sequencing and Margining The LTM4677 is pin compatible with the LTM4676A n Digital Soft-Start/Stop Ramp (dual 13A) and is offered in a 16mm 16mm 5.01mm n OV/UV/OT, UVLO, Frequency and Phasing BGA package available with SnPb or RoHS compliant APPLICATIONS terminal finish. n System Optimization, Characterization and All registered trademarks and trademarks are the property of their respective owners. Protected by U.S. Patents including 5408150, 5481178, 5705919, 5929620, 6144194, 6177787, 6580258, Data Mining in Prototype, Production and Field 7420359, 8163643. Licensed under U.S. Patent 7000125 and other related patents worldwide. Environments n Telecom, Datacom, and Storage Systems Using PMBus and LTpowerPlay to Monitor Telemetry and Margin TYPICAL APPLICATION V /V During Load Pattern Tests. 10Hz Polling Rate. 12V OUT0 OUT1 IN Dual 18A Module Regulator with Digital Output Voltage Readback, V Margined 7.5% Low Input Current Readback OUT Interface for Control and Monitoring* 1.1 1.9 1.5 2.4 V , OUT0 V IN V V ADJUSTABLE 1.0 1.8 1.0 1.6 IN0 OUT0 5.75V TO 16V 22F V UP TO 18A IN1 + V OSNS0 4 100F 0.9 1.7 0.5 0.8 SV IN LOAD 6 0 RUN 0 0.8 1.6 0 0 ON/OFF CONTROL V OSNS0 RUN 0 3 6 9 12 0 3 6 9 12 1 V , LTM4677 OUT1 TIME (SEC) 4677 TA01b TIME (SEC) 4677 TA01d V ADJUSTABLE OUT1 FAULT INTERRUPTS, GPIO UP TO 18A 0 V OSNS1 Output Current Readback, Varying Load Pattern Power Stage Temperature Readback POWER SEQUENCING GPIO 1 100F 15 15 60 60 LOAD 6 1 PWM CLOCK AND SYNC SGND TIME-BASE 10 10 57 57 SHARE CLK SYNCHRONIZATION 2 SCL I C/SMBus I/F WITH 5 5 54 54 SDA PMBus COMMAND SET REGISTER WRITE WP ALERT GND TO/FROM IPMI OR OTHER PROTECTION 0 0 51 51 4677 TA01a BOARD MANAGEMENT 0 3 6 9 12 0 3 6 9 12 CONTROLLER TIME (SEC) 4677 TA01c TIME (SEC) 4677 TA01e *FOR COMPLETE CIRCUIT, SEE FIGURE 56 Rev. B 1 Document Feedback For more information www.analog.com V (V) I (A) OUT0 OUT0 CHANNEL 0 TEMP (C) I (A) IN0LTM4677 TABLE OF CONTENTS Features ..................................................... 1 PMBus Command Summary ............................ 41 Applications ................................................ 1 PMBus Commands ................................................ 41 Typical Application ........................................ 1 Applications Information ................................ 48 Description.................................................. 1 V to V Step-Down Ratios ................................50 IN OUT Absolute Maximum Ratings .............................. 4 Input Capacitors ..................................................... 51 Order Information .......................................... 4 Output Capacitors ................................................... 51 Pin Configuration .......................................... 4 Light Load Current Operation ................................. 51 Electrical Characteristics ................................. 5 Switching Frequency and Phase .............................52 Typical Performance Characteristics .................. 12 Minimum On-Time Considerations..........................53 Pin Functions .............................................. 15 Variable Delay Time, Soft-Start and Output Simplified Block Diagram ............................... 20 Voltage Ramping ....................................................54 Decoupling Requirements ............................... 20 Digital Servo Mode .................................................55 Functional Diagram ...................................... 21 Soft Off (Sequenced Off) ........................................56 Test Circuits ............................................... 22 Undervoltage Lockout .............................................56 Operation................................................... 23 Fault DETECTION AND HANDLING .........................56 Power Module Introduction ....................................23 Open-Drain Pins .....................................................57 Power Module Configurability and Phase-Locked Loop and Frequency Readback Data ........................................................25 Synchronization ......................................................58 Time-Averaged and Peak Readback Data ................28 RCONFIG Pin-Straps (External Resistor Power Module Overview .........................................31 Configuration Pins) .................................................58 EEPROM .................................................................35 Voltage Selection ....................................................59 2 Serial Interface .......................................................36 Connecting the USB to the I C/SMBus/PMBus Device Addressing ..................................................36 Controller to the LTM4677 In System .....................59 Fault Detection and Handling ..................................37 PMBus Communication and Command Responses to V and I Faults ........................38 Processing ..............................................................63 OUT OUT Responses to Timing Faults ....................................39 Thermal Considerations and Responses to SV OV Faults ..................................39 Output Current Derating .........................................64 IN Responses to OT/UT Faults .....................................39 Applications Information-Derating Curves ............ 69 Responses to External Faults .................................40 EMI Performance ....................................................71 Fault Logging ..........................................................40 Safety Considerations .............................................71 Bus Timeout Protection ..........................................40 Layout Checklist/Example ......................................71 Rev. B 2 For more information www.analog.com