DESCRIPTION

The LTM4680 is a dual 30A or single 60A step-down µModule (power module) DC/DC regulator featuring remote configurability and telemetry-monitoring of power management parameters over PMBus—an open standard I2C-based digital interface protocol. The LTM4680 is comprised of digitally programmable analog control loops, precision mixed-signal circuitry, EEPROM, power MOSFETs, inductors and supporting components.

The LTM4680 product video is available on the website. The LTM4680’s 2-wire serial interface allows outputs to be margined, tuned and ramped up and down at programmable slew rates with sequencing delay times. True input current sense, output currents and voltages, output power, temperatures, uptime and peak values are readable. Custom configuration of the EEPROM contents is not required. At start-up, output voltages, switching frequency, and channel phase angle assignments can be set by pinstrapping resistors. The LTpowerPlay GUI and DC1613A USB-to-PMBus converter and demo kits are available.

The LTM4680 is offered in a 16mm × 16mm × 7.82mm BGA package available with SnPb or RoHS compliant terminal finish. Pin compatible with LTM4678.

 

FEATURES

Dual 30A or Single 60A Digitally Adjustable Analog Loops with Digital Interface for Control and Monitoring

Wide Input Voltage Range: 4.5V to 16V

Output Voltage Range: 0.5V to 3.3V

90% Full Load Efficiency from 12VIN to 1VOUT at 60A

±0.5% Maximum DC Output Error Over Temperature

±2.5% Current Readback Accuracy (25°C to 125°C)

Integrated Input Current Sense Amplifier

400kHz PMBus-Compliant I2C Serial Interface

Supports Telemetry Polling Rates Up to 125Hz

Constant Frequency Current Mode Control

Parallel and Current Share Multiple Modules

Pin Compatible with LTM4678

16mm × 16mm × 7.82mm BGA Package

 

Readable Data

Input and Output Voltages, Currents, and Temperatures

Running Peak Values, Uptime, Faults and Warnings

Onboard EEPROM Fault Log Record

 

Writable Data and Configurable Parameters

Output Voltage, Voltage Sequencing and Margining

Digital Soft-Start/ Soft-Stop Ramp, Program Analog Loop

OV/UV/OT, UVLO, Frequency and Phasing

 

APPLICATIONS

System Optimization, Characterization and Data Mining in Prototype, Production and Field Environments

 

OPERATION

POWER MODULE INTRODUCTION

The LTM4680 is a highly configurable dual 30A output standalone nonisolated switching mode step-down DC/DC power supply with built-in EEPROM NVM (non-volatile memory) with ECC and I2C-based PMBus/ SMBus 2-wire serial communication interface capable of 400kHz SCL bus speed. Two output voltages can be regulated (VOUT0, VOUT1—collectively, VOUTn) with a few external input and output capacitors and pull-up resistors. Readback telemetry data of input and output voltages and input and output currents, and module temperatures are continually digitized cyclically by an integrated 16-bit ADC (analog-to-digital converter). Many fault thresholds and responses are customizable. Data can be autonomously saved to EEPROM when a fault occurs, and the resulting fault log can be retrieved over I2C at a later time, for analysis. See Figure 2 and Figure 3 for Block Diagrams.

 

POWER MODULE OVERVIEW, MAJOR FEATURES

Major Features Include:
Dedicated Power Good Indicators
Direct Input and Chip Current Sensing
Programmable Loop Compensation Parameters
TINIT Start-Up Time: 30ms
PWM Synchronization Circuit, (See Frequency and Phasing Section for Details)
MFR_ADC_CONTROL for Fast ADC Sampling of One Parameter (as Fast as 8ms) (See PMBus Command for Details)
Fully Differential Output Sensing for Both Channels; VOUT0/VOUT1 Both Programmable Up to 3.6V
Power-Up and Program EEPROM with EXTVCC
Input Voltage Up to 16V
∆VBE Temperature Sensing
SYNC Contention Circuit (Refer to Frequency and Phase Section for Details)
Fault Logging
Programmable Output Voltage
Programmable Input Voltage On and Off Threshold Voltage
Programmable Current Limit
Programmable Switching Frequency
Programmable OV and UV Threshold voltage
Programmable On and Off Delay Times
Programmable Output Rise/Fall Times
Phase-Locked Loop for Synchronous PolyPhase Operation (2, 3, 4 or 6 Phases)
Nonvolatile Configuration Memory with ECC
Optional External Configuration Resistors for Key Operating Parameters
Optional Time Base Interconnect for Synchronization Between Multiple Controllers
WP Pin to Protect Internal Configuration
Standalone Operation after User Factory Configuration
PMBus, Version 1.2, 400kHz Compliant Interface The PMBus interface provides access to important power management data during system operation including:
Internal Controller Temperature
Internal Power Channel Temperature Average Output Current
Average Output Voltage
Average Input Voltage
Average Input Current
Average Chip Input Current from VIN
Configurable, Latched and Unlatched Individual Fault and Warning Status