Datasheet LTC3880, LTC3880-1 (Analog Devices) - 7

LTC3880/LTC3880-1
ELECTRICAL CHARACTERISTICS The
l
denotes the specifications which apply over the specified operating junction temperature range, otherwise specifications are at TA = 25°C. (Note 2) VIN = 12V, VRUN0,1 = 3.3V, fSYNC = 500kHz (externally driven) unless otherwise specified. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V1THACC1 Threshold Accuracy 1V < VOUT1 < 2.5V Range Value = 1 l ±2 % tPROPOV1 OV Comparator to GPIO Low Time VOD = 10% of Threshold 35 µs tPROPUV1 UV Comparator to GPIO Low Time VOD = 10% of Threshold 100 µs
VIN Voltage Supervisor
N Resolution 8 bits VINRANGE Full-Scale Voltage 4.5 20 V VINSTP Step Size 82 mV VINTHACC Threshold Accuracy 9.0V < VIN < 20V l ±2.5 % VINTHACC\M Threshold Accuracy 4.5V < VIN ≤ 9V l ±5 % tPROPVIN Comparator Response Time VOD = 10% of Threshold 100 µs (VIN_ON and VIN_OFF)
Output Voltage Readback
N Resolution 16 Bits LSB Step Size 244 µV VOFS Full-Scale Voltage (Note 10) VRUNn = 0V (Note 8) 8 V VOUT_TUE Total Unadjusted Error (Note 8) VOUTn > 0.6V l 0.5 % VOS Zero-Code Offset Voltage ±500 µV tCONVERT Conversion Time (Note 6) 90 ms
VIN Voltage Readback
N Resolution (Note 5) 10 Bits VIFS Full-Scale Voltage (Note 11) 38.91 V VIN_TUE Total Unadjusted Error VVIN > 4.5V (Note 8) 0.5 % l 2 % tCONVERT Conversion Time (Note 6) 90 ms
Output Current Readback
N Resolution (Note 5) 10 Bits LSB Step Size 0V ≤ |V + – ISENSE – VISENSE | < 16mV 15.625 µV 16mV ≤ |V + – ISENSE – VISENSE | < 32mV 31.25 µV 32mV ≤ |V + – ISENSE – VISENSE | < 63.9mV 62.5 µV 63.9mV ≤ |V + – ISENSE – VISENSE | < 127.9mV 125 µV IFS Full-Scale Current (Note 7) RISENSE = 1mΩ ±128 A IOUT_TUE Total Unadjusted Error (Note 8) VISENSE > 6mV (Note 15) l ±1 % VOS Zero-Code Offset Voltage ±28 µV tCONVERT Conversion Time (Note 6) 90 ms
Input Current and Duty Cycle Readback
D_RES Resolution 10 Bits D_TUE Total Unadjusted Error 16.3% Duty Cycle –3 3 % tCONVERT Update Rate (Note 6) 90 ms Rev. H For more information www.analog.com 7 Document Outline Features Applications Typical Application Description Table of Contents Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Overview Main Control Loop EEPROM Power Up and Initialization Soft-Start Sequencing Voltage-Based Sequencing Shutdown Light Load Current Operation Switching Frequency and Phase Output Voltage Sensing Current Sensing Load Sharing External/Internal Temperature Sense RCONFIG (Resistor Configuration) Pins Fault Detection and Handling Internal Memory with CRC and ECC Serial Interface Communication Failure Device Addressing Responses to VOUT and IOUT Faults Output Overvoltage Fault Response Output Undervoltage Response Peak Output Overcurrent Fault Response Responses to Timing Faults Responses to VIN OV Faults Responses to OT/UT Faults Overtemperature Fault Response—Internal Overtemperature and Undertemperature Fault Response—Externals Responses to External Faults Bus Timeout Failure Similarity Between PMBus, SMBus and I2C 2-Wire Interface PMBus Serial Digital Interface PMBus Command Summary PMBus Commands *Data Format Applications Information Current Limit Programming ISENSE+ and ISENSE– Pins Low Value Resistor Current Sensing Inductor DCR Current Sensing Slope Compensation and Inductor Peak Current Inductor Value Calculation Inductor Core Selection Power MOSFET and Schottky Diode (Optional) Selection Variable Delay Time, Soft-Start and Output Voltage Ramping Digital Servo Mode Soft Off (Sequenced Off) INTVCC Regulator Topside MOSFET Driver Supply (CB, DB) Undervoltage Lockout CIN and COUT Selection Fault Conditions Open-Drain Pins Phase-Locked Loop and Frequency Synchronization Minimum On-Time Considerations RCONFIG (External Resistor Configuration Pins) Voltage Selection Frequency and Phase Selection Using RCONFIG Address Selection Using RCONFIG Efficiency Considerations Checking Transient Response PC Board Layout Checklist PC Board Layout Debugging Design Example Connecting the USB to the I2C/SMBus/PMBus Controller to the LTC3880 In System LTpowerPlay: An Interactive GUI for Digital Power PMBus Communication and Command Processing PMBus Command Details Addressing and Write Protect General Configuration Registers On/Off/Margin PWM Config Voltage Input Voltage and Limits Output Voltage and Limits Current Input Current Calibration Output Current Calibration Input Current Output Current Temperature External Temperature Calibration External Temperature Limits Timing Timing—On Sequence/Ramp Timing—Off Sequence/Ramp Precondition for Restart Fault Response Fault Responses All Faults Fault Responses Input Voltage Fault Responses Output Voltage Fault Responses Output Current Fault Responses IC Temperature Fault Responses External Temperature Fault Sharing Fault Sharing Propagation Fault Sharing Response Scratchpad Identification Fault Warning and Status Telemetry NVM Memory Commands Store/Restore Fault Log Operation Fault Logging Block Memory Write/Read Typical Applications Package Description Revision History Typical Application Related Parts