Datasheet LTC3887, LTC3887-1, LTC3887-2 (Analog Devices) - 6

LTC3887/LTC3887-1/ LTC3887-2
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 Input Voltage
VIN Input Voltage Range LTC3887, LTC3887-1 (Note 12) l 4.5 24 V VIN Input Voltage Range LTC3887-2 (Note 12) l 4.5 34 V IQ Input Voltage Supply Current (Note 14) Normal Operation VRUN0,1 = 3.3V, No Caps on TG and BG 25 mA VRUN0,1 = 0V 20 mA VUVLO Undervoltage Lockout Threshold VINTVCC Falling 3.7 V when VIN > 4.3V VINTVCC Rising 3.95 V TINIT Initialization Time Time from VIN Applied Until the TON_DELAY 30 ms Timer Starts.
Control Loop
VOUTR0 Full-Scale Voltage High Range VOUT_COMMAND = 5.500V (Note 9) l 5.45 5.55 V Set Point Accuracy (0.6V to 5V) l –0.5 0.5 % Resolution 12 Bits LSB Step Size 1.375 mV VOUTR1 Full-Scale Voltage Low Range VOUT_COMMAND = 2.75V (Note 9) l 2.7 2.8 V Set Point Accuracy (0.6V to 2.5V) l –0.5 0.5 % Resolution 12 Bits LSB Step Size 0.6875 mV VLINEREG Line Regulation 6V < VIN < 24V l ±0.02 %/V VLOADREG Load Regulation ∆VITH = 1.35V – 0.7V l 0.01 0.1 % ∆VITH = 1.35V – 2.0V l –0.01 –0.1 % gm0,1 Error Amplifier gm ITH0,1 =1.22V 3 mmho IISENSE0,1 Input Current VISENSE = 5.5V l ±1 ±3 µA VSENSERIN0 VSENSE Input Resistance to Ground 0V ≤ VPIN ≤ 5.5V 41 kΩ VSENSERIN1 VSENSE Input Resistance to Ground 0V ≤ VPIN ≤ 5.5V 37 kΩ VIlLIMIT Resolution 3 bits VILIMMAX Hi Range l 68 75 82 mV Lo Range l 44 50 56 mV VILMMIN Hi Range 37.5 mV Lo Range 25 mV
Gate Drivers LTC3887
TG0,1 TG Transition Time (LTC3887/LTC3887-1) (Note 4) tr Rise Time CLOAD = 3300pF 30 ns tf Fall Time CLOAD = 3300pF 30 ns BG0,1 BG Transition Time: (Note 4) tr Rise Time CLOAD = 3300pF 30 ns tf Fall Time CLOAD = 3300pF 30 ns TG/BG t1D Top Gate Off to Bottom Gate On Delay Time (Note 4) CLOAD = 3300pF Each Driver 30 ns BG/TG t2D Bottom Gate Off to Top Gate On Delay Time (Note 4) CLOAD = 3300pF Each Driver 30 ns tON(MIN) Minimum On-Time (LTC3887/LTC3887-1) 45 ns
OV Output Voltage Supervisor
N Resolution 8 Bits VRANGE0 Voltage Monitoring Range Range Value = 0 1 5.6 V VRANGE1 Voltage Monitoring Range Range Value = 1 0.5 2.7 V VOUSTP0 Threshold Programming Step Range Value = 0 22.5 mV VOUSTP1 Threshold Programming Step Range Value = 1 11.25 mV VTHACC0 Threshold Accuracy 2V < VOUT < 5V Range Value = 0 l ±2 % VTHACC1 Threshold Accuracy 1V < VOUT < 2.5V Range Value = 1 l ±2 % tPROPOV OV Comparator to GPIO Low Time VOD = 10% of Threshold 35 µs Rev.F 6 For more information www.analog.com 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 (NVM) Power Up and Initialization Soft-Start Sequencing EVENT-Based Sequencing Shutdown Light Load Current Operation Switching Frequency and Phase Output Voltage Sensing Current Sensing PolyPhase Load Sharing External/Internal Temperature Sense RCONFIG (Resistor Configuration) Pins Fault Detection and Handling Internal EEPROM with CRC Protection and ECC Serial Interface Communication Protection 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 Internal Overtemperature Fault/Warn Response External Overtemperature and Undertemperature Fault Response Responses to External Faults Fault Logging Bus Timeout Protection 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) (LTC3887, LTC3887-2) 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 Additional Design Checks Connecting the USB to the I2C/SMBus/PMBus Controller to the LTC3887 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 (EEPROM) Memory Commands Store/Restore Fault Logging Block Memory Write/Read Typical Applications Package Description Revision History Typical Application Related Parts