Datasheet LTC7810 (Analog Devices)
| Manufacturer | Analog Devices |
| Description | 150V Low IQ, Dual, 2-Phase Synchronous Step-Down DC/DC Controller with PassThru |
| Pages / Page | 42 / 1 — FEATURES. DESCRIPTION. Wide VIN Range: 4.5V to 140V (150V Abs Max). Wide … |
| Revision | A |
| File Format / Size | PDF / 4.0 Mb |
| Document Language | English |
FEATURES. DESCRIPTION. Wide VIN Range: 4.5V to 140V (150V Abs Max). Wide Output Voltage Range: 1V ≤ VOUT ≤ 60V
Model Line for this Datasheet
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LTC7810 150V Low IQ, Dual, 2-Phase Synchronous Step-Down DC/DC Controller
FEATURES DESCRIPTION
n
Wide VIN Range: 4.5V to 140V (150V Abs Max)
The LTC®7810 is a high performance dual step-down DC/ n
Wide Output Voltage Range: 1V ≤ VOUT ≤ 60V
DC switching regulator controller that drives all N-channel n
Low Operating IQ: 16μA (48VIN to 12VOUT and 3.3VOUT)
synchronous power MOSFET stages that can operate n
Adjustable Gate Drive Level Up to 10V
from voltages up to 140V. A constant frequency current n
Optional Spread Spectrum Operation
mode architecture allows a phase-lockable frequency of n
Very Low Dropout: 100% Duty Cycle Operation
up to 720kHz. n Low IQ in Dropout: 78µA (One Channel On) The low no-load quiescent current extends operating run n RSENSE or Inductor DCR Current Sensing time in battery-powered systems. The LTC7810 features n Out-of-Phase Controllers Reduce Required Input a precision 1V reference, enabling the output voltage to Capacitance and Power Supply Induced Noise be programmed from 1V to 60V. The gate drive voltage n Phase-Lockable Frequency (75kHz to 720kHz) for the LTC7810 can be programmed to 6V, 8V, or 10V n Programmable Fixed Frequency (50kHz to 750kHz) to allow the use of logic-level or standard-threshold FETs n Selectable Continuous, Pulse-Skipping, or Low Ripple and to maximize efficiency. Burst Mode® Operation at Light Loads n Onboard LDO or External NMOS LDO for DRV The LTC7810 additionally features spread spectrum oper- CC n EXTV ation which significantly reduces the peak radiated and CC LDO Powers Drivers from VOUT n Programmable Input Overvoltage Lockout conducted noise on both the input and output supplies, n 48-Lead (7mm × 7mm) eLQFP Package making it easier to comply with electromagnetic interfer- ence (EMI) standards.
APPLICATIONS
All registered trademarks and trademarks are the property of their respective owners. n Automotive and Transportation n Industrial and Telecommunications n Military/Avionics
TYPICAL APPLICATION High Efficiency Dual 12V/5V Output Step-Down Regulator with Spread Spectrum Efficiency and Power Loss
V DRV IN CC 12.5V to 140V
vs Load Current
2.2µF RUN1 VIN RUN2 DRVCC 100 100 BOOST1 BOOST2 VOUT = 12V TG1 TG2 10µH 0.1µF 0.1µF 33µH 10 SW1 SW2 90 LTC7810 EFFICIENCY POWER LOSS (W) BG1 BG2 80 1 POWER LOSS SENSE1+ SENSE2+ 8mΩ 10mΩ 70 0.1 SENSE1– SENSE2– V V EFFICIENCY (%) OUT1 OUT2 EXTVCC 5V/6A 12V/5A 220k 22pF 220k 470µF 150µF 60 0.01 VFB1 VFB2 VIN = 24V ITH1 ITH2 V TRACK/SS1 TRACK/SS2 IN = 72V 55k 20k DRVSET VIN = 140V NDRV DRVCC 50 0.001 0.1µF INTV 17.4k CC MODE 12.1k PLLIN/SPREAD REGSD 0.001 0.01 0.1 1 10 0.1µF OVLO GND FREQ LOAD CURRENT (A) 1.5nF 1.5nF 0.1µF 7810 TA01b 7810 TA01a Rev. A Document Feedback For more information www.analog.com 1 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Functional Diagram Operation Main Control Loop Power and Bias Supplies (VIN, NDRV, EXTVCC, DRVCC, REGSD) Boost Supply and Dropout (BOOST and SW pins) Start-Up and Shutdown (RUN, TRACK/SS, OVLO Pins) Light Load Operation: Burst Mode Operation, Pulse Skipping or Forced Continuous Mode (MODE Pin) Frequency Selection, Spread Spectrum, and Phase-Locked Loop (FREQ and PLLIN/SPREAD Pins) Applications Information Current Sense Selection Low Value Resistor Current Sensing Inductor DCR Sensing Setting the Operating Frequency Selecting the Light-Load Operating Mode Inductor Value Calculation Inductor Core Selection Power MOSFET Selection CIN and COUT Selection Setting the Output Voltage RUN Pins and Overvoltage/Undervoltage Lockout Tracking and Soft-Start (TRACK/SS1, TRACK/SS2 Pins) Single Output Two-Phase Operation DRVCC Regulators Topside MOSFET Driver Supply (CB, DB) Burst Clamp Programming Fault Conditions: Current Limit and Current Foldback Fault Conditions: Overvoltage Protection (Crowbar) Fault Conditions: Overtemperature Protection Phase-Locked Loop and Frequency Synchronization Minimum On-Time Considerations Efficiency Considerations Checking Transient Response Design Example PC Board Layout Checklist PC Board Layout Debugging Typical Applications Package Description Revision History Typical Application Related Parts
FEATURES DESCRIPTION
n
Wide VIN Range: 4.5V to 140V (150V Abs Max)
The LTC®7810 is a high performance dual step-down DC/ n
Wide Output Voltage Range: 1V ≤ VOUT ≤ 60V
DC switching regulator controller that drives all N-channel n
Low Operating IQ: 16μA (48VIN to 12VOUT and 3.3VOUT)
synchronous power MOSFET stages that can operate n
Adjustable Gate Drive Level Up to 10V
from voltages up to 140V. A constant frequency current n
Optional Spread Spectrum Operation
mode architecture allows a phase-lockable frequency of n
Very Low Dropout: 100% Duty Cycle Operation
up to 720kHz. n Low IQ in Dropout: 78µA (One Channel On) The low no-load quiescent current extends operating run n RSENSE or Inductor DCR Current Sensing time in battery-powered systems. The LTC7810 features n Out-of-Phase Controllers Reduce Required Input a precision 1V reference, enabling the output voltage to Capacitance and Power Supply Induced Noise be programmed from 1V to 60V. The gate drive voltage n Phase-Lockable Frequency (75kHz to 720kHz) for the LTC7810 can be programmed to 6V, 8V, or 10V n Programmable Fixed Frequency (50kHz to 750kHz) to allow the use of logic-level or standard-threshold FETs n Selectable Continuous, Pulse-Skipping, or Low Ripple and to maximize efficiency. Burst Mode® Operation at Light Loads n Onboard LDO or External NMOS LDO for DRV The LTC7810 additionally features spread spectrum oper- CC n EXTV ation which significantly reduces the peak radiated and CC LDO Powers Drivers from VOUT n Programmable Input Overvoltage Lockout conducted noise on both the input and output supplies, n 48-Lead (7mm × 7mm) eLQFP Package making it easier to comply with electromagnetic interfer- ence (EMI) standards.
APPLICATIONS
All registered trademarks and trademarks are the property of their respective owners. n Automotive and Transportation n Industrial and Telecommunications n Military/Avionics
TYPICAL APPLICATION High Efficiency Dual 12V/5V Output Step-Down Regulator with Spread Spectrum Efficiency and Power Loss
V DRV IN CC 12.5V to 140V
vs Load Current
2.2µF RUN1 VIN RUN2 DRVCC 100 100 BOOST1 BOOST2 VOUT = 12V TG1 TG2 10µH 0.1µF 0.1µF 33µH 10 SW1 SW2 90 LTC7810 EFFICIENCY POWER LOSS (W) BG1 BG2 80 1 POWER LOSS SENSE1+ SENSE2+ 8mΩ 10mΩ 70 0.1 SENSE1– SENSE2– V V EFFICIENCY (%) OUT1 OUT2 EXTVCC 5V/6A 12V/5A 220k 22pF 220k 470µF 150µF 60 0.01 VFB1 VFB2 VIN = 24V ITH1 ITH2 V TRACK/SS1 TRACK/SS2 IN = 72V 55k 20k DRVSET VIN = 140V NDRV DRVCC 50 0.001 0.1µF INTV 17.4k CC MODE 12.1k PLLIN/SPREAD REGSD 0.001 0.01 0.1 1 10 0.1µF OVLO GND FREQ LOAD CURRENT (A) 1.5nF 1.5nF 0.1µF 7810 TA01b 7810 TA01a Rev. A Document Feedback For more information www.analog.com 1 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Functional Diagram Operation Main Control Loop Power and Bias Supplies (VIN, NDRV, EXTVCC, DRVCC, REGSD) Boost Supply and Dropout (BOOST and SW pins) Start-Up and Shutdown (RUN, TRACK/SS, OVLO Pins) Light Load Operation: Burst Mode Operation, Pulse Skipping or Forced Continuous Mode (MODE Pin) Frequency Selection, Spread Spectrum, and Phase-Locked Loop (FREQ and PLLIN/SPREAD Pins) Applications Information Current Sense Selection Low Value Resistor Current Sensing Inductor DCR Sensing Setting the Operating Frequency Selecting the Light-Load Operating Mode Inductor Value Calculation Inductor Core Selection Power MOSFET Selection CIN and COUT Selection Setting the Output Voltage RUN Pins and Overvoltage/Undervoltage Lockout Tracking and Soft-Start (TRACK/SS1, TRACK/SS2 Pins) Single Output Two-Phase Operation DRVCC Regulators Topside MOSFET Driver Supply (CB, DB) Burst Clamp Programming Fault Conditions: Current Limit and Current Foldback Fault Conditions: Overvoltage Protection (Crowbar) Fault Conditions: Overtemperature Protection Phase-Locked Loop and Frequency Synchronization Minimum On-Time Considerations Efficiency Considerations Checking Transient Response Design Example PC Board Layout Checklist PC Board Layout Debugging Typical Applications Package Description Revision History Typical Application Related Parts
