80V Synchronous 4-Switch Buck-Boost DC/DC Slave Controller for LT8708 Multiphase System Features: Slave Chip of LT8708 to Deliver Additional Power Good Current Matching to the Average Output Current of LT8708 Through Current Regulation Easily Paralleled with LT8708 Through Four Pins Synchronized Start-Up with LT8708 Same Conduction Modes as LT8708 Synchronous Rectification: Up to 98% Efficiency Frequency Range: 100kHz to 400kHz Available in 40-Lead (5mm × 8mm) QFN with High Voltage Pin Spacing and 64-Lead (10mm × 10mm) eLQFP AEC-Q100 in Progress

Negative Input Synchronous Multi-Topology DC/DC Controller Features: Wide Negative Input Range: –4.5V to –80V Rail-to-Rail Output Current Monitor and Control Input Voltage Regulation for High Impedance Inputs Power Good Indication Pin MODE Pin for Forced CCM (Continuous Conduction Mode) or Pulse-Skipping/DCM (Discontinuous Conduction Mode) Operation Switching Frequency Up to 750kHz Easily Configurable as a Buck, Boost, Buck-Boost, or Inverting Converter with a Single Feedback Pin Can be Synchronized to an External Clock High Gain EN/FBIN Pin Accepts Slowly Varying Input Signals 20-Lead TSSOP Package

Synchronous SEPIC/Inverting/Boost Controller with Output Current Control Features: Wide Input Range: 4.5V to 80V Rail-to-Rail Output Current Monitor and Control Input Voltage Regulation for High Impedance Inputs C/10 or Power Good Indication Pin MODE Pin for Forced CCM or Pulse-Skipping Operation Switching Frequency Up to 750kHz Easily Configurable as a Boost, SEPIC, Inverting or Flyback Converter with Single Feedback Pin Can Be Synchronized to External Clock High Gain EN/FBIN Pin Accepts Slowly Varying Input Signals 20-Lead TSSOP Package

Supervisory Circuits VOLTAGE DETECTOR

LDO Voltage Regulators Linear LDO reg Hi 9A Iq 150mA Iout

Supervisory Circuits Voltage Detector 0.35uA Iq

Negative 48V Hot Swap Controller Features: Allows Safe Board Insertion and Removal from a Live –48V Backplane Circuit Breaker Immunity to Voltage Steps and Current Spikes Programmable Inrush and Short-Circuit Current Limits Pin Compatible with LT1640L/LT1640H Operates from –18V to –80V Programmable Overvoltage Protection Programmable Undervoltage Lockout Power Good Control Output Bell-Core Compatible ON/OFF Threshold

Positive High Voltage Hot Swap Controller with Open-Circuit Detect Features: Allows Safe Board Insertion and Removal from a Live Backplane Controls Supply Voltage from 10.8V to 80V Foldback Current Limiting Open Circuit and Overcurrent Fault Detect Drives an External N-Channel MOSFET Automatic Retry or Latched Off Operation After Overcurrent Fault Programmable Supply Voltage Power-Up Rate Open MOSFET Detection 1% Over and Undervoltage Detection Accuracy Available in a 16-Lead SSOP Package

IEEE 802.3bt PD Interface Controller Features: IEEE 802.3af/at/bt Powered Device (PD) Controller Supports Up to 71.3W PDs 5-Event Classification Sensing Superior Surge Protection (100V Absolute Maximum) Wide Junction Temperature Range (–40°C to 125°C) Overtemperature Protection Integrated Signature Resistor External Hot Swap N-Channel MOSFET for Lowest Power Dissipation and Highest System Efficiency Configurable Aux Power Support as Low as 9V Easy Migration Between LTPoE++® PDs and IEEE 802.3bt PDs Pin Compatible with LT4275A/B/C Available in 10-Lead MSOP and 3mm × 3mm DFN Packages

Secondary-Side Optocoupler Driver Features: 600mV Reference (1.25% Over Temperature) Wide Input Supply Range: 3V to 20V Overshoot Control Function Prevents Output Overshoot on Start-Up and Short-Circuit Recovery High Bandwidth Error Amplifier Permits Simple Loop Frequency Compensation Ground-Referenced Opto-Coupler Drive 10mA Opto-Coupler Drive with Current Limiting Low Profile (1mm) ThinSOT™ Package