FAN7688SJX ON Semiconductor

DATA SHEET www.onsemi.com Advanced Secondary Side LLC Resonant Converter Controller with Synchronous SOP16 Rectifier Control CASE 565BF FAN7688 MARKING DIAGRAM Description The FAN7688 is an advanced Pulse Frequency Modulated (PFM) Y&Z&2&K controller for LLC resonant converters with Synchronous FAN7688 Rectification (SR) that offers best in class efficiency for isolated DC/DC converters. It employs a current mode control technique based on a charge control, where the triangular waveform from the oscillator is combined with the integrated switch current information to FAN7688 = Device Code determine the switching frequency. This provides a better Y = Logo controltooutput transfer function of the power stage simplifying the &Z = Assembly Plant Code feedback loop design while allowing true input power limit capability. &2 = 2Digit Date Code &K = 2Digits Lot Run Traceability Code Closedloop softstart prevents saturation of the error amplifier and allows monotonic rising of the output voltage regardless of load condition. A dual edge tracking adaptive dead time control minimizes ORDERING INFORMATION the body diode conduction time thus maximizing efficiency. See detailed ordering and shipping information on page 30 of this data sheet. Features Secondary Side PFM Controller for LLC Resonant Converter with Applications Synchronous Rectifier Control Desktop ATX, DesktopDerived Server, Charge Current Control for Better Transient Response and Easy Blade Feedback Loop Design Server, and Telecom Power Supplies Adaptive Synchronous Rectification Control with Dual Edge Intelligent 100 W 2 kW + OffLine Power Tracking Supplies Closed Loop SoftStart for Monotonic Rising Output High Efficiency Isolated DCDC Converters Wide Operating Frequency (39 kHz~690 kHz) Large Screen Display Power Green Functions to Improve LightLoad Efficiency Industrial Power Symmetric PWM Control at LightLoad to Limit the Switching Frequency while Reducing Switching Losses Disabling SR at LightLoad Condition Protection Functions with AutoRestart OverCurrent Protection (OCP) Output Short Protection (OSP) NON ZeroVoltage Switching Prevention (NZS) by Compensation Cutback (Frequency Shift) Power Limit by Compensation Cutback (Frequency Shift) Overload Protection (OLP) with Programmable Shutdown Delay Time OverTemperature Protection (OTP) Programmable Dead Times for Primary Side Switches and Secondary Side Synchronous Rectifiers V UnderVoltage Lockout (UVLO) DD Wide Operating Temperature Range 40C to +125C Semiconductor Components Industries, LLC, 2015 1 Publication Order Number: August, 2021 Rev. 3 FAN7688/DFAN7688 PIN CONFIGURATION 5VB GND 1 16 PWMS VDD 2 15 PROUT1 FMIN 3 14 FB PROUT2 4 13 COMP SROUT1 5 12 SS 6 11 SROUT2 ICS SR1DS 7 10 CS RDT 89 Figure 1. Pin Assignment THERMAL IMPEDANCE Symbol Parameter Value Unit JunctiontoAmbient Thermal Impedance 102 C/W JA PIN DEFINITIONS Pin No. Name Pin Description 1 5VB 5 V REF 2 PWMS PWM mode entry level setting. 3 FMIN Minimum frequency setting pin. 4 FB Output voltage sensing for feedback control. 5 COMP Output of error amplifier. 6 SS Softstart time programming pin. 7 ICS Current information integration pin for current mode control. 8 CS Current sensing for over current protection. 9 RDT Dead time programming pin for the primary side switches and secondary side SR switches. 10 SR1DS SR1 Draintosource voltage detection. 11 SROUT2 Gate drive output for the secondary side SR MOSFET 2. 12 SROUT1 Gate drive output for the secondary side SR MOSFET 1. 13 PROUT2 Gate drive output 2 for the primary side switch. 14 PROUT1 Gate drive output 1 for the primary side switch. 15 VDD IC Supply voltage. 16 GND Ground. www.onsemi.com 2