IRS27951SPBF

IRS27951S IRS27952(4)S RESONANT HALF-BRIDGE CONVERTER CONTROL IC Features             Simple primary-side control solution for fixed and variable frequency DC-DC resonant converters. Max 500kHz per channel output with 50% duty cycle Floating channel bootstrap operation up to +600Vdc Programmable minimum and maximum switching frequency Programmable soft start frequency and soft start time Programmable dead time Micropower start-up & ultra low quiescent current Over-current protection using low side MOSFET Rds(on) User initiated micropower “Sleep mode” Under-voltage Lockout Simple design with minimal component count. Lead-free Product Summary Topology Half-Bridge VOFFSET 600 V VOUT VCC IO+ & IO- (typical) 300 mA & 900 mA Dead-time (programmable) 200ns~2us Package Options Typical Application    LCD & PDP TV Telecom SMPS, PC SMPS Home Audio Systems 14-lead SOIC IRS279524S IRS27951S/IRS27952S Ordering Information Standard Pack Base Part Number IRS27951 IRS27952 IRS279524 1 www.irf.com Package Type SOIC8N SOIC8N SOIC14N Complete Part Number Form Quantity Tube/Bulk 95 IRS27951SPBF Tape and Reel 2500 IRS27951STRPBF Tube/Bulk 95 IRS27952SPBF Tape and Reel 2500 IRS27952STRPBF Tube/Bulk 55 IRS279524SPBF Tape and Reel 2500 IRS279524STRPBF © 2015 International Rectifier Submit Datasheet Feedback August 27, 2015 IRS27951S IRS27952(4)S Typical Application Diagram DC BUS VIN R1 R2 Rcc D3 Dbs 1 CDC 2 3 4 Dss Rss RT Cbs U1 VCC VB RT HO CT/SD VS COM LO 8 M1 Rg1 D1 7 6 5 Lr IRS2795 M2 Rg2 Rmax CT Css LOAD COUT D2 Cr RTN Rled Rbias Rs1 Cf1 U2 Cf2 Rf2 U3 TL431 Rs2 2 www.irf.com © 2015 International Rectifier Submit Datasheet Feedback August 27, 2015 IRS27951S IRS27952(4)S Table of Contents Page Ordering Information 1 Typical Application Diagram 2 Absolute Maximum Ratings 5 Recommended Operating Conditions 5 Electrical Characteristics 6 Functional Block Diagram 8 Input/Output Pin Equivalent Circuit Diagram 9 Lead Definitions 10 Lead Assignments 10 State Diagram 12 Application Information and Additional Details 13 Package Details 23 Tape and Reel Details 25 Part Marking Information 27 Qualification Information 28 3 www.irf.com © 2015 International Rectifier Submit Datasheet Feedback August 27, 2015 IRS27951S IRS27952(4)S Description The IRS2795(1,2)(4) is a self oscillating half-bridge driver IC for DC-DC resonant converter applications, especially the LLC resonant half-bridge converter. The frequency and dead time can be programmed externally using two external components. The IC offers over current protection using the on state resistance of the low-side MOSFET. The IC can be disabled by externally pulling the voltage at the CT/SD pin below its enable voltage threshold 4 www.irf.com © 2015 International Rectifier Submit Datasheet Feedback August 27, 2015 IRS27951S IRS27952(4)S Absolute Maximum Ratings Absolute maximum ratings indicate sustained limits beyond which damage to the device may occur. All voltage parameters are absolute voltages referenced to COM, all currents are defined positive into any lead. The thermal resistance and power dissipation ratings are measured under board mounted and still air conditions. Symbol VCC VB VS VHO VLO VCT VRT IRT dVs/dt TJ TS PD RthJA Definition Supply Voltage High-side Floating Supply Voltage High-side Floating Supply Offset Voltage High-side Floating Output Voltage Low-side Output Voltage CT/SD Pin Voltage RT Pin Voltage RT pin source current Allowable offset voltage slew rate Operating Junction Temperature Storage Temperature Package power dissipation @ TA ≤ 25°C Thermal resistance, junction to ambient (8 lead SOIC) (14 lead SOIC) (8 lead SOIC) (14 lead SOIC) Min. Max. -0.3 -0.3 VB – 25 VS – 0.3 -0.3 -0.3 -0.3 ---50 -40 -55 — — — — 25 625 VB + 0.3 VB + 0.3 VCC + 0.3 VCC + 0.3 VCC + 0.3 2 50 150 150 0.833 1.04 150 120 Units V mA V/ns °C W °C/W Recommended Operating Conditions For proper operation the device should be used within the recommended conditions. Symbol Definition Min. Max. Units VBS High-side floating supply voltage 10 Vcc † VS Steady-state high-side floating supply offset voltage 600 V -3.0 VCC Supply voltage 12 18 fsw Switching Frequency --500 kHz † Care should be taken to avoid output switching conditions where the V S node flies inductively below ground by more than 5 V. Recommended Component Values Symbol RRT CCT 5 Component RT pin resistor value CT pin capacitor value www.irf.com © 2015 International Rectifier Min. 2 200 Submit Datasheet Feedback Max. 100 2000 Units k pF August 27, 2015 IRS27951S IRS27952(4)S Electrical Characteristics VCC=VBS=15V, VS=0V, CVCC=CBS=0.1uF, CLO=CHO=1nF, RT=50.5k, CT=200pF and TA = 25°C unless otherwise specified. The output voltage and current (VO and IO) parameters are referenced to COM and are applicable to the respective HO and LO output leads. Symbol Definition Low Voltage Supply Characteristics Min Typ Max Units Test Conditions V N/A µA VCC = VCCUV+ -0.1V VCCUV+ VCC turn on threshold 10.1 11 11.9 VCCUV- VCC turn off threshold (Under Voltage Lock Out) 8.1 9 9.9 VCCUVHYS VCC undervoltage lockout hysteresis --- 2 --- ICCSTART VCC startup current --- 50 100 Sleep mode VCC supply current --- 150 200 VCT/SD VCCUV+ SLEEP CURRENT FAULT Oscillator and Gates Inactive ICT = ICTSTART ICC=ISLEEP Oscillator and Gates Inactive Internally discharge RT and CT pins VCT < VEN2 VCT > VEN1 NORMAL VS > VOCP @ LO=High Oscillator and Gates Active ICTCHARGE=IRT Over Current Protection Active UVLO Mode The IC remains in the UVLO condition until the voltage on the VCC pin exceeds the VCC turn on threshold voltage, VCCUV+. During the time the IC remains in the UVLO state, the gate drive circuit is inactive and the IC draws a quiescent current of ICC START. The UVLO mode is accessible from any other state of operation whenever the IC supply voltage condition of VCC < VCC UV- occurs. Sleep Mode When VCC exceeds the VCCUV+ threshold the IRS2795(1,2)(4) starts to charge up CT capacitor with ICT startup current towards the enable threshold, VEN1. During this period, the IC is in Sleep mode. The oscillator and gate drive circuits are disabled and the Ic consumes ISLEEP. When the voltage at the CT/SD pin exceeds VEN1, the IC is pulled out of sleep mode and the 2V reference voltage at the RT pin is enabled. The IC can be placed in Sleep mode while operating in Normal mode by externally pulling the CT/SD pin below VEN2. When this occurs, the RT pin of the IC is internally discharged to COM to ensure a system restart with softstart. Normal Mode The IC enters in normal operating mode once the UVLO voltage and VEN1 has been exceeded. The RT pin voltage is 2V under normal mode. Gate drive signal appears at HO and LO with fixed 50% duty-cycle. During this mode, the over-current protection scheme using the VS sense circuitry is active. Current Fault Mode When operating in Normal mode, the IC senses the voltage on the VS pin each time the low-side device is turned ON (with a leading edge blanking on LO, tblank). When the voltage sensed exceeds VOCP, the IC terminates the current gate pulse, disables the oscillator and gate drivers, and enters the Current Fault mode. When the IC enters this state, RT and CT/SD pins are internally discharged and IC supply voltage must be recycled before the IC can restart with soft-start again 12 www.irf.com © 2015 International Rectifier Submit Datasheet Feedback August 27, 2015 IRS27951S IRS27952(4)S Application Information and Additional Details Information regarding the following topics is included as subsections within this section of the datasheet.          General Description IC Supply Circuit & Low start-up current Multi-function 2 Pin Oscillator Frequency and Dead-time Calculation User initiated Micropower Sleep mode Gate Drive Capability System Protection Features PCB Layout Tips Additional Documentation General Description The IRS2795(1,2)(4) is a double-ended controller for the resonant half-bridge topology. It provides complementary outputs with 50% (max) duty cycle; the high-side and low-side bridge devices are driven 180° out-of-phase for exactly the same time. A programmable dead-time inserted between the turn-OFF of one switch and the turn-ON of the other one guarantees soft-switching operation. The IC incorporates a multi-function oscillator that allows the designer to program all the necessary features to control a half bridge resonant switch-mode power supply featuring low standby power. The IC also incorporates additional protection features for robust operation and provides a high performance solution while minimizing external components, design time, and printed circuit board real estate. The IC enables the designer to externally program all the following features using a 2 pin RC oscillator – operating frequency range (start-up, minimum and maximum frequency), dead time, soft-start time and sleep mode operation. IRS2795(1,2)(4) also uses IR’s proprietary high-voltage technology to implement a VS sensing circuitry that monitors the current through the low-side half bridge MOSFET for short circuit faults. By using the R DSON of the lowside MOSFET, the IRS2795(1,2)(4) eliminates the need for an additional current sensing resistor, filter and currentsensing pin. This protection feature is latched and the thresholds are fixed at 2V for IRS27951 and 3V for IRS27952(4). Finally, the controller IC also features a micro power startup current (ICC