UCC28720EVM-212

Sample & Buy Product Folder Support & Community Tools & Software Technical Documents UCC28720 SLUSBE8B – MAY 2013 – REVISED SEPTEMBER 2015 UCC28720 Constant-Voltage, Constant-Current Controller With Primary-Side Regulation 1 Features 3 Description • • The UCC28720 flyback power supply controller provides isolated-output Constant-Voltage (CV) and Constant-Current (CC) output regulation without the use of an optical coupler. The devices process information from the primary power switch and an auxiliary flyback winding for precise control of output voltage and current. 1 • • • • • • • • • < 10-mW No-Load Power Primary-Side Regulation (PSR) Eliminates OptoCoupler ±5% Voltage and Current Regulation Across Line and Load 700-V Start-Up Switch 80-kHz Maximum Switching Frequency Enables High-Power Density Charger Designs Quasi-Resonant Valley-Switching Operation for Highest Overall Efficiency Wide VDD Range Allows Small Bias Capacitor Dynamic BJT Drive Overvoltage, Low-Line, and Overcurrent Protection Functions Programmable Cable Compensation SOIC-7 Package An internal 700-V start-up switch, dynamicallycontrolled operating states and a tailored modulation profile support ultra-low standby power without sacrificing start-up time or output transient response. Control algorithms in the UCC28720 allow operating efficiencies to meet or exceed applicable standards. The output drive interfaces to a bipolar transistor power switch. Discontinuous conduction mode (DCM) with valley switching reduces switching losses. Modulation of switching frequency and primary current peak amplitude (FM and AM) keeps the conversion efficiency high across the entire load and line ranges. 2 Applications • • • The controller has a maximum switching frequency of 80 kHz and always maintains control of the peakprimary current in the transformer. Protection features help keep primary and secondary component stresses in check. The UCC28720 allows compensation for voltage drop in the cable to be programmed with an external resistor. USB-Compliant Adapters and Chargers for Consumer Electronics – Smart phones – Tablet computers – Cameras Standby Supply for TV and Desktop White Goods Device Information(1) PART NUMBER UCC28720 PACKAGE SOIC (7) BODY SIZE (NOM) 3.91 mm × 4.90 mm (1) For all available packages, see the orderable addendum at the end of the data sheet. Typical Application VOUT + VAC – UCC28720 VAUX VDD HV DRV VS CBC CS GND UDG-13090 1 An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications, intellectual property matters and other important disclaimers. PRODUCTION DATA. UCC28720 SLUSBE8B – MAY 2013 – REVISED SEPTEMBER 2015 www.ti.com Table of Contents 1 2 3 4 5 6 7 Features .................................................................. Applications ........................................................... Description ............................................................. Revision History..................................................... Pin Configuration and Functions ......................... Specifications......................................................... 1 1 1 2 3 3 6.1 6.2 6.3 6.4 6.5 6.6 6.7 3 4 4 4 4 5 6 Absolute Maximum Ratings ..................................... ESD Ratings.............................................................. Recommended Operating Conditions....................... Thermal Information .................................................. Electrical Characteristics........................................... Switching Characteristics .......................................... Typical Characteristics .............................................. Detailed Description .............................................. 8 7.1 Overview ................................................................... 8 7.2 Functional Block Diagram ......................................... 8 7.3 Feature Description................................................... 9 7.4 Device Functional Modes........................................ 11 8 Application and Implementation ........................ 16 8.1 Application Information............................................ 16 8.2 Typical Application ................................................. 16 9 Power Supply Recommendations...................... 21 10 Layout................................................................... 22 10.1 Layout Guidelines ................................................. 22 10.2 Layout Example .................................................... 22 11 Device and Documentation Support ................. 24 11.1 11.2 11.3 11.4 11.5 11.6 Device Support .................................................... Documentation Support ........................................ Community Resources.......................................... Trademarks ........................................................... Electrostatic Discharge Caution ............................ Glossary ................................................................ 24 25 26 26 26 26 12 Mechanical, Packaging, and Orderable Information ........................................................... 27 4 Revision History NOTE: Page numbers for previous revisions may differ from page numbers in the current version. Changes from Revision A (January 2014) to Revision B • Added ESD Ratings table, Feature Description section, Device Functional Modes, Application and Implementation section, Power Supply Recommendations section, Layout section, Device and Documentation Support section, and Mechanical, Packaging, and Orderable Information section. ................................................................................................ 1 Changes from Original (May 2014) to Revision A • 2 Page Page Changed CDD equation. ........................................................................................................................................................ 20 Submit Documentation Feedback Copyright © 2013–2015, Texas Instruments Incorporated Product Folder Links: UCC28720 UCC28720 www.ti.com SLUSBE8B – MAY 2013 – REVISED SEPTEMBER 2015 5 Pin Configuration and Functions D PACKAGE 7-PIN SOIC Top View 7 HV 3 6 DRV 4 5 CS VDD 1 VS 2 CBC GND Pin Functions PIN NAME NO. I/O DESCRIPTION VDD 1 I VDD is the bias supply input pin to the controller. A carefully-placed bypass capacitor to GND is required on this pin. VS 2 I Voltage sense is an input used to provide voltage and timing feedback to the controller. This pin is connected to a voltage divider between an auxiliary winding and GND. The value of the upper resistor of this divider is used to program the AC-mains run and stop thresholds and line compensation at the CS pin. CBC 3 I Cable compensation is a programming pin for compensation of cable voltage drop. Cable compensation is programmed with a resistor to GND. GND 4 — CS 5 I Current sense input connects to a ground-referenced current-sense resistor in series with the power switch. The resulting voltage is used to monitor and control the peak primary current. A series resistor can be added to this pin to compensate the peak switch current levels as the AC-mains input varies. DRV 6 O Drive is an output used to drive the base of an external high voltage NPN transistor. HV 7 I The high-voltage pin connects directly to the rectified bulk voltage and provides charge to the VDD capacitor for start-up of the power supply. The ground pin is both the reference pin for the controller and the low-side return for the drive output. Special care must be taken to return all AC decoupling capacitors as close as possible to this pin and avoid any common trace length with analog signal return paths. 6 Specifications 6.1 Absolute Maximum Ratings (1) MAX UNIT VHV Start-up pin voltage, HV MIN 700 V VVDD Bias supply voltage, VDD 38 V IDRV Continuous base current sink 50 mA IDRV Continuous base current source Self- limiting mA IVS Peak current, VS VDRV Base drive voltage at DRV VS CS, CBC Voltage TJ Operating junction temperature −1.2 mA −0.5 Self- limiting V −0.75 7 V −0.5 5 V −55 150 °C 260 °C 150 °C Lead temperature 0.6 mm from case for 10 seconds TSTG (1) −65 Storage temperature Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. Exposure to absolutemaximum-rated conditions for extended periods may affect device reliability. These are stress ratings only and functional operation of the device at these or any other conditions beyond those indicated under “Recommended Operating Conditions” is not implied. Extended exposure to stresses above the Recommended Operating Conditions may affect device reliability. All voltages are with respect to GND. Currents are positive into, negative out of the specified terminal. These ratings apply over the operating ambient temperature ranges unless otherwise noted. Submit Documentation Feedback Copyright © 2013–2015, Texas Instruments Incorporated Product Folder Links: UCC28720 3 UCC28720 SLUSBE8B – MAY 2013 – REVISED SEPTEMBER 2015 www.ti.com 6.2 ESD Ratings V(ESD) (1) (2) Electrostatic discharge VALUE UNIT Human-body model (HBM), per ANSI/ESDA/JEDEC JS-001 (1) ±2000 V Charged-device model (CDM), per JEDEC specification JESD22C101 (2) ±500 V JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process. JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process. 6.3 Recommended Operating Conditions over operating free-air temperature range (unless otherwise noted) MIN NOM MAX UNIT VDD Bias supply operating voltage 9 35 V CVDD VDD bypass capacitor 1.0 10 µF RCBC Cable-compensation resistance 10 IVS VS pin current TJ Operating junction temperature kΩ −1 mA −40 125 °C 6.4 Thermal Information UCC28720 THERMAL METRIC (1) D (SOIC) UNIT 7 PIN RθJA Junction-to-ambient thermal resistance 141.5 °C/W RθJC(top) Junction-to-case (top) thermal resistance 73.8 °C/W RθJB Junction-to-board thermal resistance 89.0 °C/W ψJT Junction-to-top characterization parameter 23.5 °C/W ψJB Junction-to-board characterization parameter 88.2 °C/W (1) For more information about traditional and new thermal metrics, see the IC Package Thermal Metrics application report, SPRA953. 6.5 Electrical Characteristics over operating free-air temperature range, VVDD = 25 V, HV = open, RCBC = open, TA = –40°C to 125°C, TA = TJ (unless otherwise noted) PARAMETER TEST CONDITIONS MIN 100 TYP MAX UNIT HIGH-VOLTAGE START UP IHV Start-up current out of VDD VHV = 100 V, VVDD = 0 V, start state 225 500 µA IHVLKG Leakage current at HV VHV = 400 V, run state, TJ = 25 ºC 0.01 0.25 µA BIAS SUPPLY INPUT IRUN Supply current, run IDRV = 0, run state 2.00 2.65 mA IWAIT Supply current, wait IDRV = 0, wait state 95 150 µA ISTART Supply current, start IDRV = 0, VVDD = 18 V, start state, IHV = 0 18 30 µA IFAULT Supply current, fault IDRV = 0, fault state 95 150 µA UNDERVOLTAGE LOCKOUT VVDD(on) VDD turn-on threshold VVDD low to high 19 21 23 V VVDD(off) VDD turn-off threshold VVDD high to low 7.35 7.7 8.15 V VVSR Regulating level Measured at no-load condition, TJ = 25°C (1) 4.01 4.05 4.09 VVSNC Negative clamp level IVS = -300 µA, volts below ground 190 250 325 mV IVSB Input bias current VVS = 4 V -0.25 0 0.25 µA VS INPUT (1) 4 V V The regulating level and over voltage at VS decreases with temperature by 0.8 mV/˚C. This compensation is included to reduce the power supply output voltage variance over temperature. Submit Documentation Feedback Copyright © 2013–2015, Texas Instruments Incorporated Product Folder Links: UCC28720 UCC28720 www.ti.com SLUSBE8B – MAY 2013 – REVISED SEPTEMBER 2015 Electrical Characteristics (continued) over operating free-air temperature range, VVDD = 25 V, HV = open, RCBC = open, TA = –40°C to 125°C, TA = TJ (unless otherwise noted) PARAMETER TEST CONDITIONS MIN TYP MAX UNIT mV CS INPUT VCST(max) Max CS threshold voltage VVS = 3.7 V 735 780 815 VCST(min) Min CS threshold voltage VVS = 4.35 V 175 190 215 mV KAM AM control ratio VCST(max) / VCST(min) 3.6 4.0 4.4 V/V VCCR Constant current regulating level CC regulation constant 317 330 344 mV KLC Line compensation current ratio IVSLS = -300 µA, IVSLS / current out of CS pin 24.0 25.0 28.6 A/A TCSLEB Leading-edge blanking time DRV output duration, V CS = 1 V 230 290 355 ns IDRS(max) Maximum DRV source current VDRV = 2 V, VVDD = 9 V, VVS = 3.85 V 32 37 41 mA IDRS(min) Minimum DRV source current VDRV = 2 V, VVDD = 9 V, VVS = 4.30 V 16 19 22 mA RDRVLS DRV low-side drive resistance IDRV = 10 mA 1 2.4 Ω VDRCL DRV clamp voltage VVDD = 35 V RDRVSS DRV pull-down in start state VOVP Over-voltage threshold At VS input, TJ = 25°C (1) VOCP Over-current threshold IVSL(run) DRIVER 5.9 7 V 20 25 kΩ 4.51 4.60 4.73 At CS input 1.4 1.5 1.6 V VS line-sense run current Current out of VS pin increasing 190 225 275 µA IVSL(stop) VS line-sense stop current Current out of VS pin decreasing 70 80 100 µA KVSL VS line sense ratio IVSL(run) / IVSL(stop) 2.45 2.80 3.05 A/A TJ(stop) Thermal shut-down temperature Internal junction temperature V V 165 °C CABLE COMPENSATION VCBC(max) Cable compensation maximum voltage Voltage at CBC at full load 2.9 3.1 3.5 V VCVS(min) Minimum compensation at VS VCBC = open, change in VS regulating level at full load -55 -15 25 mV VCBC = 0 V, change in VS regulating level at full load 275 320 380 mV VCVS(max) Maximum compensation at VS 6.6 Switching Characteristics over operating free-air temperature range (unless otherwise noted) MIN TYP MAX UNIT fSW(max) + Maximum switching frequency PARAMETER VVS = 3.7 V TEST CONDITIONS 74 80 87 kHz fSW(min) Minimum switching frequency VVS = 4.35 V 580 650 740 Hz tZTO Zero-crossing timeout delay 2.5 3.1 3.6 µs Submit Documentation Feedback Copyright © 2013–2015, Texas Instruments Incorporated Product Folder Links: UCC28720 5 UCC28720 SLUSBE8B – MAY 2013 – REVISED SEPTEMBER 2015 www.ti.com 6.7 Typical Characteristics VDD = 25 V, unless otherwise noted. 10 VDD Off IRUN, VDD = 25 V 1 Operating Current (mA) Bias Supply Current (mA) 10 Run State 0.1 0.01 VDD On 0.001 Startup State 10 20 30 0.01 -50 40 Input Voltage (V) -25 0 25 50 75 100 Temperature (°C) C001 125 C002 Figure 2. Operating Current vs. Junction Temperature Figure 1. Bias Supply Current vs. VDD Voltage 250 VS Pin Current Threshold (µA) 4.2 VS Regulating Voltage (V) ISTART, VDD = 18 V 0.001 0 4.15 4.1 4.05 4 3.95 -50 -25 0 25 50 75 100 150 100 0 -50 VVS = 3.7 V 600 500 400 VVS = 4.35 V 200 100 0 -25 0 25 50 75 Junction Temperature (°C) 100 25 50 75 100 Junction Temperature (°C) Constant Current Regulating Level (mV) 800 -50 0 125 C004 Figure 4. VS Pin Start and Stop Thresholds vs. Junction Temperature 900 300 -25 C003 Figure 3. VS Pin Regulation Voltage vs. Junction Temperature 700 Stop 50 125 Junction Temperature (°C) Start 200 3.9 Minimum Current Sense Threshold (mV) IWAIT, VDD = 25 V 0.1 0.0001 0.00001 125 340 335 330 325 320 -50 -25 0 25 50 75 Junction Temperature (°C) C005 Figure 5. Current Sense Threshold vs. Temperature 6 1 100 125 C006 Figure 6. Constant Current Regulation Level vs. Junction Temperature Submit Documentation Feedback Copyright © 2013–2015, Texas Instruments Incorporated Product Folder Links: UCC28720 UCC28720 www.ti.com SLUSBE8B – MAY 2013 – REVISED SEPTEMBER 2015 Typical Characteristics (continued) VDD = 25 V, unless otherwise noted. 85 Maximum Switching Frequency (kHz) Minimum Switching Frequency (Hz) 700 690 680 670 660 650 640 630 620 610 600 -25 0 25 50 75 100 Junction Temperature (°C) 82 81 80 79 78 77 76 125 -50 -25 0 25 50 75 100 Junction Temperature (°C) C007 125 C012 Figure 7. Minimum Switching Frequency vs. Junction Temperature Figure 8. Maximum Switching Frequency vs. Junction Temperature 40 1.6 35 Driver Low-6LGH5HVLVWDQFH  Driver Source Current (mA) 83 75 -50 VVS = 3.7 V 30 25 20 VVS = 4.35 V 15 10 1.5 1.4 1.3 1.2 1.1 1 0.9 0.8 0.7 0.6 -50 -25 0 25 50 75 100 Junction Temperature (°C) 125 -50 -25 0 25 50 75 100 Junction Temperature (°C) C008 Figure 9. Driver Output Source Current vs. Junction Temperature 125 C009 Figure 10. Driver Pull Down Resistance vs. Junction Temperature 227 High Voltage Charging Current (µA) 4.68 Overvoltage Protection Threshold (V) 84 4.66 4.64 4.62 4.6 4.58 4.56 4.54 226 225 224 223 222 221 220 219 -50 -25 0 25 50 75 Junction Temperature (°C) 100 125 -50 Figure 11. Over Voltage Protection Threshold vs. Junction Temperature -25 0 25 50 75 100 Junction Temperature (°C) C010 125 C011 Figure 12. HV Charging Current vs. Junction Temperature Submit Documentation Feedback Copyright © 2013–2015, Texas Instruments Incorporated Product Folder Links: UCC28720 7 UCC28720 SLUSBE8B – MAY 2013 – REVISED SEPTEMBER 2015 www.ti.com 7 Detailed Description 7.1 Overview The UCC28720 is a flyback power supply controller which provides accurate voltage and constant current regulation with primary-side feedback, eliminating the need for opto-coupler feedback circuits. The controller operates in discontinuous conduction mode with valley-switching to minimize switching losses. The modulation scheme is a combination of frequency and primary peak current modulation to provide high conversion efficiency across the load range. The control law provides a wide-dynamic operating range of output power which allows the power designer to achieve the