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1、8GD1 5GD2 7VCC 6GND 3 2 1 4 OC RT DT SS UCC25600 + VS UCC25600 SLUS846B SEPTEMBER 2008REVISED JULY 2011 8-Pin High-Performance Resonant Mode Controller Check for Samples: UCC25600 1FEATURES DESCRIPTION Variable Switching Frequency Control The UCC25600 high performance resonant mode Programmable Mini
2、mum Switching Frequency controllerisdesignedfordc-to-dcapplications With 4% Accuracy (3% accuracy at utilizing resonant topologies, especially the LLC half temperature range: -20C to 105C) bridge resonant converter. This highly integrated Programmable Maximum Switching Frequency controller implement
3、s frequency modulation control Programmable Dead Time for Best Efficiency and complete system functions in only an 8-pin Programmable Soft-Start Timepackage. Switching to the UCC25600 will greatly simplify the system design, layout and improve time Easy ON/OFF Control to market, all at a price point
4、 lower than competitive Over-Current Protection 16-pin device offerings. Over-Temperature Protection Theinternaloscillatorsupportstheswitching Bias Voltage UVLO and OVP frequencies from 40 kHz to 350 kHz. This high Integrated Gate Driver With 0.4-A Source and accuracy oscillator realizes the minimum
5、 switching 0.8-A Sink Capability frequency limiting with 4% tolerance, allowing the Operating Temperature Range: 40C to 125C designer to avoid over design of the power stage SOIC 8-Pin Packageand, thus, further reducing overall system cost. The programmabledeadtimeenableszero-voltage switching with
6、minimum magnetizing current. This will APPLICATIONS maximizesystemefficiencyacrossavarietyof 100-W to 1-kW Power Supplies applications.Theprogrammablesoft-starttimer LCD, Plasma and DLP TVs maximizes design flexibility demanded by the varied Adaptors, Computing and ATX Power Suppliesrequirements of
7、end equipments utilizing a half bridge topology. By incorporating 0.4-A source and 0.8-A Home Audio Systems sink driving capability, a low cost, reliable gate driver Electronic Lighting Ballasts transformer is a real option. The UCC25600 delivers complete system protection functions including over c
8、urrent, UVLO, bias supply OVP and over temperature protection. TYPICAL APPLICATION DIAGRAM 1 Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of
9、 this data sheet. PRODUCTION DATA information is current as of publication date. Copyright 20082011, Texas Instruments Incorporated Products conform to specifications per the terms of the Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameter
10、s. UCC25600 SLUS846B SEPTEMBER 2008REVISED JULY ORDERING INFORMATION PART NUMBERPACKAGEOPERATING TEMPERATURE UCC25600D8-Pin SOIC-40C to 125C ABSOLUTE MAXIMUM RATINGS(1) (2) (3) (4) over operating free-air temperature range (unless otherwise noted) PARAMETERLIMITUNIT Supply voltage, VCC22 V Voltage,
11、GD1, GD2-0.5 to VCC + 0.5 Gate drive current continuous, GD1, GD2+/- 25 Current, RT-5mA Current, DT-0.7 Operating junction temperature, TJ40 to 125 Storage temperature, TSTG65 to 150C Lead temperature (10 seconds)260 (1)These are stress limits. Stress beyond these limits may cause permanent damage t
12、o the device. Functional operation of the device at these or any conditions beyond those indicated under RECOMMENDED OPERATING CONDITIONS is not implied. Exposure to absolute maximum rated conditions for extended periods of time may affect device reliability. (2)All voltages are with respect to GND.
13、 (3)All currents are positive into the terminal, negative out of the terminal. (4)In normal use, terminals GD1 and GD2 are connected to an external gate driver and are internally limited in output current. ELECTROSTATIC DISCHARGE (ESD) PROTECTION PARAMETERRATINGUNIT Human Body Model (HBM)2,000 V Cha
14、rged Device Model (CDM)500 DISSIPATION RATINGS THERMAL IMPEDANCE, PACKAGETA= 25C POWER RATINGTA= 85C POWER RATING JUNCTION-TO-AMBIENT 8-Pin SOIC150C/watt (1) (2) 667 mW (1) 267 mW (1) (1)Thermal resistance is a strong function of board construction and layout. Air flow will reduce thermal resistance
15、. This number is only a general guide. (2)Thermal resistance calculated with a low-K methodology. RECOMMENDED OPERATING CONDITIONS over operating free-air temperature range (unless otherwise noted) PARAMETERMINIMUMMAXIMUMUNIT VCC input voltage from a low-impedance source11.518.0V RT resistance18.666
16、 k DT resistance3.339 SS capacitor0.011F 2Copyright 20082011, Texas Instruments Incorporated UCC25600 SLUS846B SEPTEMBER 2008REVISED JULY 2011 ELECTRICAL CHARACTERISTICS over operating free-air temperature range, 40C TA 125C, TJ= TA, VCC = 12 V, GND = 0 V, RRT= 4.7 k, RDT= 16.9 k, CVCC= 1 F, (unless
17、 otherwise noted) SYMBOLPARAMETERTEST CONDITIONSMINTYPMAXUNITS Bias Supply (VCC) VCC current, disabledSS = 0 V11.5 mA VCC current, enabledSS = 5 V, CGD1= CGD2= 1 nF2.557.5 VCC current, UVLOVCC = 9 V100400A UVLO turn-on thresholdMeasured at VCC rising9.910.511.1 VUVLOUVLO turn-off thresholdMeasured a
18、t VCC falling8.99.510.1 UVLO hysteresisMeasured at VCC0.7 11.3 V OVP turn-off thresholdMeasured at VCC rising182022 VOVPOVP turn-on thresholdMeasured at VCC falling161820 OVP hysteresisMeasured at VCC1.522.5 Dead Time (DT) TDTDead timeRDT= 16.9 k390420450ns Oscillator -40C to 125C40.0441.7043.36 Min
19、imum switching frequency at FSW(min)kHz GD1, GD2 -20C to 105C40.4541.7042.95 KICOSwitching frequency gain/I (RT)RRT= 4.7 k, IRT= 0 to 1 mA6080100Hz/A GD1, GD2 on time mismatching-5050ns Switching frequency starting burst FSW_BMSS = 5 V300350400 mode Switching frequency to come out of SS = 5 V2803303
20、80 kHz burst mode -40C to 125C122142.5162 FSW(start)Switching frequency at soft start -20C to 105C125142.5160 External Disable/Soft Start Enable thresholdMeasure at SS rising1.11.21.3 Disable thresholdMeasured at SS falling0.8511.1V Disable hysteresisMeasured at SS0.150.35 Measured between SS (falli
21、ng) and Disable prop. delay250500750ns GD2 (falling) Source current on ISS pinVSS= 0.5 V-225-175-125 ISSA Source current on ISS pinVSS= 1.35 V-5.5-5-4.5 Copyright 20082011, Texas Instruments Incorporated3 UCC25600 SLUS846B SEPTEMBER 2008REVISED JULY ELECTRICAL CHARACTERISTICS (continued) over operat
22、ing free-air temperature range, 40C TA 125C, TJ= TA, VCC = 12 V, GND = 0 V, RRT= 4.7 k, RDT= 16.9 k, CVCC= 1 F, (unless otherwise noted) SYMBOLPARAMETERTEST CONDITIONSMINTYPMAXUNITS Peak Current Limit Level 1 over current threshold VOC VOC1(off)0.911.1 rising Level 2 over current latch VOC2(off)1.82
23、.02.2V threshold VOCrising Level 1 over current threshold VOC VOC1(on)0.50.60.7 falling Td_OCPropagation delay60200500ns IOCOC bias currentVOC= 0.8 V-200200nA Gate Drive GD1, GD2 output voltage highIGD1, IGD2= 20 mA911V GD1, GD2 on resistance highIGD1, IGD2= 20 mA1230 GD1, GD2 output voltage lowIGD1
24、, IGD2= 20 mA0.080.2V GD1, GD2 on resistance lowIGD1, IGD2= 20 mA410 Rise time GDx1 V to 9 V, CLOAD= 1 nF1835 ns Fall time GDx9 V to 1 V, CLOAD= 1 nF1225 GD1, GD2 output voltage during VCC = 6 V, IGD1, IGD2= 1.2 mA0.51.75V UVLO Thermal Shutdown Thermal shutdown threshold160 C Thermal shutdown recove
25、ry 140 threshold 4Copyright 20082011, Texas Instruments Incorporated 1 2 3 45 6 7 8GD1 VCC GND GD2 DT RT OC SS UCC25600 SLUS846B SEPTEMBER 2008REVISED JULY 2011 DEVICE INFORMATION 8-Pin SOIC, Top View TERMINAL FUNCTIONS TERMINAL DESCRIPTION NAMENO.I/O This pin sets the dead time of high-side and low
26、-side switch driving signals. Connect a resistor to ground. With internal 2.25-V voltage reference, the current flowing DT1Ithrough the resistor sets the dead time. To prevent shoot through when this pin is accidentally short to ground, the minimum dead time is set to 120 ns. Any dead time setting l
27、ess than 120 ns will automatically have 120-ns dead time. The current flowing out of this pin sets the frequency of the gate driver signals. Connect the opto-coupler collector to this pin to control the switching frequency for regulation purpose. Parallel a resistor to ground to set the minimum curr
28、ent flowing RT2Iout of the pin and set the minimum switching frequency. To set the maximum switching frequency limiting, simply series a resistor with the opto-coupler transistor. This resistor sets the maximum current flowing out of the pin and limits the maximum switching frequency. Over-current p
29、rotection pin. When the voltage on this pin is above 1 V, gate driver signals are actively pulled low. After the voltage falls below 0.6 V, the gate driver OC3I signal recovers with soft start. When OC pin voltage is above 2 V, the device is latched off. Bringing VCC below UVLO level resets the over
30、current latch off. Soft-start pin. This pin sets the soft-start time of the system. Connect a capacitor to ground. Pulling this pin below 1 V will disable the device to allow easy ON/OFF SS4I control. The soft-start function is enabled after all fault conditions, including bias supply OV, UVLO, over
31、-current protection and over-temperature protection. GD18O High-side and low-side switch gate driver. Connect gate driver transformer primary side to these two pins to drive the half bridge. GD25O GND6-Ground. Bias Supply. Connect this pin to a power supply less than 20 V. Parallel a 1-F VCC7- capac
32、itor to ground to filter out noise. Copyright 20082011, Texas Instruments Incorporated5 1 DT Thermal ShutDown + 160oC/140oC T J TSD 2 Feed back RT 7 VCC GD1 UVLO 10.5V 9.5V 8 + 6 GND 5GD2 VCC 4 6V SS 3 OC + 1V OC + 20V 18V OV Vss GD_Stop 2.25V Dead time generator 2.5V OSC + 1.2V/1V FAULT Q Q SET CLR
33、 S R Vss Ic 5uA170uA FAULT Q Q SET CLR D UVLO OV OC TSD RDT Css + 2V OC_latch UCC25600 SLUS846B SEPTEMBER 2008REVISED JULY Block Diagram 6Copyright 20082011, Texas Instruments Incorporated BIAS SUPPLY CURRENT vs BIAS SUPPLY VOLTAGE 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 67891011121314 Vvcc - Bias S
34、upply Voltage - V Ivcc - Bias Supply Current - mA OC Open SWITCHING FREQUENCY vs RT CURRENT 0 50 100 150 200 250 300 350 012345 IRT - RT Current - mA Fsw - Switching Frequency - kHz -40 C 25 C 125 C DEAD TIME vs DT CURRENT 0 100 200 300 400 500 600 700 800 900 1000 0100200300400500600700 IDT - DT Cu
35、rrent - uA DT - Dead Time - - 40 C 25 C 125 C DEAD TIME vs DT RESISTOR 0 100 200 300 400 500 600 700 800 900 1000 051015202530354045 RDT - DT Resistor - kOhm DT - Dead Time - -40 C 25 C 125 C UCC25600 SLUS846B SEPTEMBER 2008REVISED JULY 2011 TYPICAL CHARACTERISTICS At VCC= 12 V, RRT= 4.7 k, RDT= 16.
36、9 k, VSS= 5 V, VOC= 0 V; all voltages are with respect to GND, TJ= TA = 25C, unless otherwise noted. Figure 1.Figure 2. Figure 3.Figure 4. Copyright 20082011, Texas Instruments Incorporated7 GATE DRIVE RISING; VCC=15V -2 0 2 4 6 8 10 12 14 16 02004006008001000 Time - ns Gate Drive Voltage - V -0.1 0
37、 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 Gate Drive Current - A Gate Drive Voltage Gate Drive Source Current GATE DRIVE FALLING; VCC=15V -2 0 2 4 6 8 10 12 14 16 0100200300400500600 Time - ns Gate Drive Voltage - V -0.2 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 Gate Drive Current - A Gate Drive Voltage Gate Drive Sin
38、k Current OC PROPAGATION DELAY vs TEMPERATURE 0 50 100 150 200 250 300 -60-40-20020406080100 120 140 Tj - Junction Temperature - C Propagation Delay - ns UVLO THRESHOLD vs TEMPERATURE 8 9 10 11 12 -60-40-20020406080100 120 140 Tj - Junction Temperature - C UVLO Threshold - UVLO On Threshold - VCC Ri
39、sing UVLO Off Threshold -VCC Falling UCC25600 SLUS846B SEPTEMBER 2008REVISED JULY TYPICAL CHARACTERISTICS (continued) Figure 5.Figure 6. Figure 7.Figure 8. 8Copyright 20082011, Texas Instruments Incorporated VCC OVER VOLTAGE THRESHOLD vs TEMPERATURE 16 17 18 19 20 21 22 -60-40-20020406080100 120 140
40、 Tj - Junction Temperature - C VCC Over Voltage Threshold - V OVP Off Threshold - VCC Rising OVP On Threshold -VCC Falling OVER CURRENT THRESHOLD vs TEMPERATURE 0 0.5 1 1.5 2 2.5 -60-40-20020406080100 120 140 Tj - Junction Temperature - C Voc Over Current Threshold - V OC Off Threshold - Voc Rising
41、OC On Threshold - Voc Falling OC Latch Threshold - Voc Rising ON TIME MISMATCH vs SWITCHING FREQUENCY 0 20 40 60 80 100 050100150200250300350 Switching Frequency - kHz On Time Mismatch - ns UCC25600 SLUS846B SEPTEMBER 2008REVISED JULY 2011 TYPICAL CHARACTERISTICS (continued) Figure 9.Figure 10. Figu
42、re 11. Copyright 20082011, Texas Instruments Incorporated9 CrLr Lm n:1:1 CrLr LmVge Voe Re UCC25600 SLUS846B SEPTEMBER 2008REVISED JULY APPLICATION INFORMATION Principal of Operation The soft-switching capability, high efficiency and long holdup time make the LLC resonant converter attractive for ma
43、ny applications, such as digital TV, ac/dc adapters and computer power supplies. Figure 12 shows the schematic of the LLC resonant converter. Figure 12. LLC Resonant Converter The LLC resonant converter is based on the Series Resonant Converter (SRC). By utilizing the transformer magnetizing inducto
44、r, zero-voltage switching can be achieved over a wide range of input voltage and load. As a result of multiple resonances, zero-voltage switching can be maintained even when the switching frequency is higher or lower than resonant frequency. This simplifies the converter design to avoid the zero-cur
45、rent switching region, which can lead to system damage. The converter achieves the best efficiency when operated close to its resonant frequency at a nominal input voltage. As the switching frequency is lowered the voltage gain is significantly increased. This allows the converter to maintain regula
46、tion when the input voltage falls low. These features make the converter ideally suited to operate from the output of a high-voltage boost PFC pre-regulator, allowing it to hold up through brief periods of ac line-voltage dropout. Due to the nature of resonant converter, all the voltages and current
47、s on the resonant components are approximately sinusoidal. The gain characteristic of LLC resonant converter is analyzed based on the First Harmonic Approximation (FHA), which means all the voltages and currents are treated as sinusoidal shape with the frequency same as switching frequency. Accordin
48、g to the operation principle of the converter, the LLC resonant converter can be draw as the equivalent circuit as shown in Figure 13. Figure 13. LLC Resonant Converter Equivalent Circuit 10Copyright 20082011, Texas Instruments Incorporated 2 2 8 e Rn R p = 1 2 me ome me DC r mer j L R Vj LR j L R V
49、/ j L j LRj C w w w w ww + = + + 0 n f f f = 2 o DC V M V/ = m n r L L L = 0 1 2 rr f L Cp = rr e e L / C Q R = ()() 2 2 11 = +-+ + nn nnnnnne L f M L fffjf L Q UCC25600 SLUS846B SEPTEMBER 2008REVISED JULY 2011 In this equivalent circuit, the Vgeand Voeare the fundamental harmonics of the voltage generated by the half bridge and the voltage on the transformer primary side, respectively. These voltages can be calculated through Fourier analysis. The load resistor Reis the equivalent resistor of the load, and it can be calculated as: (1) Based on this equivale