TPS92010DR

TPS92010 www.ti.com SLUSA14 – DECEMBER 2009 8-PIN HIGH-EFFICIENCY, OFFLINE LED LIGHTING CONTROLLER Check for Samples: TPS92010 FEATURES . 1 • 2 • • • • • • • • LED Lighting Current Driver Controller with Energy Saving Features Quasi-Resonant Mode Operation for Reduced EMI and Low Switching Losses (Low Voltage Switching) Low Standby Current for Deep Dimming Efficiency Power Consumption Low Startup Current: 25 μA Maximum Programmable Line and Load Overvoltage Protection – Provides Open LED Protection Internal Overtemperature Protection Current Limit Protection – Cycle-by-Cycle Power Limit – Primary-Side Overcurrent Hiccup Restart Mode 1-A Sink TrueDrive™, –0.75-A Source Gate Drive Output Programmable Soft-Start . APPLICATIONS • • • Residential LED Lighting Drivers for A19 E12/E26/27, GU10, MR16, PAR30/38 Integral Lamps Drivers for Wall Sconces, Pathway Lighting and Overhead Lighting Drivers for Wall Washing, Architectural and Display Lighting DESCRIPTION The TPS92010 is a PWM controller with advanced energy features to provide high efficiency driving for LED lighting applications. The TPS92010 incorporates frequency fold back and low power mode operation to reduce the operation frequency at light load and no load operations. The TPS92010 is offered in the 8-pin SOIC (D) package. Operating junction temperature range is –40°C to 105°C. Primary Secondary TPS92010 Feedback 1 SS VSD 7 2 FB LPM 8 3 PCS VDD 6 4 GND GD 5 + TL431 UDG-09220 1 2 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 this data sheet. TrueDrive is a trademark of Texas Instruments. PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of the Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. Copyright © 2009, Texas Instruments Incorporated TPS92010 SLUSA14 – DECEMBER 2009 www.ti.com This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled with appropriate precautions. Failure to observe proper handling and installation procedures can cause damage. ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may be more susceptible to damage because very small parametric changes could cause the device not to meet its published specifications. ABSOLUTE MAXIMUM RATINGS over operating free-air temperature range unless otherwise noted (1) TPS92010 UNIT 27 V Supply current 20 mA Output sink current (peak) 1.2 Output source current (peak) –0.8 VDD Supply voltage range IDD IGD(sink) IGD(source) Analog inputs IDD < 20 mA FB, PCS, SS VVSD A –0.3 to 6.0 IVSD(source) VLPM –1.0 mA 30 V 650 mW VDD = 0 V to 30 V Power dissipation SOIC-8 package, TA = 25°C TJ Operating junction temperature range –55 to 150 Tstg Storage temperature –65 to 150 TLEAD Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds (1) V –1.0 to 6.0 °C 300 Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. 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. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. All voltages are with respect to GND. Currents are positive into, negative out of the specified terminal. RECOMMENDED OPERATING CONDITIONS MIN VDD Input voltage IGD Output sink current TJ Operating junction temperature MAX V 105 °C 0 –40 UNIT 21 A ELECTROSTATIC DISCHARGE (ESD) PROTECTION MIN MAX Human body model 2000 CDM 1500 2 Submit Documentation Feedback UNIT V Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TPS92010 TPS92010 www.ti.com SLUSA14 – DECEMBER 2009 ELECTRICAL CHARACTERISTICS VDD = 15 V, 0.1-μF capacitor from VDD to GND, 3.3-nF capacitor from SS to GND charged over 3.5 V, 500-Ω resistor from VSD to -0.1 V, FB = 4.8 V, LPM = not connected, 1-nF capacitor from GD to GND, PCS = GND, TA = –40°C to 105°C, (unless otherwise noted) PARAMETER TEST CONDITIONS MIN TYP MAX UNIT OVERALL ISTARTUP Startup current VDD = VUVLO –0.3 V 12 25 ILPM Standby current VFB = 0 V 350 550 IDD Operating current Not switching 2.5 3.5 130 kHz, QR mode 5.0 7.0 21 26 27 10.3 13.0 15.3 VDD clamp FB = GND, IDD = 10 mA μA mA V UNDERVOLTAGE LOCKOUT VDD(uvlo) ΔVDD(uvlo) Startup threshold Stop threshold 6.3 8 9.3 Hysteresis 4.0 5.0 6.0 V PWM (Ramp) (1) DMIN Minimum duty cycle VSS = GND, VFB = 2 V DMAX Maximum duty cycle QR mode, fS = max, (open loop) 0% 99% OSCILLATOR (OSC) fQR(max) Maximum QR and DCM frequency 117 130 143 fQR(min) Minimum QR and FFM frequency VFB = 1.3 V 32 40 48 fSS Soft start frequency VSS = 2.0 V 32 40 48 dTS/dFB VCO gain TS for 1.6 V < VFB < 1.8 V –38 –30 –22 μs/V 12 20 28 kΩ 3.30 4.87 6.00 kHz FEEDBACK (FB) RFB Feedback pullup resistor VFB FB, no load QR mode Low power mode ON threshold VFB threshold 0.3 0.5 0.7 Low power mode OFF threshold VFB threshold 1.2 1.4 1.6 Low power mode hysteresis VFB threshold Burst hysteresis VFB during low power mode V 0.9 0.13 0.25 0.42 1.0 2.4 3.8 kΩ 2.0 μA LOW POWER MODE RDS(on) LPM on resistance VLPM = 1 V ILPM(leakage) LPM leakage/off current VFB = 0.44 V, VSTATUS = 15 V PEAK CURRENT SENSE (PCS) APCS(FB) VPCS(os) (1) –0.1 (1) Gain, FB = ΔVFB / ΔVPCS QR mode Shutdown threshold VFB = 2.4 V, VSS = 0 V PCS to output delay time (power limit) PCS to output delay time (over current fault) PCS discharge impedance PCS = 0.1 V, VSS = 0 V PCS offset SS mode, VSS ≤ 2.0 V, via FB 2.5 1.13 V/V 1.25 1.38 V PCS = 1.0 VPULSE 175 300 PCS = 1.45 VPULSE 100 150 25 115 250 Ω 0.35 0.40 0.45 V ns RPCST and CPCST are not connected in the circuit for maximum and minimum duty cycle tests, current sense tests and power limit tests. Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TPS92010 3 TPS92010 SLUSA14 – DECEMBER 2009 www.ti.com ELECTRICAL CHARACTERISTICS (continued) VDD = 15 V, 0.1-μF capacitor from VDD to GND, 3.3-nF capacitor from SS to GND charged over 3.5 V, 500-Ω resistor from VSD to -0.1 V, FB = 4.8 V, LPM = not connected, 1-nF capacitor from GD to GND, PCS = GND, TA = –40°C to 105°C, (unless otherwise noted) PARAMETER TEST CONDITIONS MIN TYP MAX UNIT μA POWER LIMIT (PL) (2) PCS current IVSD = -300 μA –165 –150 –135 PCS working range QR mode, peak PCS voltage 0.70 0.81 0.92 PL threshold Peak CS voltage + PCS offset 1.05 1.20 1.37 ISS(chg) Softstart charge current VSS = GND –8.3 –6.0 –4.5 μA ISS(dis) Softstart discharge current VSS = 0.5 V 2.0 5.0 10 mA VSS Switching ON threshold Output switching start 0.8 1.0 1.2 V –450 –370 μA –25 mV 4.13 V IPL(Pcs) VPL V SOFT START (SS) VALLEY SWITCHING DETECT (VSD) IVSD(line) Valley switching detect IVSD threshold, GD = HI –512 VVSD(on) VSD voltage at OUT = HIGH VFB = 4.8 V, VSS = 5.0 V, IVSD(on), = –300 μA –125 VVSD(load) Load overvoltage protection VVSD threshold, GD = LO 3.37 3.75 THERMAL PROTECTION (TSP) (3) Thermal shutdown (TSP) temperature 140 Thermal shutdown hysteresis °C 15 GATE DRIVE tRISE Rise time tFALL Fall time (2) (3) 4 10% to 90% of 13 V typical out clamp 50 75 10 20 ns RPCST and CPCST are not connected in the circuit for maximum and minimum duty cycle tests, current sense tests and power limit tests. Specified by design. Not production tested. Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TPS92010 TPS92010 www.ti.com SLUSA14 – DECEMBER 2009 OPEN LOOP TEST CIRCUIT VFB [A]R PCST 37.4 kW [A]C + PCST 560 pF TPS92010 1 SS LPM LPM 8 RVSD 500 W CSS 3.3 nF 2 FB VSD 7 3 PCS VDD 6 VVSD CFBT 47 pF VPCS IPCS VDD IVDD 4 GND GD CVDD 100 nF GND CBIAS 1 mF 5 VGD RGD 10 W CGD 1.0 nF UDG-09221 A. RPCST and CPCST are not connected for maximum and minimum duty cycle tests, current sense tests and power limit tests. Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TPS92010 5 TPS92010 SLUSA14 – DECEMBER 2009 www.ti.com BLOCK DIAGRAM VSD VDD 6 7 TPS92010 REF 13/8 V On-Chip Thermal Shutdown Fault Logic REF_OK UVLO LOAD_VSD OVR_T LPM LINE_VSD PCS SS_DIS SS_OVR LOW PWR RUN LPM 8 SS 26 V + UVLO 5.0 VREF QR DETECT ___ LOAD_VSD GD LINE_VSD PCS LOW POWER QR_DONE OSCILLATOR RUN SS_OVR QR_DONE CLK OSC_CL 1 REF D SET + Low Power Mode OSC_CL FB FB_CLAMP REF CLR PL 1.2 V GAIN = 1/2.5 FB 2 20 kW VDD Modulation Comparison Q 5 GD 3 PCS 4 GND Q + + 1.5 R R 400 mV UDG-09222 6 Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TPS92010 TPS92010 www.ti.com SLUSA14 – DECEMBER 2009 ORDERING INFORMATION (1) TA PACKAGES PART NUMBER –40°C to 105°C SOIC (D) (1) TPS92010D SOIC (D) package is available taped and reeled by adding “R” to the above part numbers. Reeled quantities for TPS92010DR is 2,500 devices per reel. DEVICE INFORMATION TPS92010 (TOP VIEW) SS 1 8 LPM FB 2 7 VSD PCS 3 6 VDD GND 4 5 GD PIN FUNCTIONS PIN NAME NO. I/O DESCRIPTION FB 2 I Feedback input or control input from the output sensing network to the PWM comparator used to control the peak current in the power MOSFET. An internal 20-kΩ resistor is between this pin and the internal 5-V regulated voltage. The voltage of this pin controls the mode of operation in one of the three modes: quasi resonant (QR), frequency foldback mode (FFM) and low power mode (LPM). GND 4 – Ground for internal circuitry. Connect a ceramic 0.1-μF bypass capacitor between VDD and GND, with the capacitor as close to these two pins as possible. GD 5 O 1-A sink (TrueDrive™ ) and 0.75-A source gate drive output. This output drives the power MOSFET and switches between GND and the lower of VDD or the 13-V internal output clamp. LPM 8 O The low power mode pin is an ACTIVE HIGH open drain signal that indicates the device has entered low power mode. LPM pin is high during UVLO, (VDD < startup threshold), and softstart, (SS < FB). PCS 3 I Peak current sense input, also programs power limit and is used to control modulation and activate overcurrent protection. The PCS voltage input originates across a current sense resistor and ground. Power limit is programmed with an effective series resistance between this pin and the current sense resistor. SS 1 I Soft-start programming pin. Program the soft-start rate with a capacitor to ground; the rate is determined by the capacitance and the internal soft-start charge current. Placement of the soft-start capacitor is critical and should be placed as close as possible to the SS pin and GND, keeping trace length to a minimum. All faults discharge the SS pin to GND through an internal MOSFET with an RDS(on) of approximately 100 Ω. The internal modulator comparator reacts to the lowest of the SS voltage, the internal FB voltage and the peak current limit. VDD 6 I Provides power to the device. Use a ceramic 0.1-μF by-pass capacitor for high-frequency filtering of the VDD pin, as described in the GND pin description. Operating energy is usually delivered from auxiliary winding. To prevent hiccup operation during start-up, a larger energy storage cap is also needed between VDD and GND. VSD 7 I The valley switching detect (VSD) pin senses line, load and resonant conditions using the primary bias winding. Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TPS92010 7 TPS92010 SLUSA14 – DECEMBER 2009 www.ti.com APPLICATION INFORMATION FUNCTIONAL DESCRIPTION The TPS92010 is a multi-mode LED Lighting controller, as illustrated in Figure 1 and Figure 2. The mode of operation depends upon input and dimming conditions. Under all modes of operation, the TPS92010 terminates the GD = HI signal based on the switch current. Thus, the TPS92010 always operates in current mode control so that the power MOSFET current is always limited. START N RUN = Logic Low LPM = Hi Z N VDD < 8V? REF < 4V? VSD = Logic High? OT = Logic High? OC = Logic High VDD > 13V? Y Continuous Fault Monitor Y RUN = Logic High LPM = Hi Z Soft Start RUN = Logic Low Monitor VFB V FB < 1.4V 1.4V < VFB < 2.0V V FB > 2.0V Fixed V/s 40kHz LPM = 0V (In Run-Mode) LPM = 0V (In Run-Mode) V FB < 0.5V Fixed V/s Freq. Foldback (Light Load) Quasi-Resonant Mode or DCM (Normal Load) N Y Zero Pulses LPM = Hi Z (In Low Power Mode) LPM = 0 V (In Run-Mode) Fixed V-sec 40 kHz Burst N Y Y V FB > 1.5V? N V FB > 1.2V? UDG-09136 Figure 1. Control Flow Chart 8 Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TPS92010 TPS92010 www.ti.com fSW SLUSA14 – DECEMBER 2009 SS Mode (fixed fSW ) QR Mode (ZVS) DCM (maximum fS) Constant Voltseconds (ZCS) Low Power Mode Switching Frequency fMAX = Oscillator Frequency (130 kHz) fSS (40 kHz) This mode applies bursts of 40 kHz soft-start pulses to the power MOSFET gate. The average fSW is shown in this operating mode. fLPM_MX (40 kHz) fQR_MIN : (internally limited to 40 kHz. t Hysteretic transition into Low Power Mode. Feedback Voltage VFB Power Supply Output Voltage t VOUT Low Power Mode, PFC bias OFF t Peak MOSFET Current LPM, pulled up to VDD t VLPM Load shown is slightly less than overcurrent threshold IC Off Softstart Regular Operation Fixed Frequency Frequency Foldback t Low Power Mode Load Power POUT POUT t UDG-09137 Figure 2. Operation Mode Switching Frequencies Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TPS92010 9 TPS92010 SLUSA14 – DECEMBER 2009 www.ti.com Under normal operating conditions, the FB pin commands the operating mode of the TPS92010 at the voltage thresholds shown in Figure 3. Soft-start and fault responses are exceptions. During soft-start mode the TPS92010 controls the converter at a fixed constant switching frequency of 40 kHz. The soft-start mode is latched-OFF when VFB becomes less than VSS for the first time after UVLOON. The soft-start state cannot be recovered until after passing UVLOOFF, and then, UVLOON. VFB (V) 5.0 Internal Reference 4.0 VFB Control Range Limit QR Mode or DCM Mode 2.0 fSW = 130 kHz Frequency Foldback Mode 1.4 fSW = 40 kHz Low Power Mode 0.7 0.5 Burst-ON Burst-OFF Burst Hysteresis 0 Figure 3. Mode Control with FB Pin Voltage At normal rated operating loads (from 100% to approximately 30% full rated power) the TPS92010 controls the converter in quasi-resonant mode (QRM) or discontinuous conduction mode (DCM), where DCM operation is at the clamped maximum switching frequency (130 kHz). For loads that are between approximately 30% and 10% full rated power, the converter operates in frequency foldback mode (FFM), where the peak switch current is constant and the output is regulated by modulating the switching frequency for a given and fixed VIN. Effectively, operation in FFM results in the application of constant volt-seconds to the flyback transformer each switching cycle. Voltage regulation in FFM is achieved by varying the switching frequency in the range from 130 kHz to 40 kHz. For extremely light loads (below approximately 10% full rated power), the converter is controlled using bursts of 40-kHz pulses. Keep in mind that the aforementioned boundaries of steady-state operation are approximate because they are subject to converter design parameters. Refer to the typical applications block diagram for the electrical connections to implement the features. 10 Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TPS92010 TPS92010 www.ti.com SLUSA14 – DECEMBER 2009 Details of the functional boxes in the Block Diagram are shown in Figure 4, Figure 5, Figure 6 and Figure 7 showing how the TPS92010 executes the command of the FB voltage to have the responses that are shown in Figure 3, Figure 1 and Figure 2. The details of the functional boxes also show the various fault detections and responses that are included in the TPS92010. During all modes of operation, this controller operates in current mode control. This allows the TPS92010 to monitor the FB voltage to determine and respond to the varying load levels. Quasi-resonant mode and DCM occurs for feedback voltages VFB between 2.0 V and 4.0 V, respectively. In turn, the PCS voltage is commanded to be between 0.4 V and 0.8 V. A cycle-by-cycle power limit imposes a fixed 0.8-V limit on the PCS voltage. An overcurrent shutdown threshold in the fault logic gives added protection against high-current, slew-rate shorted winding faults, shown in Figure 7. The power limit feature in the QR DETECT circuit of Figure 6 adds an offset to the PCS signal that is proportional to the line voltage. The power limit feature is programmed with RPL, as shown in the typical application diagram. REF + 1.4 V + OSC Peak Comparator OSC_CL 450 kW + 4.0V 100 kW SS_OVR S Q R Q QR_DONE + OSC_CL 0.1V FB 450 kW 100 kW CLK 130 kHz OSC Clamp Comparator + 2.0 V FB_CL + OSC Valley Comparator UDG-09139 RUN UDG-09138 Figure 4. Oscillator Details Figure 5. Mode Clamp Details Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TPS92010 11 TPS92010 SLUSA14 – DECEMBER 2009 www.ti.com CIN RSU NP CVDD Auxiliary Winding RVSD1 NS COUT NB RVSD2 VDD VSD 7 TPS92010 QR Detect 0.1 V + Slope RPCS + QR_DONE (Oscillator) –0.1 V GD (From Driver) 0.1 V + + + REF (5 V) ILINE REF (5 V) Power Limit Offset 3.75 V RPL1 ILINE + ILINE 2 Low Power (from FAULT logic) 1 LOAD_VSD (Fault Logic) 1 kW LINE_VSD (Fault Logic) 0.45 V 0 PCS PCS 3 RPL2 UDG-09223 Figure 6. QR Detect Details 12 Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TPS92010 TPS92010 www.ti.com SLUSA14 – DECEMBER 2009 TPS92010 REF UVLO SET D Q REF_OK Thermal Shutdown Q CLR OVR_T REF (5 V) RUN LINE_VSD (QR Detect) SS/DIS LOAD_VSD (QR Detect) 20 kW Q R Q + 0.6 V/0.7 V FB S 1.25 V 7 + Low Power Power-Up Reset 0.6 V/1.5 V FB Low Power 8 LPM + SS_OVR PCS 3 PCS UDG-09224 Figure 7. Fault Logic Details Quasi-Resonant / DCM Control Quasi-resonant (QR) and DCM operation occur for feedback voltages VFB between 2.0 V and 4.0 V. In turn, the peak PCS voltage is commanded to be between 0.4 V and 0.8 V. During this control mode, the rising edge of GD always occurs at the valley of the resonant ring after demagnetization. Resonant valley switching is an integral part of QR operation. Resonant valley switching is also imposed if the system operates at the maximum switching frequency clamp. In other words, the frequency varies in DCM operation in order to have the switching event occur on the first resonant valley that occurs after a 7.7-μs (130-kHz) interval. Notice that the PCS pin has an internal dependent current source, ½ ILINE. This current source is part of the cycle-by-cycle power limit function that is discussed in the Protection Features section. Frequency Foldback Mode Control Frequency foldback mode uses elements of the FAULT LOGIC, shown in Figure 7 and the mode clamp circuit, shown in Figure 5. At the minimum operating frequency, the internal oscillator sawtooth waveform has a peak of 4.0 V and a valley of 0.1 V. When the FB voltage is between 2.0 V and 1.4 V, the FB_CL signal in Figure 5 commands the oscillator in a voltage controlled oscillator (VCO) mode by clamping the peak oscillator voltage. The additional clamps in the OSCILLATOR restrict VCO operation between 40 kHz and 130 kHz. The FB_CL voltage is reflected to the modulator comparator effectively clamping the reflected PCS command to 0.4 V. Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TPS92010 13 TPS92010 SLUSA14 – DECEMBER 2009 www.ti.com Low Power Mode Control Low power mode uses elements of the FAULT LOGIC, shown in Figure 7 and the mode clamps circuit, shown in Figure 5. The OSC_CL signal clamps the Low Power-mode operating frequency at 40 kHz. Thus, when the FB voltage is between 1.4 V and 0.5 V, the controller is commanding an excess of energy to be transferred to the load which in turn, drives the error higher and FB lower. When FB reaches 0.5 V, GD pulses are terminated and do not resume until FB reaches 0.7 V. In this mode, the converter operates in hysteretic control with the GD pulse terminated at a fixed PCS voltage level of 0.4 V. The power limit offset is turned OFF during Low Power mode and it returns to ON when FB is above 1.4 V, as depicted in Figure 7. H mode reduces the average switching frequency in order to minimize switching losses and increase the efficiency at light load conditions. Fault Logic Advanced logic control coordinates the fault detections to provide proper power supply recovery. This provides the conditioning for the thermal protection. Line overvoltage protection and load overvoltage protection are implemented in this block. It prevents operation when the internal reference is below 4.5 V. If a fault is detected in the thermal shutdown, line overvoltage protection, load overvoltage protection, or REF, the TPS92010 undergoes a shutdown/retry cycle. Refer to the fault logic diagram in Figure 7 and the QR detect diagram in Figure 6 to program line overvoltage protection and load overvoltage protection. To program the load overvoltage protection, select the RVSD1 – RVSD2 divider ratio to be 3.75 V at the desired output shut-down voltage. To program line overvoltage protection, select the impedance of the RVSD1 – RVSD2 combination to draw 450 μA when the VVSD is 0.45 V during the ON-time of the power MOSFET at the highest allowable input voltage. Oscillator The oscillator, shown in Figure 4, is internally set and trimmed so it is clamped by the circuit in Figure 4 to a nominal 130-kHz maximum operating frequency. It also has a minimum frequency clamp of 40 kHz. If the FB voltage tries to drive operation to less than 40 kHz, the converter operates in low power mode. Low Power The LPM pin is an open drain output, as shown in Figure 7. The LPM output goes into the OFF-state when FB falls below 0.5 V and it returns to the ON-state (low impedance to GND) when FB rises above 1.4 V. OPERATING MODE PROGRAMMING Boundaries of the operating modes are programmed by the flyback transformer and the four components RPL, RPCS, RVSD1 and RVSD2; shown in Figure 1. The transformer characteristics that predominantly affect the modes are the magnetizing inductance of the primary and the magnitude of the output voltage, reflected to the primary. To a lesser degree (yet significant), the boundaries are affected by the MOSFET output capacitance and transformer leakage inductance. The design procedure here is to select a magnetizing inductance and a reflected output voltage that operates at the DCM/CCM boundary at maximum load and maximum line. The actual inductance should be noticeably smaller to account for the ring between the magnetizing inductance and the total stray capacitance measured at the drain of the power MOSFET. This programs the QR/DCM boundary of operation. All other mode boundaries are preset with the thresholds in the oscillator and green-mode blocks. PROTECTION FEATURES The TPS92010 has many protection features. Refer to Figures 1, 4, 8, 9 and 10 for detailed block descriptions that show how the features are integrated into the normal control functions. Overtemperature Overtemperature lockout typically occurs when the substrate temperature reaches 140ºC. Retry is allowed if the substrate temperature reduces by the hysteresis value. Upon an overtemperature fault, CSS on softstart is discharged and LPM is forced to a high impedance. Cycle-by-Cycle Power Limit The cycle terminates when the PCS voltage plus the power limit offset exceeds 1.2 V. 14 Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TPS92010 TPS92010 www.ti.com SLUSA14 – DECEMBER 2009 In order to have power limited over the full line voltage range of the QR Flyback converter, the PCS pin voltage must have a component that is proportional to the primary current plus a component that is proportional to the line voltage due to predictable switching frequency variations due to line voltage. At power limit, the PCS pin voltage plus the internal PCS offset is compared against a constant 1.2-V reference in the PWM comparator. Thus during cycle-by-cycle power limit, the peak PCS voltage is typically 0.8 V. The current that is sourced from the VSD pin (ILINE) is reflected to a dependent current source of ½ ILINE, that is connected to the PCS pin. The power limit function can be programmed by a resistor, RPL, that is between the PCS pin and the current sense resistor. The current, ILINE, is proportional to line voltage by the transformer turns ratio NB/NP and resistor RVSD1. Current ILINE is programmed to set the line over voltage protection. Resistor RPL results in the addition of a voltage to the current sense signal that is proportional to the line voltage. The proper amount of additional voltage has the effect of limiting the power on a cycle-by-cycle basis. Note that RPCS, RPL, RVSD1 and RVSD2 must be adjusted as a set due to the functional interactions. Current Limit When the primary current exceeds maximum current level which is indicated by a voltage of 1.25 V at the PCS pin, the device initiates a shutdown. Retry occurs after a UVLOOFF/UVLOON cycle. Overvoltage Protection Function Input line overvoltage and LED open string protection is programmed with the transformer turn ratios, RVSD1 and RVSD2. The VSD pin has a 0-V voltage source that can only source current; VSD cannot sink current. Open String LED protection occurs when the VSD pin is clamped at 0 V. When the bias winding is negative, during GD = HI or portions of the resonant ring, the 0-V voltage source clamps VSD to 0 V and the current that is sourced from the VSD pin is mirrored to the Line_VSD comparator and the QR detection circuit. The Line_VSD comparator initiates a shutdown-retry sequence if VSD sources any more than 450 μA. Open String LED protection occurs when the VSD pin voltage is positive. When the bias winding is positive, during demagnetization or portions of the resonant ring, the VSD pin voltage is positive. If the VSD voltage is greater than 3.75 V, the device initiates a shutdown. Retry occurs after a UVLOOFF/UVLOON cycle. Undervoltage Lockout Protection is provided to guard against operation during unfavorable bias conditions. Undervoltage lockout (UVLO) always monitors VDD to prevent operation below the UVLO threshold. Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TPS92010 15 TPS92010 SLUSA14 – DECEMBER 2009 www.ti.com TYPICAL CHARACTERISTICS CLAMP VOLTAGE vs JUNCTION TEMPERATURE SWITCHING FREQUENCY vs JUNCTION TEMPERATURE 140 fSW(max) – Maximum Switching Frequency – kHz 30 VDD – Clamp Voltage – V 28 26 24 22 20 –40 –15 10 35 60 85 110 138 136 134 132 130 128 126 124 122 120 –40 135 –15 85 110 135 Figure 9. PL THRESHOLD vs TEMPERATURE OVERVOLTAGE PROTECTION THRESHOLD vs TEMPERATURE –375 IVSD – Overcoltage Protection Current – mA VPL – Power Limit Threshold Voltage – mV 60 Figure 8. 850 840 –400 830 820 –425 810 800 –450 790 780 –475 770 760 –15 10 35 60 85 110 135 –500 –40 TJ – Junction Temperature – °C Figure 10. 16 35 TJ – Junction Temperature – °C TJ – Junction Temperature – °C 750 –40 10 –15 10 35 60 85 110 135 TJ – Junction Temperature – °C Figure 11. Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TPS92010 PACKAGE OPTION ADDENDUM www.ti.com 10-Dec-2020 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Pins Package Drawing Qty Eco Plan (2) Lead finish/ Ball material MSL Peak Temp Op Temp (°C) Device Marking (3) (4/5) (6) TPS92010D ACTIVE SOIC D 8 75 RoHS & Green NIPDAU Level-1-260C-UNLIM -40 to 105 92010D TPS92010DR ACTIVE SOIC D 8 2500 RoHS & Green NIPDAU Level-1-260C-UNLIM -40 to 105 92010D (1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device. (2) RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may reference these types of products as "Pb-Free". RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption. Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of