L4981A L4981B ® POWER FACTOR CORRECTOR CONTROL BOOST PWM UP TO 0.99P.F. LIMIT LINE CURRENT DISTORTION TO < 5% UNIVERSAL INPUT MAINS FEED FORWARD LINE AND LOAD REGULATION AVERAGE CURRENT MODE PWM FOR MINIMUM NOISE SENSITIVITY HIGH CURRENT BIPOLAR AND DMOS TOTEM POLE OUTPUT LOW START-UP CURRENT (0.3mA TYP.) UNDER VOLTAGE LOCKOUT WITH HYSTERESIS AND PROGRAMMABLE TURN ON THRESHOLD OVERVOLTAGE, OVERCURRENT PROTECTION PRECISE 2% ON CHIP REFERENCE EXTERNALLY AVAILABLE SOFT START DESCRIPTION The L4981 I.C. provides the necessary features to achieve a very high power factor up to 0.99. Realized in BCD 60II technology this power factor corrector (PFC) pre-regulator contains all the con- MULTIPOWER BCD TECHNOLOGY DIP20 SO20 ORDERING NUMBERS: L4981X (DIP20) L4981XD (SO20) trol functions for designing a high efficiency-mode power supply with sinusoidal line current consumption. The L4981 can be easily used in systems with mains voltages between 85V to 265V without any line switch. This new PFC offers the possibility to work at fixed frequency (L4981A) or modulated frequency (L4981B) optimizing the size of the in- BLOCK DIAGRAM November 2001 1/16 L4981A - L4981B put filter; both the operating frequency modes working with an average current mode PWM controller, maintaining sinusoidal line current without slope compensation. Besides power MOSFET gate driver, precise voltage reference (externally available), error amplifier, undervoltage lockout, current sense and the soft start are included. To limit the number of the external components, the device integrates protections as overvoltage and overcurrent. The overcurrent level can be programmed using a simple resistor for L4981A. For a better precision and for L4981B an external divider must be used. ABSOLUTE MAXIMUM RATINGS Symbol Pin VCC 19 20 IGDRV Parameter Supply Voltage (ICC ≤50mA) (*) Gate driv. output peak current (t = 1µs) . VGDRV SINK SOURCE Unit V Α 1.5 A Gate driv. output voltage t = 0.1µs -1 V Voltages at pins 3, 14, 7, 6, 12, 15 -0.3 to 9 V VVA-OUT 13 Error Amplifier Voltage IAC 4 AC Input Current VCA-OUT 5 Voltages at pin 8, 9 Current Amplifier Volt. (Isource = -20mA; Isink = 20mA) VROSC ICOSC IFREQ-MOD 17 11, 18 18 16 VSYNC VIPK 16 2 -0.3 to 8.5 V 5 mA -0.5 to 7 -0.3 to 8.5 V V -0.3 to 3 -0.3 to 7 15 5 V V mA mA -0.3 to 7 -0.3 to 5.5 -2 V V V W Voltage at pin 17 Voltage at pin 11, 18 Input Sink Current Frequency Modulation Sink Current (L4981B) Sync. Voltage (L4981A) Voltage at pin 2 Voltage at Pin 2 t = 1µs Ptot Power Dissipation at Tamb = 70°C (DIP20) 1 (SO20) 0.6 W Top Power Dissipation at Tamb = 70°C Operating Ambient Temperature StorageTemperature -40 to 125 -55 to 150 °C °C Tstg (*) Maximum package power dissipation limits must be observed. PIN CONNECTIONS (Top views) L4981A 2/16 Value selflimit 2 L4981B L4981A - L4981B THERMAL DATA Symbol Parameter Rth j-amb Thermal Resistance Junction-ambient DIP 20 SO 20 Unit 80 120 °C/W PIN FUNCTIONS N. Name 1 P-GND 2 IPK Description Power ground. L4981A peak current limiting. A current limitation is obtained using a single resistor connected between Pin 2 and the sense resistor. To have a better precision another resistor between Pin 2 and a reference voltage (Pin 11) must be added. L4981B peak current limiting. A precise current limitation is obtained using two external resistor only. These resistors must be connected between the sense resistor, Pin 2 and the reference voltage. 3 OVP Overvoltage protection. At this input are compared an internal precise 5.1V (typ) voltage reference with a sample of the boost output voltage obtained via a resistive voltage divider in order to limit the maximum output peak voltage. 4 IAC Input for the AC current. An input current proportional to the rectified mains voltage generates, via a multiplier, the current reference for the current amplifier. 5 CA-OUT 6 LFF Load feedforward; this voltage input pin allows to modify the multiplier output current proportionally to the load, in order to give a faster response versus load transient. The best control is obtained working between 1.5V and 5.3V. If this function is not used, connect this pin to the voltage reference (pin = 11). 7 VRMS Input for proportional RMS line voltage. the VRMS input compesates the line voltage changes. Connecting a low pass filter between the rectified line and the pin 7, a DC voltage proportional to the input line RMS voltage is obtained. The best control is reached using input voltage between 1.5V and 5.5V. If this function is not used connect this pin to the voltage reference (pin = 11). 8 MULT-OUT Multiplier output. This pin common to the multiplier output and the current amplifier N.I. input is an high impedence input like ISENSE. The MULT-OUT pin must be taken not below -0.5V. Current amplifier output. An external RC network determinates the loop gain. 9 ISENSE Current amplifier inverting input. Care must be taken to avoid this pin goes down -0.5V. 10 S-GND Signal ground. 11 VREF 12 SS 13 VA-OUT Error amplifier output, an RC network fixes the voltage loop gain characteristics. 14 VFEED Voltage error amplifier inverting input. This feedback input is connected via a voltage divider to the boost output voltage. 15 P-UVLO Programmable under voltage lock out threshold input. A voltage divider between supply voltage and GND can be connected in order to program the turn on threshold. 16 SYNC (L4981A) This synchronization input/output pin is CMOS logic compatible. Operating as SYNC in, a rectangular wave must be applied at this pin. Opearting as SYNC out, a rectangular clock pulse train is available to synchronize other devices. FREQ-MOD (L4981B) Output reference voltage (typ = 5.1V).Voltage refence at ± 2% of accuracy externally available, it’s internally current limited and can deliver an output current up to 10mA. A capacitor connected to ground defines the soft start time. An internal current generator delivering 100µA (typ) charges the external capacitor defining the soft start time constant. An internal MOS discharge, the external soft start capacitor both in overvoltage and UVLO conditions. Frequency modulation current input. An external resistor must be connected between pin 16 and the rectified line voltage in order to modulate the oscillator frequency. Connecting pin 16 to ground a fixed frequency imposed by ROSC and COSC is obtained. 17 ROSC An external resistor connected to ground fixes the constant charging current of C OSC. 18 COSC An external capacitor connected to GND fixes the switching frequency. 19 VCC 20 GDRV Supply input voltage. Output gate driver. Bipolar and DMOS transistors totem pole output stage can deliver peak current in excess 1A useful to drive MOSFET or IGBT power stages. 3/16 L4981A - L4981B ELECTRICAL CHARACTERISTICS (Unless otherwise specified VCC = 18V, COSC = 1nF, ROSC = 24KΩ, CSS = 1µF, VCA-OUT = 3.5V, VISENSE = 0V, VLFF = VREF, IAC = 100µA, VRMS = 1V, VFEED = GND, VIPK = 1V, VOVP = 1V, TJ = 25°C Symbol Prameter Test Condition Min. Typ. Max. Unit -500 -50 ±8 500 mV nA 70 5.5 100 6.5 7.5 dB V 0.4 1 V ERROR AMPLIFIER SECTION VIO IIB Input Offset Voltage Input Bias Current V13H Open Loop Gain Output High voltage V13L Output Low Voltage Output Source Current -I13 Output Sink Current I13 REFERENCE SECTION Vref –25°C < TJ < 85°C VFEED = 0V VFEED = 4.7V IVA-OUT = -0.5mA VFEED = 5.5V IVA-OUT = 0.5mA VFEED = 4.7V; VVA-OUT = 3.5V VFEED = 5.5V; VVA-OUT = 3.5V 2 4 10 20 mA mA Reference Output Voltage –25°C < TJ < 85°C 4.97 5.1 5.23 V 5.01 5.1 5.19 V ∆Vref Load Regulation Tj = 25°C Iref = 0 1mA ≤ Iref ≤ 10mA –25°C < TJ < 85°C 3 15 mV ∆Vref Line Regulation 12V ≤ VCC ≤ 19V –25°C < TJ < 85°C 3 10 mV Iref sc Short Circuit Current Vref = 0V 20 30 50 mA Tj = 25°C 12V ≤ VCC ≤ 19V –25°C < TJ < 85°C 85 100 115 KHz 80 100 120 KHz 4.7 0.45 5 0.55 11.5 5.3 0.65 V mA mA 0.9 1.15 1.4 V OSCILLATOR SECTION fosc Vsvp I18C I18D Initial Accuracy Frequency Stability Ramp Valley to Peak Charge Current Discharge Current VCOSC = 3.5V VCOSC = 3.5V Ramp Valley Voltage V18 SYNC SECTION (Only for L4981A) tW Output Pulse Width 50% Amplitude 0.3 0.8 µs I16 Sink Current with Low Output Voltage VSYNC = 0.4V VCOSC = 0V 0.4 0.8 mA -I16 Source Current with High Output Voltage VSYNC = 4.5V VCOSC = 6.7V 1 6 mA V16L V16H Low Input Voltage High Input Voltage 0.9 Pulse for Synchronization td FREQUENCY MODULATION FUNCTION (Only for L4981B) f18max f18min Maximum Oscillation Frequency Minimum Oscillator Frequency VFREQ-MOD = 0V (Pin 16) Ifreq = 0 IFREQ-MOD = 360µA (Pin 16) VVRMS = 4V (Pin 7) 3.5 V V 800 ns 85 IFREQ-MOD = 180µA (Pin 16) VVRMS = 2V (Pin 7) 100 115 KHz 74 KHz 76 KHz SOFT START SECTION 4/16 ISS Soft Start Source Current VSS = 3V V12sat Output Saturation Voltage V3 = 6V, ISS = 2mA 60 100 140 µA 0.1 0.25 V L4981A - L4981B ELECTRICAL CHARACTERISTICS (continued) Symbol Parameter Test Condition Min. Typ. Max. Unit 19.5 V 5.1 Vref +20mV V SUPPLY VOLTAGE Operating Supply Voltage VCC OVER VOLTAGE PROTECTION COMPARATOR Vthr V3Hys I3 td Rising Threshold Voltage Vref -20mV Hysteresis 180 Input Bias Current Propagation delay to output VOVP = Vthr +100mV 250 320 mV 0.05 1 µA 1 2 µs 0.4 ±30 0.9 mV µs 85 105 µA 5 µA ±2 mV 500 nA dB OVER CURRENT PROTECTION COMPARATOR Vth td Threshold Voltage Propagation delay to Output Current Source Generator Iipk IL Leakage Current CURRENT AMPLIFIER SECTION VOCP = Vthr -0.2V VIPK = -0.1V only for L4981A VIPK = -0.1V only for L4981B Voffset Input Offset Voltage VMULT OUT = VSENSE = 3.5V I9bias Input Bias Current Open Loop Gain VSENSE = 0V 1.1V ≤ VCA OUT ≤ 6V SVR Supply Voltage Rejection V5H 65 -500 70 50 100 12V ≤ VCC ≤ 19V VMULT OUT = 3.5V VSENSE = 3.5V 68 90 Output High Voltage VMULT OUT = 200mV ICA OUT = -0.5mA, VIAC = 0V 6.2 V5L Output Low Voltage VMULT OUT = -200mV ICA OUT = 0.5mA, VIAC = 0V -I5 Output Source Current Output Sink Current VMULT OUT = 200mV, VIAC = 0V, VCA-OUT = 3.5V I5 dB V 0.9 2 2 10 10 11.5 12.5 V mA mA OUTPUT SECTION Output Voltage Low ISINK = 250mA Output Voltage High ISOURCE = 250mA VCC = 15V tr Output Voltage Rise Time COUT = 1nF 50 150 ns tf Output Voltage Fall Time Voltage Clamp COUT = 1nF ISOURCE = 0mA 30 16 100 19 ns V 0.3 8 0.5 12 mA mA V20L V20H VGDRV 0.5 13 0.8 V V TOTAL STANDBY CURRENT SECTION I19start I19on I19 Supply Current before start up Supply Current after turn on VCC = 14V VIAC = 0V, VCOSC = 0, Pin17 = Open Operating Supply Current Pin20 = 1nF Zener Voltage VCC UNDER VOLTAGE LOCKOUT SECTION (*) 12 16 mA 20 25 30 V Vth ON Turn on Threshold 14.5 15.5 16.5 V Vth OFF Turn off Threshold Programmable Turn-on Threshold 9 10.6 10 12 11 13.4 V V Pin 15 to VCC = 220K Pin15 to GND = 33K LOAD FEED FORWARD ILFF VI Bias Current V6 = 1.6V 70 140 µA V6 = 5.3V 200 300 5.3 µA V Input Voltage Range 1.6 (*) Maximum package power dissipation limits must be observed. 5/16 L4981A - L4981B ELECTRICAL CHARACTERISTICS (continued) Symbol Prameter Test Condition Min. Typ. Max. Unit VVA-OUT = 4V, VRMS = 2V, VMULTOUT = 0, VLFF = 5.1V IAC = 50µA, COSC = 0V 20 35 52 µA VVA-OUT = 4V, VRMS = 2V, VMULTOUT = 0, VLFF = 5.1V IAC = 200µA, COSC = 0V VVA-OUT = 2V, VRMS = 2V, VMULTOUT = 0, VLFF = 5.1V IAC = 100µA, COSC = 0V 100 135 170 µA 10 20 30 µA VVA-OUT = 2V, VRMS = 4V, VMULTOUT = 0, VLFF = 5.1V IAC = 100µA, COSC = 0V 2 5.5 11 µA VVA-OUT = 4V, VRMS = 4V, VMULTOUT = 0, VLFF = 5.1V IAC = 100µA, COSC = 0V VVA-OUT = 4V, VRMS = 2V, VMULTOUT = 0, VLFF = 2.5V COSC = 0V, IAC = 200µA VVA-OUT = 4V, VRMS = 4V VMULTOUT = 0, VLFF = 5.1V IAC = 200µA, COSC = 0V VVA-OUT = 2V, VRMS = 4V, VMULTOUT = 0, VLFF = 5.1V IAC = 0, COSC = 0V 10 22 34 µA 20 37 54 µA 20 39 54 µA -2 0 2 µA MULTIPLIER SECTION Multipler Output Current K Multiplier Gain IMULT−OUT = K ⋅ IAC if VLFF = VREF; 0.37 (VVA−OUT − 1.28) ⋅ (0.8 ⋅ VLFF − 1.28) IMULT−OUT = IAC (VVRMS)2 (VVA−OUT − 1.28) 2 (VVRMS) ⋅ K1 where: K1 = 1V Figure 1: MULTI-OUT vs. IAC (VRMS = 1.7V; VLFFD = 5.1V) 6/16 Figure 2: MULTI-OUT vs. IAC (VRMS = 2.2V; VLFFD = 5.1V) L4981A - L4981B Figure 3: MULTI-OUT vs. IAC (VRMS = 4.4V; VLFFD = 5.1V) Figure 4: MULTI-OUT vs. IAC (VRMS = 5.3V; VLFFD = 5.1V) Figure 5: MULTI-OUT vs. IAC (VRMS = 1.7V; VLFFD = 2.5V) Figure 6: MULTI-OUT vs. IAC (VRMS = 2.2V; VLFFD = 2.5V) Figure 7: MULTI-OUT vs. IAC (VRMS = 4.4V; VLFFD = 2.5V) Figure 8: MULTI-OUT vs. IAC (VRMS = 5.3V; VLFFD = 2.5V) 7/16 L4981A - L4981B Figure 9A: L4981A Power Factor Corrector (200W) L 0.9mH R17 806K 1% R6 620K 5% R17 806K 1% R7 360K 5% R6 620K 5% DZ 22V 0.5W + D1 5TTA5060 R15 10K R14 0.5W 56 Q2 0.5W STK2N50 D3 1N4150 R19 1.1M 5% D3 C7 2N2222 220nF 100V R8 33K 5% C8 220nF 100V R19 1.1M 5% C10 15nF 100V R1 412K 1% R9 910K 1% R1 412K 1% R9 910K 1% D4 1N4150 C11 100µF 25V R23 R20 Vo R22 10K 5% FUSE Vi 88VAC to 254VAC NTC 15 7 4 BRIDGE 4 x BY214 19 14 R12 220K 5% C1 220nF 400V C9 330nF L4981A 3 R11 D2 1N4150 STH/STW15NB50 2 560 1% 8 R21 5.1K 1% 5 9 R3 2.7K 5% RS 12 17 11 6 1 R13 20 C12 270pF 630V Q1 15 5% C3 R5 27K 5% 18 C2 100µF 450V 13 D5 BYT 11600 1nF R4 2.7K 5% R2 11K 1% R10 21K 1% C5 1µF 16V C6 1µF 16V R16 24K 1% C4 1nF R18 1.8K 4W D93IN029C 0.07 2W fSW = 80kHz; PO = 200W; VOUT = 400V; Irms max = 2.53A; VOVP = 442V; IPK max = 6.2A Figure 9B: L4981B Power Factor Corrector (200W) L 0.9mH R22 1.1M R17 806K 1% R6 620K 5% R17 806K 1% R7 360K 5% R6 620K 5% C8 220nF 100V R19 1.1M 5% R19 1.1M 5% D3 C7 2N2222 220nF 100V R8 33K 5% R15 10K R14 0.5W 56 Q2 0.5W STK2N50 D3 1N4150 DZ 22V 0.5W C11 100µF 25V + D1 5TTA5060 C10 15nF 100V R1 412K 1% R9 910K 1% R1 412K 1% R9 910K 1% D4 1N4150 R23 R20 Vo R22 10K 5% FUSE Vi 88VAC to 254VAC NTC C1 220nF 400V 15 7 4 BRIDGE 4 x BY214 19 14 R12 220K 5% 16 L4981B D2 1N4150 2 560 1% 8 5 9 R3 2.7K 5% RS 17 11 6 12 1 20 R13 STH/STW15NB50 Q1 15 5% C12 270pF 630V C3 R5 27K 5% 18 C2 100µF 450V 3 R11 R21 5.1K 1% C9 330nF 13 D5 BYT 11600 1nF R4 2.7K 5% 0.07 2W C4 1.1nF R16 24K 1% C6 1µF 16V R18 1.8K 4W R2 11K 1% C5 1µF 16V D95IN220A fSW = 80 to 92kHz; PO = 200W; VOUT = 400V; Irms max = 2.53A; VOVP = 442V; IPK max = 6.2A 8/16 R10 21K 1% L4981A - L4981B Figure 10: Reference Voltage vs. Source Reference Current Figure 11: Reference Voltage vs. Supply Voltage Figure 12: Reference Voltage vs. Junction Temperature Figure 13: Switching Frequency vs. Junction Temperature Figure 14: Gate Driver Rise and Fall Time Figure 15: Operating Supply Current vs. Supply Voltage 9/16 L4981A - L4981B Figure 16: Programmable Under Voltage Lockout Thresholds Figure 17: Modulation Frequency Normalized in an Half Cycle of the Mains Voltage 1 fsw Vl 1 0.8 0.8 0.4 0.4 0.2 0.2 R22 = R23 ⋅ 6.8 0 45 0 R23 (Kohm) 90 0 135 180 Electrical degrees Table 1: Programmable Under Voltage Lockout Thresholds. VCC ON VCC OFF R22 R23 11V 10V 82kΩ 12kΩ 12V 10.1V 220kΩ 33kΩ 13V 10.5V 430kΩ 62kΩ 14V 10.8V 909kΩ 133kΩ 14.5V 10.9V 1.36MΩ 200kΩ 15V 11V 2.7MΩ 390kΩ Figure 18: Oscillator Diagram 10/16 L4981A - L4981B Figure 19: Demo Board Circuit (VO = 400V; PO = 360W). R14 68 B2= D1+D2 +D8+D9 R4 1.2M C2 330n C3 330n F1 T15A250V R5 220k R12 56k BRIDGE B1 8A C10 150uF L1=0.5mE42*21*15 gap=1.9 58/6 turns 20*.2mm R11 56k R6 500k VCC Dz1 18V R7 500k L2 3u C8 100n R2 33k NTC 2.5 V+ BUS=400V D5STTA106 D6 DZW06-48 C11 220n VCC D4-STTH8R06 to220 (/40CW) R18 6.8 2W C14 100n R19 750k R20 750k D7-STTA406 R22 750k R23 750k R16 220k 88 to 264 Vac 7 4 1 13 19 14 C1 330nF 400V Cf .22uF 600V 3 15 L4981A/ B** 6 2 8 5 9 18 C15 220uF 450V 20 16 RAux1 ** D3 10 17 12 11 Cs 330pF R17 15 Q1+Q2# RAux2 R21 19.6k R10 5k Q4 4007 TP1 R1 460 R3 2.2k R8 17k C6 3.3n C9 1n R15 24k C12 1u C13 1u R13 2.2k R9 (RS) 50m // 3*0.15) R24 16.9k R25 1k 2W # // Q1&Q2 TO220*2 STM12NM50 / 7C/W Figure 20: Component Layout (Dimensions 88 x 150mm). 11/16 L4981A - L4981B Figure 20: P.C.B. Component Side (Dimensions 88 x 150mm). Figure 20: P.C.B. Solder Side (Dimensions 88 x 150mm). 12/16 L4981A - L4981B DEMO BOARD EVALUATION RESULTS Table 2. Nominal Power range at 110Vac. Vmains Pout Vout Pin THD PF 88Vac 366W 404Vdc 397W 5% 0.998 Eff. .92 110Vac 370W 406Vdc 395W 2.2% 0.999 .94 132Vac 372W 407Vdc 394W 3% 0.999 .945 Table 3. Nominal Power range at 220Vac. Vmains Pout Vout Pin THD PF Eff. 176Vac 378W 410Vdc 394W 4.7% 0.997 .959 220Vac 381W 412Vdc 395W 6.4% 0.993 .964 264Vac 381W 412Vdc 395W 8.1% 0.987 .964 REFERENCE: AN628 - DESIGNING A HIGH POWER FACTOR SWITCHING PREREGULATOR WITH THE L4981 CONTINUOUS MODE 13/16 L4981A - L4981B mm inch OUTLINE AND MECHANICAL DATA DIM. MIN. TYP. MAX. MIN. TYP. MAX. A 2.35 2.65 0.093 0.104 A1 0.1 0.3 0.004 0.012 B 0.33 0.51 0.013 0.020 C 0.23 0.32 0.009 0.013 D 12.6 13 0.496 0.512 E 7.4 7.6 0.291 0.299 e 1.27 0.050 H 10 10.65 0.394 0.419 h 0.25 0.75 0.010 0.030 L 0.4 1.27 0.016 0.050 SO20 K 0˚ (min.)8˚ (max.) L h x 45˚ A B e A1 K H D 20 11 E 1 0 1 SO20MEC 14/16 C L4981A - L4981B mm DIM. MIN. a1 0.254 B 1.39 TYP. inch MAX. MIN. TYP. MAX. 0.010 1.65 0.055 0.065 b 0.45 0.018 b1 0.25 0.010 D 25.4 1.000 E 8.5 0.335 e 2.54 0.100 e3 22.86 0.900 F 7.1 0.280 I 3.93 0.155 L OUTLINE AND MECHANICAL DATA 3.3 0.130 DIP20 Z 1.34 0.053 15/16 L4981A - L4981B Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of STMicroelectronics. Specification mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics. The ST logo is a registered trademark of STMicroelectronics © 2001 STMicroelectronics – Printed in Italy – All Rights Reserved STMicroelectronics GROUP OF COMPANIES Australia - Brazil - Canada - China - Finland - France - Germany - Hong Kong - India - Israel - Italy - Japan - Malaysia - Malta - Morocco Singapore - Spain - Sweden - Switzerland - United Kingdom - United States. http://www.st.com 16/16